The light is a Home Depot "Commercial Electric" Shop Light which uses an electronic ballast - a Sunpark SL15. The fixture sells for only$6.49 at the local Home Depots. Electronic fluorescent ballasts have become recently popular and can drive lamps more efficiently and ata higher frequency, which eliminates hum. Electronic ballasts are designed to power the newer and more efficient T8 bulbs on the market,but can also operate the old standard T12 bulbs. (T12 = 12/8 inch diameter, T8 = 8/8 inch diameter). Side by side, 32w T8 bulbs in thiselectronic ballast fixture are brighter that 40w T12 bulbs in a magnetic ballast fixture. That is just the start. Although I bought and playedaround with many types of electronic ballasts (32w, 59w, 110w, HO, etc) I ended up buying many of the Home Depot fixtures after findingout what I could power with them, mainly by "overdriving".

Overdriving (which requires a ballast that drives 2 or more lights) involves disconnecting the wires from both ends of one lamp's socket,and join them to the wires of the the other lamp. This results in a 32w lamp being driven to output approximately 1.7 times as much light asnormally produced. This will reduce the life of the lamp, somewhat, but in the overall picture it is very economical to replace a 32w bulb -even twice as often. With fluorescent lights, over 95% of the total cost of using the bulb is the electricity, since the bulbs last so long tobegin with. I used both a current meter and a light meter to compare my results. The 1.7 times figure was verified by anotherexperimenter I read and your own eyes can DEFINITELY see the difference.

The Sunpark SL15 ballast has 2 red wires and 2 blue wires going to one side of the fixture, with 1 blue, 1 red, and 1 yellow wire going tothe other end of the fixture. On the first end, combine 1 blue wire to 1 red wire (either one), then the other blue to the other red wire. Onthe other end, combine the single red to the single blue wire. The yellow wire on one end will also be jumpered from one socket to theother. Just remove the jumper from the unused socket. Now, one socket will have a red/blue attached to each side of the socket. Theother socket will have a red/blue and a yellow attached to it. You have "paralleled" the ballast output and can now drive an incredible arrayof standard bulb types: 48"-32w, 48"-40w, 36"-30w, most any 24" bulb. They make a Gro-Lux bulb VERY much brighter than normal. Iactually lit bulbs that would no longer light in a normal fixture.

The coolest discovery of all, though, was that I could really light up some special bulbs I was interested in. The power compact twin-tubeT5 bulbs that come in 36,40,50 and 55 watts (and are about 22" long) could also be lit. The 40w bulb was INCREDIBLY bright. In thiscase, one $6.50 ballast with one FT40w (also called PLL40, Dulux-L 40) bulb was WAY brighter than a normal 40w 2-bulb fixture. I alsowas able to light up a 54w T5 High Output to a blazing fury. Those 54w bulbs are recent, very efficient (lumens/watt) bulbs on the market.I built a fixture with 4 54wattT5HO bulbs and 4 Sunpark SL15 overdriven ballasts which is as bright as a 250w High Pressure Sodium.

I must issue a warning or two. If you don't know much about working with electricity, you should read up on electrical wiring techniques andsafety first. I learned electronics just by playing around with the stuff all my life. It is not difficult to do, though. The other warning is thatone pallet of fixtures that one of the Home Depot stores got in had a slightly different ballast with only two wires going to one end instead ofthree. The ballast apparently worked on a slightly different principle and could NOT be overdriven.

So basically, all you need to do is buy 2 fixtures, remove the ballast from one and mount it in the other fixture. Then overdrive them both.One hell of a bright light. I also took my Dremel and cut some of the fixtures shorter to make 36" and 24" fixtures, also overdriven withthose ballasts. I obviously had lots of spare time.

I guess the most important thing to mention is that I put some houseplants under my overdriven lights, and they have taken off like I'venever seen them do before. I am loving it.

This is just the kind of info I'm interested in. You may have read some of my posts here. I will have to try out your "hotrodding" of the electronic ballast. I figured this could be done, I just did'nt know how to do it.

Are you using any other bulbs other than gro lux? I just don't like the fact that all the grow bulbs have such low lumens to begin with. Take a look at my post I've linked and see if any of these bulbs look good. They are the highest output I could find for their type. They are all Phillips.

Thanks much,
Mark

ps I'm printing out your post for reference later! Finally someone is doing what I thought could be done. Keep us posted.

The two kinds of bulbs I am going to play with, plantwise, are those good Philips 32w/T8 fluorescents and the PLL40 watt T5 bulbs.

Another note: In the last 3 months I have read and accumulated an extraordinary amount af data on lights and growing. Previously, I had abandoned the idea of using the Gro-Lux bulbs for anything but that cool purple glow because of the low lumen output. Recently, however, I found out that the small amount of light that the bulbs do put out is almost perfectly matched and balanced to the nanometer ranges that chlorophyll requires, and IS a good light source. It just doesn't put out any of the rest of the visible spectrum. I am refering to the standard Gro-Lux, not the Wide-spectrum. Wide-spectrum Gro-Lux is not any better for plants - fish tanks, maybe yes.

I think Philips is a great company. I love their bulbs.

By the way, I am going to see if those self-ballasted compact spirals have a plant use. They, too, are quite efficient.

The gro-lux has been recommended to me by others here. I guess if it has the correct nanometer ranges and you can drive the "...." out of it, then you can't go wrong. I will take your advice. I have also looked at T5's. There is alot to consider when growing under lights. I'm my smaller bonsai under lights and each tree has slightly different requirements...to much to get into right now.

Thanks,
Mark

One thing I am curoius about, is whether overdriving these bulbs may somehow change the frequency of light they emit. For instance, could a bulb with "peaks" in the 450 nm range now output at 550 nm due to the overdriving? In which case, they will appear brighter to us, but be LESS effective to plants. Just a thought.
-sam

Zink,
I am a little confused about one thing. Are you using one Sunpark SL15 ballast for a 2 bulb fixture or one ballast for two 2 bulb fixtures(4 bulbs total)? Why would you have to remove the ballast from each fixture at all...I thought it was just a rewiring of the ballast while it is still inside the fixture. Are you possibly saying that 2 ballasts are put into one 2 bulb fixture. Sorry for the confusion, I just want to make sure I do it right.

You wrote: "So basically, all you need to do is buy 2 fixtures, remove the ballast from one and mount it in the other fixture. Then overdrive them both."

BTW...The Home Depot near my house doesn't carry this "Commercial Electric" shop light. They only carry "Lithonia" brand. They have 3 Lithonia shop lights all of which are magnetic ballasts. I will call around to the other Home Depots, hopefully they carry yours.

Thanks,
Mark

I hope I can clear a few things up for you.

First, in regards to frequency shift due to overdriving, the light color WILL NOT change. The process is governed by laws of quantum physics which guarantee that it will not shift color. I will explain.

This is the process that happens, either 60 or 120 times a second with magnetic ballasts, or 22,000 to 45,000 times a second with electronic ballasts. The ballast initially provides a high voltage to the filaments at each end of the fluorescent lamp. When the voltage reaches a critical level, the gas in the tube (mainly argon with a little mercury) suddenly becomes ionized, and current rushes through the tube. “Ionization” means an atom now has more, or less, electrons than it normally would contain in it’s outer shell. In this case, extra electrons have been induced to go racing around the “conduction band” of the mercury atoms to get to the other side of the tube. Sufficient voltage pressure is created by the ballast to force the gas into ionization.

In the process, the electrons in the outer shell of the mercury atoms randomly pick up extra energy and go into a higher sub-orbit that normal. Those electrons then drop back to the original orbit as soon as possible, which releases an EXACT amount of energy (a quantum level) as a photon. That photon will ALWAYS be an exact color frequency based on the atom and it’s outer-shell electron. As far as the mercury atoms go, this will actually be ultra-violet light (UV), and is not the final color output of the lamp.

The actual color that is emitted from the tube is based on the type of phosphors which coat the inside of the tube. The same process that I just described above is repeated there, at the phosphor coating, when the photons from the mercury atom hit the tube. There the UV photons are absorbed by the phosphor compounds and re-emitted at the SPECIFIC QUANTUM LEVEL, or color, as the phosphors had been designed to emit. The photon(s) emitted cannot possibly violate the energy levels set by nature. More ENERGY (by overdriving) will translate to more LIGHT. In this case, it is just as if you shone more light on an object, and it got brighter, not colored differently.

A side note: Fluorescent lights have notoriously been known for flicker. This is because with magnetic ballasts the lamp actually drops out of ionization and get re-ionized 60 times a second. Electrical engineers discovered that once you speed the process up to at least 4,000 Hz, the gas stays ionized. This is also a bit more efficient. And, since the notorious hum would now become a squeal, engineers design electronic ballast to oscillate above the range of human hearing. No more noticeable hum.

Now, for the Home Depot fixtures.

They are sold here locally (Louisville, KY) in a grey and white box marked Commercial Electric Shoplight, with the word Shoplight in larger letters. The part number is 140-904. They do NOT say anything about the ballast inside, and the HD employees would not be expected to know that either. I did notice that above the UPC code on the back is HBSL-15, a reference to the Sunpark SL15 ballast. That is the only indication I ever saw on the box. Our local Home Depots seem to have had these fixture constantly in stock for at least 10 months (when I noticed then). Oddly, in my nearest HD store, they currently have a pallet of these shoplights which has a ballast that looks the same, but without a label, and has only 2 wires (1 red + 1blue) coming out of one end. That end of the lamp is wired slightly different, and is NOT the correct ballast to use. This incorrect ballast DOES have the HBSL-15 written on it, but IS NOT the “overdriveable” ballast. The correct ballast has 3 wires (1 red, 1 blue and common yellow) out of one side, and 4 wires (2 red + 2 blue) out of the other side. There also are the black(hot) and white(neutral) wires which I did not mention.

After purchasing the wrong fixture once, I decided to open the box in another Home Depot and look. They had a fresh shipment of the shoplights in and they WERE the correct ballast. What was going on with that one odd shipment, I do not know. I would open the box first and check for the Sunpark SL15 label on the ballast AND that there are 1 red/1 blue/1 yellow wire coming from one side of the ballast

Finally, the needed details.

The fixture uses a single ballast to operate 2- 48” lamps. Essentially, what I am doing to “overdrive” is to use that TWO-lamp ballast to drive only ONE lamp. I am removing the wires going to lamp #2, and pairing them up with the wires going to lamp #1. (There is really no designated #1 or #2 lamp in the fixture. That is just for the explanation.) That will “overdrive” one lamp to about 1.7 times its normal output. That is why I said to buy second shoplight, and transfer the ballast to the first shoplight, then overdrive the second lamp, too. You will now have 2-lamp fixture which puts out more light than 3 lamps. Each bulb is being powered by it’s own 2-lamp (but inexpensive) ballast.

I will describe again how to do it, but first, you will be glad to know that most ANY multi-lamp electronic ballast can do this. Not only that, but you can also do a 3x and 4x overdrive with a 4-lamp ballast, but the efficiency drops. (4x is only 2.4 times as bright as normal). Home Depot sells a GE ballast for 4 lamps, B432I120RH. Another commonly available 4-lamp ballast is the Advance REL-4P32-SC. Both of these can be used to make an overdriven 2-lamp fixture. These two ballasts are Instant-Start as opposed to the Sunpark being Rapid-Start. Instant-Start fixtures have only one wire normally go to each socket with the socket’s two connectors being shorted together. I have overdriven all of these ballasts with pleasing results.

As for the Sunpark:

On one side of the ballast, there are 2 red wires going to one lamp socket and 2 blue wires going to the other lamp socket. Disconnect the one set of wires to one socket (either both reds or both blues) and connect them to the other socket’s two wires. Connect any 1 red to any 1 blue and then the other red to the other blue. Which red to which blue does not seem to matter. It just works every time. On the other side of the ballast, there is 1 red wire going to one socket, 1 blue wire going to the other socket, and a single yellow “common” wire that is shared by both sockets. Combine the red wire to the blue wire and leave the yellow wire in place. You will have to remove the yellow “jumper” wire you will see between the sockets. That is how they normally share the yellow wire. The only annoying part is learning the art of twisting and pulling out the wires from the sockets without breaking them off.

If you use either of the other two ballasts I mentioned above, those are Instant-Start. Without going into the technical differences now, the instant-start method has only ONE wire going to each socket, and the socket will have the two connections (lamp pins) jumpered together. They are actually a little simpler to wire together – coupling two wires together instead of two PAIRS of wires.

So far I have overdriven at least 20 ballasts, with no problems. You will be left with a lot of fixtures - minus a ballast. I used my Dremel tool to cut some of them up and make custom fixtures, reflectors and what not. Try this with overdriving: On the workbench, instead of using one 48”-32w bulb, try lining up 2-24” 17w T8 bulbs in series and jumper two of the bulb end together - sort of making one long 48” bulb. You will find that one Sunpark ballast will overdrive them in series like that. THEN, make yourself a 24” 2-bulb fixture following the wiring you used. You can make a small, really bright fluorescent light that way. I made a 24” 4-bulb fixture using 2 overdriven ballasts.

Even better, instead of the standard medium bi-pin sockets, find a 2G11($3.50) socket and a 22” Philips PLL 40w twin tube compact lamp ($10 or less some places). One 40watt lamp of that type will GLOW LIKE ALL GETOUT with that ballast. Check out the fish/coral forums.

I should try to post the URLs of some of the excellent websites where I learned a lot about this stuff.

I hope this helps. Let me know what you are successful with.

If anyone else tries this, please post the results. Myself, I just gotta remember to actually GROW STUFF instead of playing with lights.

I figured the color temp wouldn't change when driven harder in fluorescents. Incandescents are different if I'm not mistaken. When dimmed,incandescents change color temp. I have used "tungsten" bulbs in photography and they make a 3200K and a 3400K bulb. The 3400K burns up faster since it is driven harder I suppose. My parents have a dimmable fluorescent lamp in their living room and it doesn't get "warmer" looking as it is dimmed. Incandescents on the other hand, get very warm,almost candle like(I think around 2500K?)when dimmed.

Thanks much....I will try out your system sometime after the new year when I get a chance and some free time. Lastly, Do you happen to know how long the bulbs will last when driven harder? I have been changing my bulbs once a year but since bulbs are cheap I don't mind changing more often.

Mark

The URL is: www.plantedtank.net/odno.html

There are a couple of links on that page to more info.

I have overdriven by 4x on my work bench, but I can get more use out of just a 2x overdrive using twice the bulbs. The fish tank people have to try to get as much light over their tanks as possible in a small area, so 4x is often more useful to them.

Mark

However, in a a side by side comparison of a normal lamp and an overdriven lamp, the output is so much brighter that the ability to detect a slight color change is difficult at best.

For those who are interested, here is a link to a major phosphor manufacurer's list of all their lamp phosphors, the exact color of each and the width (or bandwidth) of color peak:
www.nichia.com/lamp.html

I read that this phosphor company supplies 40% of the lamp manufacturers with their phosphors. It is quite a revelation to the technically inquisitive person.

It would probably be a good idea to:
1. Explain a little better how to accomplish the wiring. I was able to pry off the backs of the 4 light sockets without breaking any of the tabs but broke at least one on the other four. From there it was simple to just insert the wires from the other ballast but you made some mention of "twisting" the wires out of the sockets. I dicked around with that for a long time without success.. never did figure out how you were doing that. (?)

2. Explain how to release the stop on the power cable and push it through the fixture so you have enough wire so you don't have to splice wire together to be long enough to get the light sockets in place.

3. How you "mount" the second ballast in the fixture. I took the screw out of the existing one and simply wedged the second one in next to it.

For sure this thing is bright! Hope it has a decent life span.............

Terry Light
Oak Hill, Virginia

The first two is of the side where you have to remove the yellow jumper wire between the two sockets.

The next two are of the side where you combine the blues and reds:

This one shows the power cord crimp twisted out of the fixture to allow more of the cord to be shoved inside the fixture.

The power wires were held together with a crimped connector. I squeezed that connector to undo the ballast wires and then used regular twist on wire nuts to add the second ballast as shown here.

And finally, this shows the two ballasts.

Hope this is some help.
Terry Light
Oak Hill, Virginia

Mark

My question is what does this do to the wattage of these fixtures? I can build them, but my electrical theory is pretty shaky. Does parallelling the ballasts mean that one tube is now using 80 watts instead of 40? So you'd be basically doubling the wattage of all your two tube fixtures? I think I may already have my timer overloaded, and it could be a consideration if you are using extension cords, or have other things on the circuit you're using.

Thanks.

WW

Terry,
In answer to your 3 questions:
1. It was a pain-in-the-butt to figure out how to get the existing wires out of those “push-in-and-stay-in” type sockets. I did not pry the back off of the sockets. I think I did that once, early on, and broke the socket apart doing it. I finally developed the knack of doing what I can only call a “twist and wiggle” technique to get the existing wires out of their slot. Although I can get most of the wires off, I still end up breaking off 10-15% of them. Since you end up with a couple of extra sockets anyhow, you can afford to mess up a few of them. As a last resort, I would have gone ahead and cut and spliced the wires if I couldn’t get the wires wiggled out of the socket. Once you push that wire in, it wants to stay in. Trial and error will hopefully lead to some useable technique.

2. The little plastic power cable “pass-thru clip” on the metal case is a little tricky to get loose, if you need to do that. With the right pair of pliers (I have a needle nose vice grip) you can compress the clip and get it to squeeze out of the hole. I often remove it for one reason of another, but sometimes it is just easier to go ahead and splice the wires that you need to lengthen.

3. You said, and I saw in your photo, that you wedged the two ballasts in next to one another. If that works then use it. I happen to have a lot of screws, drills, and other stuff to use at home. The existing ballast in that particular light is mounted towards one end of the fixture. I just drill a couple more holes somewhere at the other end of the fixture and mount it there. Since the wires are longer on one side of the ballast than the other, I found out that I can turn the second ballast around, mount it on the other end, and the wires will reach just fine. I mount it wherever the wires will conveniently fit right.

By the way, I happened to have spent many years in an optimistic and opportunistic mode while I picked up all kinds of good electrical and electronic junk on our city streets during “junk pick-up week, which is a regular event in all of our neighborhoods. I have even found computers that still work. That is why I have all kinds of stuff to play with and break. Now that I am married, I have a mission to actually use the stuff and not collect it.

WeedWoman,
I have never used the Scotch-lok connectors. If anybody tries them, I would like to know how well they worked for them. My “twist-and-wiggle” technique, to remove the wires, feels like a Zen exercise when I do it. If I am not in the groove, I don’t do well. Wires break off. I take a deep breath. I close my eyes. I take a deep breath. I try again.

As far as wattage goes, I have measured the power consumption while 2x overdriving both 32w and 40w lamps. I measured the power in amps, but converted it to watts here:

Normal (Not Overdriven) 1x
F32T8..... 32.3 watts
F40T12... 29.3 watts

Overdriven 2x
F32T8..... 54.9 watts
F40T12... 51.9 watts

These measurements are per 1 bulb. The brand of lamp is insignificant. The line conditions and the brand of electronic ballast used will alter the readings, but not by much. I have tried other ballasts and got about the same numbers. Notice that the electronic ballast does not double the power consumed. The more times a bulb is overdriven, the less efficient it becomes, as it is starting to drift out of the bulbs optimal design parameters. A 2-bulb fixture, then, would consume 104 watts total. The old magnetic ballasts with F40T12 bulbs consumed about that much per fixture!

OVERDRIVE NOTE:
Since I began investigating the overdrive phenomenon, I have done a great deal of reading on both the electronics theory behind how it works and testimonials from real world users. Actually, there are several ballast manufacturers(Fullham, Workhorse, Icecap, etc.) who have been producing high performance electronic ballasts for many years now. Many of these ballasts are designed to drive a wide range of bulbs, with full understanding that many of the allowable bulb combos are definitely being powered by more current than they were initially built for. Those ballasts were DESIGNED to be able to do that, and this is exactly what people in-the-know with fish and coral tanks have been doing for years. I was delighted to read several discussions by electrical engineers who discussed how it works, and why it is a good way to get more light from a bulb. The only detrimental effect, they pointed out, was a reduction in lamp life. I do not think the reduction in lamp life is significant, or much of a factor in practical use. The people who have recommended this have usually stated that they change their bulbs at least once a years anyhow, and do not have a burn-out by then. I have had 2x overdriven lamps burning for 12-18 hours a day for nearly a year now- with no burn-outs yet. Most ALL of the electronic ballasts I have played with were capable of a variety of overdrive scenarios.

I am the guy who began this thread by posting the ballast rewiring technique. I first saw it being discussed in several of the ‘fish and coral” forums on the web. I started looking for, and studying, everything I could find on the how’s and why’s of overdriving electronic ballasts. The folks in those forums always described their success with great exuberance. The key thing is the ballast must be the newer electronic, not the older heavy magnetic type.

I had full confidence that I could easily do it. I have a degree in Electrical Engineering Technology and have spent many years designing and building my own power supplies and musical effects. I understand the basics of what overdriving is doing.

First, I am not “gutting” the ballast. I am rewiring the outputs of the lamps. Electronic ballasts which operate more than one lamp often show several wiring options, depending on how many lamps you are going to use. What rewiring to overdrive lamps does is cause the circuitry to see a different load drawing the current. The output transistors can do this and still be functioning within proper specifications. The most telling thing about the results is that, using a 2x overdrive, the ballast draws less power with one lamp than it would draw normally with 2 lamps. The two output transistors are teaming up and actually drawing less amperage than normal (with 2 lamps).

I wanted to supply you with a link of a discussion I read between a couple of Electrical Engineers with PhD’s. They discussed the subject at length and completely validated using e-ballasts that way. I searched a while, but could not find the link. I will search again when I get home. Their comments, more than any, made me realize this was a good way to make really bright light.

I have done the same sort of thing with several computers I built. Microprocessors are almost always capable of running faster, but are “crippled” by Intel and AMD for marketing scale purposes.

Unlike the microprocessors running at a higher speed, the overdriven ballasts are actually running below their normal capacity, sharing the duty, and drawing less than normal. I have done this with 7 different types and wattages of electronic ballasts and they ALL worked well.

I would like to hear from Lightt and anyone else who might have done an overdrive rewiring. How is it working? Are you happy with the new level of light you’re getting?

thanks for all the information :) This forum has been very helpful for me. You seem like you won't mind a question from someone else(I hope!)

I have an eight foot/four bulb Lithonia light T8 fixture from home depot. They cost, without lights, about $37.00. Our Home Depot's in Kansas City do *not* have the smaller 4 foot/2 twin light T8 fixtures yet(still the old T12 humming type.) What I don't get....is why would I want to remove a light from each end of this four-light fixture?.. in other words, if I did what you are saying, I would go from 4 lights to two on this fixture, right..? Yes, the two lights would be brighter than the two it would replace, but not as bright as having the orginal four...

What am I missing?

thanks for any help,

Scott(I can do basic wiring in my house and know enough to run everything through a GFCI just in case...)

I might be able to answer your questions better if knew what that Lithonia fixture looked like. I first thought you must have 4-8’ bulbs in your fixture until I looked at a Lithonia catalogue and saw they sell “tandem” 2-bulb 48” fixtures in a 96” length (2-48” + 2-48”). Is that what they are? Since you also said they were T8’s, it is an electronic ballast, I assume. If you could give me the HD part number or the Lithonia model number and the ballast model name/number, I might be able to tell you something.

I can tell you about the ballast removal. The fixture I had referred to in the above posts was the el-cheapo Commercial Electric Shoplight 140-904. I just saw them in the HD online site and they were marked “backordered”. It was those fixtures that I used.

What I would do is buy 2 of the fixtures ($14.50 total), remove the ballast one of the fixtures and mount it in the other fixture. I then had a leftover shell of a fixture, with 4 extra sockets to use if I ever needed. I then could dedicate one ballast to one bulb. I disconnected the wires, as described in previous posts, from four sockets (2 bulbs) and joined them together (see photo above) into only two sockets (1 overdriven bulb).

I really bought extra fixtures, at $7.25 apiece, just to get the ballasts out of them. I mounted the ballasts in all kinds of homemade configurations. I had amassed a LOT of fixtures over the years, mostly throwaways, to see if I could do something with them. I have tools, voltmeters, a lightmeter, and a big work area, so it was easy to goof off with the stuff. The $7.25 fixture/ballasts made it all worth playing with.

Your Lithonia ballast is probably overdriveable, but I have seen 2 electronic ballasts that were not. You would NOT have to remove your ballast(s). What you need is another ballast, per bulb, to ADD to you fixture. I have bought a couple 4-bulb ballasts, such as the GE B432I120RH and Advance REL-4P32-SC which I rewired to overdrive 2 bulbs each. You could buy one of those and overdrive your other 2 bulbs. To use the above info I gave you, I am assuming that your 96” fixture is actually tandem 2-48” fixture with 4-32w T8 bulbs. Is that correct?

Yes, it is the tandem one you discribed (2-48" fixture with 4-32w T8 bulbs. Thanks for checking. Funny, I read over that a few times-thought I got it right!) No where in town was I able to find el cheapo T8's anything. I think HD dumped all the excess T12's here. The 96 inch tandem fixtures the only T8's available...Looked at Lowes also. nada. Hard to believe but I really searched....

I just checked the Lithonia fixture ballast. The fixture has one ballast that runs all four 48" T8 lights. The ballast information is: Quicktronic Electronic Ballast, Sylvania, QT4x32x8 120 ISN SC 120V 60H .95 Amps

I think what you are saying is if this ballast can be overdriven, then I would add another similar ballast-only it would run two lights on one side and the original stock ballast would run the other two.

Where would I put this second ballast? I suppose there is room on the other side of the 96" fixture. Where would I find such a ballast to add?

Amazing to think if this works, I could increase my light output by 70% per bulb. It is bright already!

Thanks again. I know you don't get paid for this!

Scott

A Rapid Start ballast has 2 wires connected to each socket because it initially sends a pre-heating current through the filament in the bulb’s end to aid in the initial ionization of the mercury/argon gas. An Instant Start ballast is designed to provide a higher starting voltage, eliminating the need to pre-heat the filament.

You will just have to figure out where to mount another ballast, or two. You will need either to acquire 2 2-lamp ballasts to overdrive the other bulbs, or 1 4-lamp ballast. Since you already have an Instant Start ballast, you ought to buy the GE/Magnatek B432I120RH that Home Depot sells. It is also a 4-lamp Instant Start electronic ballast, about $25, plus or minus a few bucks if I remember.

your patience with me is admirable. I'm headed to HD tomorrow to get the GE/Magnatek ballast.

This is exciting. I did not know about this until I saw your post.

Plumerias, from the equator, are very high light plants. In the greenhouse, the only thing I *never* controlled was light. Now it is the one thing I really need to understand and understand quickly. I have learned so much from all of you. This forum is a godsend. If anyone knows how the spectrum changes from the equator to say, 39N, I'd like to know. I'd like to replicate the spectrum of the equator if possible. Also, I'd like to replicate approximate footcandles of the equator as well....

The controversy surrounding this reminds me of when I started to use a non vented heater in my greenhouse. If it was killing people en masse you'd hear about it-. There are a lot of posts on Google about overdriving fluorescent lights. Like... it is mentioned all over the internet.

I will keep you posted..Everything on GFCI just in case...

thanks,

Scott

Several weeks ago I was thinking about upgrading (read: organizing!) the setup I've been using for starting tomato plants and happened across this forum and this thread was near the top of page one. Between Zink's explanation and enthusiasm I figured 15 bucks was worth the experiment. I didn't even plug in the tubes prior to taking apart the fixtures so I have no comparison there. What I can say is these overdriven T8's appear to be well more than twice as bright as the T12 fixture. While it's too early here to be starting tomatoes, I went ahead and planted some pepper and herb seeds two weeks ago. The first week I ran the fixture 24 hours a day (for some additional heat) but once I had some germination I put the fixture on a timer and now have the lights on 13 hours a day.

I'll undoubtedly be able to provide much better feedback in a couple months regarding growth and durability but at this point I couldn't be happier with the brightness my eye perceives.

Terry Light
Oak Hill, Virginia
p.s. If someone has a suggestion for some kind of flowering house plant I'm certainly willing to see how it does under this thing!

I tried, once again, using Google to locate the discussions I had read between several PhD level Electrical Engineers who WERE lighting experts. They discussed the “overdrive” effect and how it is a good and well-established approach to obtaining more useable fluorescent light. One problem I had in searching is that they did NOT use the term “overdrive” in their discussion. Probably because in their eyes it was a simple circuit reconfiguration which has already been known and has been in use for years by others.

One relevant fact – The reason that your store-bought fixtures do not already do this is because of the efficiencies mandated by such things as the 1992 Energy Act, which requires standards of environmental impact and energy efficiency. Overdriving IS less efficient use of energy, but for the special case of the grower or fish tank enthusiast it is a welcome application for their hobby.

I did not even try this until I began searching the web. I normally am a very good searcher and I have many tricks to find info on nearly anything I want. I have to say I was ABSOLUTLEY OVERWHELMED at the amount of information I discovered about the subject. This “overdriving” effect has been a standard, used and perfected, for YEARS in the realms of the “Fish and Coral” enthusiasts. I their eyes I am a total NEWBIE to this OD trick.

If you want to become as reassured and knowledgeable as I am I can only suggest the following.

Go to www.google.com. Try both the “Web” and “Groups” sections.

Enter various different combinations of these words: ballast, overdrive, fluorescent, 2x, 4x, workhorse, icecap, fullham, OD, ODNO, OVDR, output, “more light”

If you come up with a bunch of hits full of mindless garbage, you may have to include the term keyphrase -“net-abuse”, with the quotes aand the minus sign in front, to remove some junk posts from some idiots.

It made me feel like someone who thought the world was flat and found out everyone else already knew it wasn’t. I am years late in doing this compared to others previously in the know. I, too, had your cautious questions in mind, but I found out what I needed to know and understood what was going on.

I do not recommend that anyone do this without recognizing the cautions one needs to take around electricity. The starting voltage generated by a ballast is several times normal house current.

I have the GE B432I120RH ballast now(it has that number but not Magnetek. It says Universal Lighting technologies.) It was $27 plus tax, just under $30 at HD. I checked again, still no 2 bulb T8's yet.

The Way It is Now:
I have opened up the fixture and can see the one ballast driving all four lights. (I wish there was a way to draw here...)

You have the yellow wires attaching to the four sockets at the far ends of the fixture. check.

then you have the two reds powering the other end of the bulbs(situated in the middle of the fixture) and the blues powering the other two(the other two sockets at the center of the fixture.)

Procedure to Overdrive:
Ok. It looks like I will take the two blue wires from the original ballast and connect them to a single socket on that side. Then on the new side, I will do the same. Same with reds. Question: This still requires doing the jiggle technique, right?

Then what about the yellow wires? They have that jumper(white short wire)between the sockets. Just cut that out and attach a yellow wire to each end(meaning the end of the fixture) socket?

The net result: that each ballast powers the two bulbs on that side, right? No more crossovers. I just want to make sure. I always try to error on the side of caution.

The white and black wires are a no brainer. Just connect them.

The good news. There is another mount on the other side for the ballast.

It looks like I will need extra wire for the new ballast. Home Depot sells this I'm sure...

Anything else. What if I screw it up...Will I kill both ballasts? Will sparks fly?

I rewired a lot of my old home but never worked with ballasts. I just want to make sure I'm not missing anything.

Thanks,

Looking forward to trying it out.

Scott

After reading your post, I wrote the instructions below. Then, after reading over them, I decided that a picture is worth a thousand words. I am going to post a CLEAR DIAGRAM showing the BEFORE and AFTER for both a Rapid Start and an Instant Start ballast. I am going to attempt to do this within the next 24 hours, if I can figure out how to upload a graphic to this forum. Otherwise, I will refer you to a site to view my diagram. You may want to wait until I do this, because my diagram should make the wiring a no-brainer. That should end a lot of typing.

Now for the wordy part:

Since you are gonna do this, we shall vow to avoid both sparks and ballast killing. If you read all of the following, I think you will know what you are doing. And as for the “jiggle” technique - actually twisting and pulling at the same time - I was describing removing existing wires from their sockets. All of the fluorescent sockets I have ever seen have connections where, once the wires are pushed in, they require some self-learned trial-and-error method to get them back out. Often they break off right at the point you need to re-insert a different wire. I hate that. Luckily, there are almost always 2 insert slots for EACH of the 2 connecting points. In the case of an Instant Start ballast (what both of yours are) you can probably still rewire with at least one broken end stuck inside the socket. With luck, you may not even have that problem. Also, if you have any non-working fixtures around, you can scavenge a socket if you need one.

Now, I want to make sure that I know you comprehend one thing in particular about the sockets. The basic fluorescent bulb, or lamp, has two pins at each end of the tube. These two pins plug into the socket. On the T8’s and T12’s, this 2-pin plug and socket are called “medium bi-pin”. Inside the lamp, each pin attaches to one end of a heating filament. The socket itself has two connection points to insert wires from the ballast, one connection point for each of the two pins on the bulb. Each one of those two connection points usually has two “self-grasping” slots to insert a wire into. In other words - 4 little insert slots for wires on each socket.

With a Rapid Start ballast (not what you have), a separate wire goes from the ballast to each of the 2 connecting points on the socket. After the lamp starts up, each of the wires is supplying current to it’s side of the bulb.

With an Instant Start ballast (what both of your ballasts are), only ONE wire runs from the ballast to each socket. There, at the socket, there should be a short jumper wire between connection points which links the 2 pins of the bulb together. This SINGLE ballast wire can supply current to both ends of the lamp’s filament at once, because the jumper wire is there. This jumper is a necessary connection for an Instant Start ballast, so that the lamp works correctly. There are some sockets used by manufacturers that already have an internal jumper in the socket - for Instant Start ballast use only. I haven’t seen one of these, but take note if you have this type. I will tell you about that in following paragraphs.

For anyone else reading this, the following information is for 4-lamp Instant Start ballasts only (what you have, Scott) to overdrive 2 lamps by 2x.

Since I cannot see which of the red and blue wires go to which of the lamps, I will tell you this. What you want to do is, either - pair up 2 reds and 2 blues (preferred for simplicity), - or - pair up a blue/red and a blue/red. You probably have several wires that are quite long going to the tandem fixture. If you want, you could shorten them to the length you need, and use the pieces you cut off for extra wire. (Years ago, I ran into a dumpster full of blue, red, yellow, black and white ballast wires from some retrofit job at a building. I got this funny feeling about them and took a LOT of them home. Well, what do you know?)

On the other side of the ballast(s) you will have 2 yellow wires. One wire usually runs to just one side of one socket. There will then be a jumper wire, from that socket, to the other socket at that end of the fixture. Each of those 2 sockets should have a smaller jumper wire to short the connecting points (lamp pins) together. What you want to do is REMOVE (or cut) the longer jumper (between the two sockets) and leave the short jumpers (the ones shorting the lamp pins). Now, that yellow wire is supplying just one lamp socket, instead of two.

Remove the second yellow wire, which should be running to the tandem fixture side, from the socket it is inserted into. Then re-attach that yellow wire into the socket you disconnected (the one where you removed or cut the jumper). You have finished the “yellow” side of the first 2 lamps.

Note:
Now you know what the function of the smaller jumpers are - to short the 2 lamp pins at the end of the tube together for an Instant Start ballast. If you find you have the type of socket with the lamp pin connections already shorted, then good. You do not need to short them together.

On the RED and BLUE side of the ballast, you will be pairing up either red/red and blue/blue - or - red/blue and red/blue, as described above. (Repeated experiments have shown that either way will work). Insert one wire into one side of the socket (the lead to one lamp pin) and the other wire into the other side of the socket (the lead to the other lamp pin). If you have the kind of sockets which are already internally shorted, you must connect your pair of wires together at the socket. If so, there probably will be 2 push-in slots at that spot. Once you have one pair of wires going into each socket you are finished with that side.

Now, you will have the wires that once went to 4 sets of sockets (4 lamps driven normally), going to 2 sets of sockets (2 lamps overdriven).

The second GE ballast you bought should be wired in exactly the same way as the Sylvania. They are both Instant Start and the wire colors are the same. Just mount it on the second fixture side and duplicate the wiring. Finish by wiring the AC supply wires together and remember to keep the ground wire attached. Don’t forget: black-HOT, white-NEUTRAL, green(usually)-GROUND.

Remember, I will be posting a GOOD DIAGRAM soon, if you got lost in my explanation above.

Excellent. Very hard to find experts who are willing to be as generous as you are

"If you have the kind of sockets which are already internally shorted, you must connect your pair of wires together at the socket." My Question: Does this mean they go in the same hole on one side of the socket?

"If so, there probably will be 2 push-in slots at that spot."
Yes, there are two holes on each side of the socket(total of 4 per socket.)The two top holes look like they are for the short the lamp pins.

"Once you have one pair of wires going into each socket you are finished with that side."
My Question: Can I put the both blue wires on both sides of the individual socket or are you saying to tie them together and have them go in one hole....? I am talking about the blue and red ones here. What happens if I put them on both sides of the socket?

I think I have the short jumpers (the ones shorting the lamp pins)that are hard to see inside the socket. I can see them, but I have to turn the socket upside down and look in the socket from below.

Thanks again. Great explanation.

Scott
I hope a diagram isn't too much trouble! If so, don't worry about it!!!

Thanks for offering to do the diagram...

I was disapointed to hear the hum. I had thought one advantage of the electronic ballust was no audible hum. On the other hand, every box in the stack of fixtures had been opened and retaped shut. Maybe I ran into a lode of somebodys rejects.

Regards,

Charles

It took some time to figure out how create do a "publishable diagram". I used a combination of AutoCAD, Publisher, and Paint Shop Pro to do this. I had to learn new things about each software program and then looked upsome HTML codes to display them better. I was something I needed learn how to do anyhow. I hope this clarifies things.

The ballasts that I listed here are not the only ballasts that can be overdriven. These are just some of the common ones. If the ballast are electronic and are wired the same as these diagrams show, then they are probably overdriveable.

Remember, always make sure a ground wire is connected to the fixture! This is both for safety and it helps the lamps to start if the metal reflector is grounded.

Here are the DIAGRAMS:

With the clarity of the diagrams, I am pretty sure that I will be picking up a few items from HD, Wally-world, and possibly GrayBar.

Nice diagrams. Thanks Again!

David

Even though the electronic ballast is powering the lamps with a 22kHz or higher current, it is still being derived from 60Hz line current. The fact that it hums loud enough to annoy you is disappointing to those of us expecting very silent non-flickering power. Some ballasts are "noise" defective.

You might try to exchange it, claiming you bought it to use in a "extreme silence" situation. You might also check one thing. I bought 2 HD fixtures from one shipment which were slightly different, could not be overdriven, and had a greater than desired hum. On the "yellow wire" side of the ballast, there were only one yellow wire and one other colored wire (I forget which). Each wire went to one pin on one lamp. Then the remaining pins on each lamp were jumpered together. This was some kind of "series" wiring, not "parallel". I was bummed but I used them for my garage.

Wow. Great diagrams! You are a gentleman and a scholar. Funny thing. It cleared up my q's on the red and blue wires but raised a little tiny question on the yellow connections...I was at HD yesterday asking the employees if they knew how to do it. The first thing the guy said,"oh you don't want to do that, it will cut down on the life of your bulb..." I said, " I know but I will replace them next year anyway!"

The one follow on I have is I think my instant start sockets(or tombstones I've heard them called now) have the shorted pins like you said. They are weird looking with the holes in the bottom instead of the front like your diagrams. If you could lay the tombstone(or socket) flat, on the bottom(or what was the bottom) you'd have four holes. The top two holes look like they have wires inside that short the pins. I tried to buy add'l Litonia sockets but they only sold the kind that are in your diagram-with the holes facing you from the front(not underneath on the bottom like mine.) I wanted to take them apart to make sure.

On your diagrams you have the yellow wire jumping from one hole to the other on the socket(the OD) On my sockets, the holes are underneath, on each side -two to a side. If my socket is already shorted(I sound like I know what I am saying)is it ok to just put the yellow wire in one side of the socket? I think that is right. Isn't it? I suppose if nothing happens, then I can cut a little tiny wire to short the pins (talking about yellow here)..But...I think they are shorted sockets...

Come to think of it, if my blue and red wires have shorted pins inside the tombstone, should I connect them prior to putting in the hole so the wire only enters into one hole?

*I guess I need to know if the shorted pins make a difference in your diagram* and if so, would that change the wiring at the socket.

Thanks again. Feel fortunate to know you and have your help. Almost there I can feel it. I hope I don't burn you out! I am getting to the point where I am just going to try it anyway and if I kill a ballast then so be it.

Scott
I take full responsibility for my choices. Don't worry!

After reading the first few posts on this thread, I made a few overdriven four foot ballasts, and was pretty pleased with the results.

However, I'm most interested in the 2 ft. mod, (the same configuration as the normal overdriven ballast, but with two 17w 2 ft. t8's with a jumper wire in the middle, folded in half to make a nice short bright light. (which happens to be perfect for my 15 gal. planted fishtank).

Anyhow, here's my problem. When I run the overdriven fixture with the 4 ft t8's, it runs perfectly, for as long as I have it on. When I switch out to the 2 footers, (with the short soldered wire jumpering them), it runs flawlessly for about four minutes, and then begins to flicker. Actually, flicker is putting it mildly, it looks like a freaking strobe light.

Not wanting to burn my house down or anything, I decided to try another set of bulbs with a different ballast and different jumper connection....which acheived the exact same results. In fact, if I plug the two ballasts in at the same time, they begin to strobe at the same time, every time. Go back to the four footer...no problem at all.

Something wrong with my soldering job? I've re-read the original post several times, so I don't think I missed anything...but if anyone has any ideas, I'd love to hear them.

I'm thinking about just picking up a few of those curved 4 ft t8's, (which also fit on top of the tank), but then I can only use one ballast (without stacking- since the curve of the bulb is so wide) instead of two. (four two foot bulbs right next to each other).

Thanks,

-c-

Clifford,
I am glad you liked the results. What was the original ballast you used, and what was the other one you said you bought? Obviously that inspired you to try the dual 17-watters. I am not exactly sure what you did that is causing the strobing effect. It sounds like something is maxing out, then shutting down and re-starting. That may be driving something to the edge of failure, but maybe not. I haven't had that effect happen with any of my OD lights. I don't know what you soldered, but I never have soldered to a lamp pin. I connected the two 17w lamps with extra sockets from the fixtures - the ones I bought just for the cheap ballasts.

Since I am sure some folks would benefit from using the shorter lights in some overdriven configuration I will post a diagram showing EXACTLY how that works. I will have to wait until after Christmas to do so. I hope the details I did post cleared things up a bit.

If anyone wants to download those diagrams, "right click" in the Internet Explorer window, and select "Save Picture As...".

Those diagrams are great! I finally got a fixture w/11" wide refector that I like( a christmas gift from my wife I might ad). My current fixture only has a 6 3/4" reflector. The new fixture is a Lithonia 2 4 ft. bulb fixture. It comes with a magnetic Advance ballast which I will disgard. I like this fixture because it has a wide reflector like many of the older shop lights had. It has been hard to find one but my Home Depot got them in. I guess I'll search out those Sunparks you mentioned for overdriving unless you think there is a better one. Seems many of them are overdrivable. I will reread this thread for needed info. The diagrams are of great help. I'll let you know ASAP how things look afterwards.

It seems overdriving is a valid and growing way to get more light out of fluorescent bulbs.The TV and film industry has been doing it for some time now. So have the coral reef and fish people as well as pro studio photographers. My advice to anyone questioning it would be to try it out and see for yourself. The kinoflo lights are very expensive but I'm sure the internal workings are no big deal....just overdriven electronic ballasts. No reason we can't do the same on a cheaper level. I'd like to know what brand of ballast the kinoflos are using?

Cheers,
Mark

Mark

With this thread, I started to think that maybe I may be better off selling the present setup and converting to the "overdrive" ballasts. I could mount the fluorescents on a shelf setup. I would want to grow both seeds starts and houseplants and herbs (and possibly tomatoes). Iwant to keep the plant setup cheap but effective. Does anyone have any input on whether I should sell what I have and start over with the "overdrive" considering my requirements? Thanks

I haven't had that effect happen with any of my OD lights. I don't know what you soldered, but I never have soldered to a lamp pin. I connected the two 17w lamps with extra sockets from the fixtures - the ones I bought just for the cheap ballasts.

***************************************************

Thanks for the reply, now the lights are on in my head and things seem clearer. One more question, did you jumper 2 wires between the non-ballast-ends, or just one? (ie, the non-ballast-end sockets each have four holes on them (or two pairs of holes rather). Did you just jumper any hole from lamp-socket-one to any hole on lamp-socket-two, or did you jumper the right side of lamp-socket-one to the right side of lamp-socket-two, and the left side of lamp-socket-one to the left side of lamp-socket-two).

I suppose I'll just try both ways when I get home from work tonight. If my intensities look right, and I get no blinkies, I might be on the right track. ;)

Thanks again for the help.

-c-

I'll at least tell you this for now. By "non-ballast" side, I am sure you mean the connection between the two 24" lamps. The filaments on the "non-ballast" side of the lamps do not have any "pre-heat" function. They just conduct the current between lamps. For best results, just connect ALL 4 of the in-between lamp pins together in some fashion. My diagram will show you several workable variations.

You still seem to have a bit of trouble with the lamp socket holes. If there are 4 wire insert holes in your socket, then 2 of the wire-insert holes lead to one lamp pin, and the other 2 wire-insert holes lead to the other lamp pin. There is a very good reason to put 2 insert holes for each pin. That makes it easy to jumper the lamp pins when they need to be. This is exactly that type of situation. Jumper both pins on each of the "non-ballast" sockets, then connect the two sockets. This maximizes the electron flow between lamps.

ok, i just plugged it in. I am having trouble seeing if it is much brighter, if at all.

The one thing I didn't do was short the pins together at the yellows because I thought I might have internally shorted ones in the tombstone.

Would this make a difference? It is still bright and looks fine...Just not sure if it is much brighter.

Scott

Thanks for the reply posts, as it turned out, my jumpering was fine the whole time, I just had broken some of the white bulb clips when I originally pulled out and replaced the wires for overdriving purposes. All I had to do was crack open the backs of the clips, reseat the copper leads, and bingo, no more flashing. (amazing what a difference a solid electrical connection can make...next time maybe I'll check all my work before jumping to conclusions).

garden boy:

I think that really depends on the application. I'm mostly using my lights on fishtanks, reptile cages, and a couple of seedling trays. (palms, passion flowers, agaves, etc...will also be using them for starting heirloom tomatos, peppers, artichokes, etc in the next few weeks...short outdoor season in western new york). In my opinion these overdriven ballasts are an *excellent* replacement for the "commercial security lights" many people are currently using for their seedlings, like the 65w compact flourescent from Lights of America. I have three (two on fishtanks, and one on a seedling tray), and I think my 2 foot overdriven setups are every bit as bright and effective (in fact maybe more effective, because I get a better spread of light) as those. As a bonus, the new setups only cost $11 each instead of $30, are a better quality than the LOA (I've had several die on me) and apparently use 54 watts instead of 65. Pretty nice.

The difference is spread and intensity. You can definately grow small houseplants and herbs with these ballasts, but if you want to match the growth you'll get under your MH, you'll have to litterally have them growing *right* underneath the lights. I would keep them practically touching. A 400w MH with the right reflector should give you at least a 3'x3' spread, maybe more, with great penetration through the folliage. The flourescents won't do that (at least, not nearly as well). For instance I have a wide veriety of low-light houseplants in my area here at work. Where I sit there is zero natural light, but the ceiling is covered with 4 ft. 3-bulb flouresent fixtures. The plants survive just fine, they even grow a little bit...but with 4 feet between most of the plants and the lights, if I was trying to keep my kitchen in stock with mint, basil or thyme, it wouldn't even come close to cutting it. If you decide to switch, I would construct some kind of enclosed shelf or wrap-around reflector, so you can maximize the light your plants get. Also, if you're trying to take the tomatos full term (as you probably could with the MH and HPs), I don't think they'll do very well.

doviende:

As far as I can tell it's the same, and they seem equally intense (plus you don't risk breaking clips like I did). I'm not positive if the ballast "sees" the load differently (being that with the original wiring it's using "half" of itself to overdrive each bulb, whereas in the od configuration it's using the "whole thing" for both bulbs)...so your mileage may vary.

Thanks again for the help Zink, nice to find someone patient on an internet forum...

-c-

Forgot to mention bulb pricing, you mentioned they were expensive, but didn't say what kind of pricing you were finding. You should be able to get 400w MH bulbs for around $20 if you shop at the right spots. Some specialty bulbs I've seen are as high as $70 or $80...but who wants to spend that much...heck, you can buy a while refurbished 400w remote ballast system on e-bay with a brand new bulb for around $100.

Just thought I'd mention it. I do my bulb shopping at graingers or greybar (both of which have online catologes if you have a business license/tax id), but you could probably find them at Home Depot, Lowes, or online for similar prices.

-c-

here is a picture of the socket in my lithonia fixture. I had to wade through their site...still was not able to find if it was internally shorted or not.

I guess I can short it on the outside and see what happens(the yellow wires)

thanks,

Scott

It has been almost a month since I heard hide or hare from you. Possibly you will never see this, but for posterity(and to end this thread on an even 50)... I wanted to post that tonight I shorted the two yellow pins and *BAM* it worked! The answer with my Lithonia is that the tombstone/sockets are not internally shorted. When I connected the yellow sockets with a tiny little yellow wire, it lit up like the sun!

I used my hydrofarm light meter and we decided that they were now 50-60% brighter! Pretty kewl. Thanks again wherever you may be.

Scott
someone now feeling a bit less new

TomG. - aka Plant_Guy

Actually, it’s been only two weeks, unless my portion of the planet rotates slower. Sorry, but I have been keeping quiet, waiting, waiting, quietly waiting for you to announce that you finally jumpered those damned pins together. Just kidding!

I have been taking care of other things and haven’t gotten around to posting any more overdrive information. I am glad to hear that you did get the lights really aglowin’. I did check out the Lithonia socket link but there was no way I could tell what was inside of it. I thought I had posted a reply to tell you to just go ahead and jumper them together to be sure, but I see now that I didn’t reply. Sorry about that, but you got the deed done anyhow!

I saw in another post that you had bought some kind of meter. Once you get the hang of taking some measurements, you will be able to track down and solve a lot of problems. I highly recommend learning just a little bit about voltage (AC and DC), current and resistance, and how to measure them. You can buy some very basic, easy to understand books, that cover a few simple concepts which will broaden your abilities considerably. You really don’t need to learn too much to be able to take highly relevant readings of your projects.

Once, a friend of mine had a VERY long speaker wire, running through several rooms, heavily stapled to his baseboards, door frames etc. It had a short somewhere. I disconnected the wire at the stereo and the speaker, then measured the resistance (through the short) at each end of the wire. I then measured the wire length – while it was still stapled to the wall. I took the ratio of the wire resistances I measured, multiplied it by the length of the wire, and BULLSEYE! Exactly at the calculated distance was one bad staple – it was puncturing and shorting the wire.

Did you at least get the results you were hoping for with the lights?

Farmer Paul,

Years ago, in the 80’s, I used to build my own DC power supplies. If I recall correctly, I WAS able to parallel DC power supplies. They were NOT “switching” power supplies, which may be the difference here. As I remember, one power supply usually would have a bit more voltage output than the other. Only if the load pulled the voltage down to the threshold of the lower power supply would the second one begin to supply current to the circuit.

It really was like paralleling two batteries to double the available current. If you wire a bunch of auto headlamps to a stand-alone 12v car battery, they will light and begin to draw current. If you parallel the battery with another, the headlamps will brighten AND the current load on both batteries becomes less. That is the best analogy I can come up with. Also, the 2x overdriven ballast actually draws less current (verified by measurement) than if it were lighting two bulbs, instead of one overdriven one.

Zink

I was suffering from new person paranoia, I must admit. When you think you ask too many questions and burn the expert out(aka high maintenence newbie sickness, pain in the arse asker, etc.)

I finally had a friend come over and he said it wouldn't hurt to short the pins together, and that is probably why to that point, I had only normal brightness.

Yes! Absolutely. Thank you very very very much. They are so bright, it is very obvious. There is a little hum in the ballasts, but I assume that is normal and just because of the extra voltage/current..

I am probably going to upgrade each fixture now over the next year as I get the money and time..Another reason for the delay-wife, renter and dog that are trusting me not to do something stupid...Had to be overly cautious...

Thanks again. I appreciate the time you took to make the drawings and answer q's.

Scott

Yes, the Magnetics have that too. The “3-wire setup” you mentioned is usually on the side of a ballast which shares a common wire (the yellow one) for the “pre-heat” starting function of a Rapid Start ballast (2-lamp). I do not know if there is any sort of industry-wide standard, but this color coding is typical of all the Electronic and Magnetic ballast diagrams that I have seen.

On a 4-lamp Rapid Start ballast, there are double the number of wires (2 red/2 blue/2 yellow). Both yellow wires are actually connected to the same common point inside the ballast, or at least they behave that way.

For an Instant Start (2-lamp) version , that “common” side of the ballast always seems to have a single shared red wire.

On a 4-lamp Instant Start ballast, the “common” side usually has 2 yellow wires, each shared by a pair of bulbs.

Sometimes, on a 2-lamp Rapid Start ballast, there will be ONLY 2 wires on that side. This kind of ballast can’t be overdriven. The current flows through one wire, then through the filament of the first lamp, then through a jumper wire to other lamp filament, then back to the ballast via the second wire. If one lamp fails, both will go out.

Since you are discussing Magnetic ballasts, I need to emphasize that rewiring to overdrive is NOT possible with a Magnetic ballast. You may already know that, but I’ve gotta mention it anyway. You would regret the results.

I also want to mention that I used the term “pre-heat” because that is what the filaments in a Rapid Start ballast are doing. Officially though, there are ballasts which are called Pre-heat ballasts. They are in the fixtures that use an extra starter device and are only found in Magnetic ballasts, usually the lower-wattage ones.

Scott,

You have every reason to be paranoid. I just recently saw satellite photos of your lawn furniture posted on a National Security Bulletin. Just kidding.

The hum you are hearing shouldn’t be from EXTRA ballast current or voltage. The reason is this:
A NORMAL electronic ballast with 2 lamps(32wT8) uses about 530 mA of line current [63.6w]
An OVERDRIVEN electronic ballast with 1 lamp(32wT8) uses about 460 mA of line current [55.2w]
The two individual lamp circuits inside the ballast are sharing the lamp load. I measured them several times.

Just an hour ago I was listening to a hum coming from one of my non-overdriven electronic ballast fixtures. Some of them just hum more than others.

Zink

I just completed my first overdriven Home Depot fixture thanks to your helpful diagrams and the explanations and photographs given in this message thread. I put it on a table beside a normally driven version of the fixture for a comparison and turned them on.

At first one bulb of the overdriven fixture was nicely brighter but the other was bright at one end and the rest of that bulb had what looked like some kind of rocket exhaust standing waves moving around in it.

I wondered if it mattered which end of the bulb was installed in which end of the fixture, so I reversed the ends of the faltering bulb with no big improvement. Then, suspecting a "weak" ballast (or a ballast whose wiring I had done a "weak" job of connecting) I interchanged the bright bulb and the weak bulb, keeping their ends in the same orientation. I expected that the faltering bulb would work fine on the other side of the fixture and the previously bright bulb would have problems when moved, indicating that I would need to improve my connections on the problem side.

But voila! Both bulbs were brilliantly lit and obviously way brighter than the standard fixture. Very satisfactory. The concept is proved, so I have purchased additional fixtures to bring my total number of fixtures to 16. I may not use them all for overdriving, but I will be making a fluorescent plant stand that is mostly if not all overdriven.

I remain curious about my experience "futzing" with the overdriven fixture to get it to light nicely. Does it matter which way you install a bulb? Do I need to solder my connections? Is there resistance on the bulb prongs that needs to be removed by some kind of cleaning/polishing? I plan to repeat this side-by-side table test on each new fixture that I assemble.

I would like to express my heartfelt gratitude for the information and expertise you and others have shared in this remarkable message thread.

-- Burton --

First I want to say how absolutely thrilled I am to have found Zink and his wonderful research. He truly is a godsend to me, who living indoors and raising Bonsai, have always faced adequate lighting challenges. I only "found" this forum this morning and I have read every post and practically have the red/blue, blue/red, jumpered yellow stuck wiring explanations running through my mind.


This morning I logged into HomeDepot.com and I backordered the fixtures, then I proceeded to visit each Home Depot in my area to see their selection and in hopes to find a spare SL15. Alas, my searching went in vain. I finally asked one, especially attentive attendant ;-) to do a little research for me and to check the inventory of all the Home Depot in his computer inventory. He informed me that NO Home depot, in Cali at least, has them in stock or is expecting them. I felt a little disheartened to have heard this (the hope dashing upon rocks syndrome thing). I informed the young man that the website stated that they would be shipping from the online store on the 15th of Jan. (just a few days from now). He told me that it had been his experience that the fixtures were more than likely going to be discontinued and the online backorders would be offered a similar replacement. He said that the original stock of these fixtures may have been a home store purchase of some surplus stock, which is why the special low price and the variations in availability.


Zink, I wonder if you may be able to steer me to another comparible model with the similar wiring method? I sincerely do appreciate all you have given to this thread.


Bonsaika Z18(SS) Calif.

I am glad to hear you succeeded in your efforts. I have no idea what the trouble was when you first tried out your rewired light. Know what? I have had that happen to me a dozen times. The fixture will seem to have a problem, I’ll mess around with the bulb, then suddenly it works!

I suspect it is just that something is not seated correctly and doesn’t fully light until it is jostled into place. Who knows. I never figured it out. Often, when it is cold and/or the bulb is new, there is a swirling at the ends of the bulb, until the bulb warms up. Cool lookin’ effect.

I shouldn’t matter which end of the bulb is which. You don’t need to solder any connections, unless that is the only way to get your wires to contact. Usually, the voltage present is high enough to overcome a “dirty” connection. If the current is not flowing, the voltage at the bulb ends rise as if it is going to re-start or re-ionize the bulb.

The filament inside the lamp has a small resistance (between the two lamp pins) because it provides a heating function on startup ONLY if you are using a Rapid Start ballast.

Basically, if the fixture I am messing with doesn’t light, I check my wiring first and then jiggle the connections. That usually works.

Bonsaika,

Thanks for the kind words. I do not know what ballasts are in other brands of shoplights, but if they are electronic, they are likely to be overdriveable. In the diagrams posted above, I list several ballasts that are commonly available and will work. I have found that the wire color-coding I showed is very common. Look for the wiring diagram, usually found on the top of the ballast, and match it to the rewire method in my diagrams above.

If it is a Rapid Start ballast AND there are only 2 wires running from the ballast to one end of the fixture (one going to each socket with a jumper between sockets), then it is NOT overdriveable. The lights operate in series and cannot be paralleled. But, as my experience goes, this is uncommon.

I do know that the better brands (Advance, Sylvania, Magnatek, Universal, GE) seem to work very well. The Sunpark SL15 ballast, found in the Commercial Electric fixture, has worked for a LOT of different bulb types I have tried, not just the 32watter’s.

Zink

I wouldn't be surprised if the sats were trained on me. If my visits to the hydro store and here haven't gotten phone bugged, house photoed from space, and helicopter infrared fly overs, then I would be surprised!!

Back when I had my greenhouse(thought I'd never have to know about lights, ever...) We had regular heli fly overs. My neighbors always joked with me about it.

I went to Home Depot today with my new found boldness. I am teaching the guys there what you taught me. Of course, should anything happen, I have have no idea who zink is!! NOt to worry...lol I needed to buy more wire. They didn't have the exact gauge of wire, but the guy said if it was bigger I'd be ok.

Wondering why I just bought a 1000 watter now!! I guess I have money to burn..........NOT! :)

thanks again,

Scott

"You don’t need to solder any connections, unless that is the only way to get your wires to contact. Usually, the voltage present is high enough to overcome a “dirty” connection."

Thanks for the reassurance. I will continue on using the twist-on caps or crimp caps I have been using.

"I have no idea what the trouble was when you first tried out your rewired light. Know what? I have had that happen to me a dozen times. The fixture will seem to have a problem, I’ll mess around with the bulb, then suddenly it works!"

That's good to know. I will continue to use that technique. Thanks again.

-- Burton --

I used my infrared pyrometer and measure the heat from the regular fluor bulbs and compared it with the heat coming off the lights of the overdriven fluorescents.

The regular lights inflos-4 foot T8's-were 100F, while the overdriven ones were burning at 120F.

Scott

I have thought about changing to "grow-lamps" and have visited a lot of sites, but am not fully aware of the benefits, and still am a little confused. BUT, when I read this thread, I was convinced that at least SOME growers are serious about their lighting. You all have at least taken a scientific approach to all this, but maybe to a few degrees more than I need to do.

I am convinced that I will, indeed, switch to either gro-lux or Phillips bulbs. I only need about 24 sq ft of lighted space, and am currently using three fixtures, with two bulbs each. I may expand to 4 fixtures.

I plan, therefore to purchase gro lux, or phillips bulbs, and just replace the current "ordinary" fluorescent bulbs with the new ones. If I expand to 4 fixtures, one of them will be the Home Depot fixture.

I know nothing about electricity, or ballasts, or wires, or quantum physics, or anything even close.

My first question is: will the bulbs you are recommending, work in my current fixtures, which use just the common "work-bench-fluorescent-bulbs"?

My second question is: If I need to purchase the recommended Home Depot fixtures, ok, I will do that, and then purchase the bulbs.

My third question is: and please forgive the naivity of my question....but, what is the real advantage of "overdriving" these bulbs, other than just getting more "brightness". I am assuming that the gro-lux or phillips bulbs are engineered and designed for plant growth, and don't understand why more brightness is necessarily "good". I realize that there is some economic benefit also, but it is worth the effort, and is it possible that these improvements are something that you all are doing primarily to learn more about the potential of the various combinations?

I have read every reply to your post and am impressed with the detail to which all of you have worked this issue, both currently and, apparently in the past, and will serioiusly consider your opinions. I am growing the common things, tomatoes, peppers, okra, basil, eggplant, cabbage, kale, cucumbers, and annual flowers like zinnia, statice, etc.

In your opinions, will I get better seedling and plant growth with the "overdriving" effects than with just a change to the gro-lux or phillips bulbs, or is it just too much of a guess to go out on limb?

By "better growth", I mean more compact, and sturdier seedlings and plants, and less ganglier than I am getting with just the household bulbs. I do believe that I will get better plants by switching to the gro lux or phillips, but I am wondering how much more gain I might be expected to get with the "overdriving"

Thanks for any help or comments

Good Growing, and Good Lighting, to all of you

Welcome to these forums. I am new here too. I am certainly no expert, but I feel I have benefited greatly from the knowledge that has been shared in these forums and in this message thread particularly. All told, I have purchased 28 of the Home Depot "Commercial Electric ShopLights" for use in constructing two plant starting stands. Most of these will be used to produce overdriven fixtures according to the instructions given in this message thread.

So I far I have made three successful conversions and a fourth is nearly complete. I have to cut notches out of its reflector to make it fit within the pillars of our metal shelves. I will be using a mix of cool white bulbs and warm white bulbs, all 4-foot T8s. The overdriven fixtures are very noticeably brighter and somewhat warmer on the bulb, but hopefully not harmfully warmer on the plants.

I have a starter flat soaking right now to plant three varieties of onions and some frilly semi-double pansies. That should happen tomorrow. I think both of those need a lot of extra development time before setting them out here in central Maine.

I would use some "Gro Lites" T8s if I could find them economically. I purchased a 10-pak of cool white Philips T8s at Home Depot for $19.97 but unfortunately they don't have warm white T8s. I have found a local electric supply place with warm white T8s for about $2.67 each. I wouldn't want to pay much more than that for Gro Lite T8s, so I probably won't find any for "my price". I am not convinced that Gro Lites are worth the extra cost, but if I did get some, I would probably overdrive them.

"...but, what is the real advantage of "overdriving" these bulbs, other than just getting more "brightness". I am assuming that the gro-lux or phillips bulbs are engineered and designed for plant growth, and don't understand why more brightness is necessarily "good"."

Most plants don't get enough light under fluorescents. So I think your plants would be better off under the brighter light of overdriven fluorescents. The normally driven T8s I have seem brighter than the normally driven T12s, but that may be some kind of optical illusion. I don't have a light meter here (mine is in storage with a lot of other stuff we haven't moved yet back in St. Louis), so I can't make foot candle measurements.

I think many plants need many more foot candles of light for sustained growth than they will get from under any fluorescent fixture, overdriven or not. You might want to do a search, on the Internet and in bookstores, for the light requirements in foot candles of the plants you intend to start under lights.

Fortunately plants can do well enough to get to transplanting size under less light than they would require for sustained growth to maturity.

"However, the seedlings always get a little gangly, and so every year I find myself carrying them outside on warm days, and back in at night from about mid february until about the first week in May, to get them some "real" light."

A big problem with seed starting is that after they have germinated and got their first true leaves they need a cooler temperature than most houses are kept at. For stocky sturdy transplants you should grow them at 50 F to maybe 65 F tops. Growing them warmer makes them spindly. If you had a cool basement or some other room that didn't require human habitation, you would probably be better off putting your fluorescent plant growing fixtures in there. I plan to use our breezeway, because it is unheated except for the heat that "leaks" to it through our double-wide glass door. It isn't a true breezeway because it is closed to the outside by a door on each end and it has lateral doors to the garage on one side and to our basement "in-law suite" on the other.

Our outside temperatures have been ranging from zero to maybe 20 while the breezeway temperature stays at about 32. I will have to raise that by maybe 25 F to make it habitable for seedlings. I am hoping that the fluorescent lights themselves will provide some heat source. I may try to add some insulation (it's uninsulated) and possibly a thermostat-controlled electric heater to keep the temperature above 50 F. You might want to think how you can make it cooler for your seedlings. Chances are that when you took them outside they not only got more light, but cooler surroundings as well.

Incidentally, seedlings develop stronger stems if they are exposed to some wind. Some people use a small electric fan to provide that "wind". I plan to put a small fan on a timer for our seedlings. Last year we had a problem with seedlings becoming spindly and I hope to correct that this year.

-- Burton --

"The regular lights inflos-4 foot T8's-were 100F, while the overdriven ones were burning at 120F."

Thanks for sharing that info. Many of us don't have an infrared pyrometer. (grin)

-- Burton --

I have definitely been curious to know the temperature of some of my lights. Fluorescent lamps do have a temperature curve for optimum brightness. I have always thought that most bulbs seem to burn a lot hotter than what is recommended. Since the cold weather set in, I noticed that a couple of compact fluorescents in my garage are a lot brighter than they were before. They still get warm, but definitely burn brighter.

One of the effects of overdriving is that the bulbs do get hotter. In spite of that, the light output is definitely increased. I originally found the overdriving technique in the fish/coral forums. Those folks like to overdrive by 4X to achieve maximum brilliance. I tried that, but they got too hot for my taste. Burning at 2x is more efficient.

Since I read your post tonight, I took an overdriven Philips PL-L 40watt fixture out to my garage (currently 35ºF) and plugged it in. When it warmed up, it was brighter than it was in the house. I then took it out to my back porch, (currently 16ºF) and plugged it in. It got dimmer as it adjusted to the cold. Just like the temp curve said.

By the way, the new High Output T5 lamps are designed differently, with the temperature curve about 20ºF higher than the rest.

Jeb,

The really great advantage of electronic ballasts over magnetic ones is that the circuitry uses feedback to regulate the current going through the bulb. That particular ballast will operate a range of bulbs, as indicated both on the ballast and the specification sheets - which I downloaded. The lamps that happen to fit that 4’ fixture are the 40wT12, 32wT8, 34wT12 and 25wT12 – all of them 48”. I don’t even know of any other lamps that would fit that fixture. Whether overdriving or not, the 32wT8 will be the brightest, the 40wT12 will be a bit dimmer, and the 34w T12 and 25wT12 will be a disappointment. I compared them with a light meter to be sure.

The 34wT12 “watt-miser” bulb, developed over a decade ago, was a joke. It used less energy - but gave off even less light! To achieve the same light levels took MORE energy! Really stupid!

Believe it or not, I took some 40wT12 bulbs that would no longer light up in a mag-ballast fixture, put them in an overdriven HD shoplight, and voila! – they really lit up. The electronic ballasts have no trouble with the 40watters. The old, magnetic ballasts, however, will not light up a 32wT8. Who cares,… we’ve got e-ballasts now.

I, personally, do not know what you would do to create a fire hazard if you mount the bulbs properly. I have tested the SL-15 ballast, as you can read somewhere else here in these posts, on an impressive variety of lamps. Most everything worked quite successfully, and were certainly no fire hazard to me. It’s just a “cover-your-ass” disclaimer.

THE best 40wT12 to use in an overdriven fixture is the Sylvania Gro-Lux Standard bulb. As I have come to find out, the Gro-Lux Standard (not the Wide Spectrum) has the best formulated phosphor coatings of any 40w grow lamp. It has a low lumen output, but ALL OF IT concentrated in the proper wavelengths, actually giving off more, better light.

SeedStarterABC,

The reason that common light fixtures are not overdriven is because the efficiencies of general purpose lighting were mandated by the Energy Act of 1992, to meet certain energy use specifications. That was a really good legislative act that resulted in improved general-use lighting.

The reason for overdriving (only recently possible) is to get more light out of a fixture - for special purposes such as growing plants. There are some ballast manufacturers (Fullham, Icecap, Workhorse) that cater to these specialties. Their ballasts can overdrive a variety of lamps, and are sold for that purpose. The official term for more light from ballast is “high ballast factor”.

The nice result of that energy legislation is that the 32wT8 lamps, with an electronic ballast, now put out more light, more efficiently, than 40wT12 fixtures used to. You can get really good light just using a non-modified e-ballast shoplight and T8’s. However, “overdriving”, as I described above, will get you 70% more light per bulb.

No matter what, if you buy a shoplight with an electronic ballast, you will be able to use 32w or 40w lamps. Just don’t use 34wT12’s or 25wT12’s. If you bought shoplights that require them (so-called energy savers), buy new fixtures (plant savers).

Bbled,

Yes, you will get more light using 4 bulbs in normal fixtures than using 2 bulbs in overdriven fixtures. The idea of overdriving is to maximize the light per fixture, usually because of limited space or “high-light” loving plants. Or just because it’s so damned cool once you see it. Overdriving the seemingly dim Gro-Lux Standard bulbs is rewarding. They aren’t dim anymore!

Zink

The testers took several machines operating at normal speed, started running a processor-intensive game, and then removed the heat sinks to see what would happen. The AMD chips went belly-up really fast. The lesson there: Definitely secure your heat sinks and fans.

Here is the difference in comparing "overdriving" CPUs and ballasts.
>>CPUs
Every time the chip manufacturers upgrade their process, almost all of the new chips are immediately capable of running at a much higher speeds. Intel and AMD purposefully cripple some of the chips (clock-multiplier locking) and give them a lower mHz rating. As nuts as it may seem, this is done for marketing purposes to maintain an array of CPU speeds to sell. Tech savvy folks who know about this trick can determine the actual potential speeds, and run the CPU closer to the processor's true limit. Some brave geeks will construct elaborate heat sinks and try to go beyond the max.
>>Ballasts
When you re-arrange the wiring to overdrive a ballast, you are sharing the "lamp load" between the individual lamp circuits. The ballast itself is actually UNDERDRIVEN, since it is now sending LESS total current to a single lamp than it would normally be sending to two lamps. It is the lamp that gets OVERDRIVEN. The ballast is running cooler, the bulb running hotter. This does not burn out the bulb, although it's life is shortened a bit. This is quite acceptable for the special purpose it is done for - obtaining more intense light for your plants.

By the way, all of my CPU overdrives involved finding out my peak stable speed, then dropping back a few mHz's. It is very safe - as long as you keep your heat sink attached. NONE of my CPU's ever fried!

Unfortunately, I did have plans to build my next computer with an overdriven AMD chip. Thanks for the video info. I do gotta be REAL careful now.

Zink

I just fixed up two Commercial Electric Shoplights to your
specifications. Thanks to the photos and diagrams the wiring part was a
real breeze. They really look bright.

The punched out triangular tab, that holds one balast can easily hold two
side by side after drilling four more little holes to screw them down and
new big hole on the side of the channel for the power cord.

That screw they use as a ground post is really tough. I had to use Liquid
Wrench, a lighter and a power drill to get it free. Generally I avoid
using a power drill in a situation where the vibration could affect
electronic circuitry.

The sheet metal screws that are included to attach the reflector to the
channel are no good. I used the kind for metal computer cases.

I don't see why I can't bolt two overdriven shoplight channels together
side-by-side, wire them in parallel to a single power cord and cut one
side off of two reflectors and end up with an overdriven four-lamp fixture.

Does this sound OK?

An aside on overclocking: A couple of years ago I had a tweakable
computer in a top-floor, un-airconditioned Manhattan tenement apartment
right under a black tar roof. In July and August, the overheating alarm
went off, so I opened the case, looked into extra fans and discovered the
world of overclocking. I put two extra fans in and was able to clock it
up a bit.

The best example of watercooling I saw was a guy in Malaysia running his
water jacket tubes through his aquarium.

If you would care to e-mail me, I could tell you about an experiment I
did with a computer and a small fluorescent tube.

"I don't see why I can't bolt two overdriven shoplight channels together
side-by-side, wire them in parallel to a single power cord and cut one side off of two reflectors and end up with an overdriven four-lamp fixture. Does this sound OK?"

Of course I, too, am waiting until Zink weighs in on this, but it sounds OK to me. I have already trimmed the corners of some reflectors to make them fit inside the vertical round supports of chromed wire shelves. I used a 32-tooth hacksaw, which was rather slow and noisy. How would you cut off the reflector portions? Sheet metal cutters? Nibblers? My problem with sheet metal cutters is that I always have a righthand cutter and frequently find myself in a situation where I need a lefthand cutter. I suppose I should get both. Nibblers have the advantage of not being righthanded or lefthanded, but I wonder if they could handle these mild steel reflectors.

I think Zink uses a Dremel tool. Gotta get me one of those. I like the deals Amazon.com has, and the "digital" model looks like the one for me. Some websites made it seem that many of the Dremel accessories (drill press, router, router/shaper, etc.) would not be compatible with the digital model, but Amazon seems to have more up-to-date information with respect to that.

Do you have any special technique in mind for getting nice straight cuts on the reflectors? Would you finish the raw edge to smooth it and possibly paint it with some kind of white enamel? Do you plan to cut down in the "bottom" of the groove or do you have in mind a better place or better way to make the cut? Industrial can opener? (grin)

Incidentally, there are two grooved sections on each side of a reflector in which you can cut, but I have learned the hard way (did the first one wrong) to use the outer groove, because the inner groove is needed to fit with the "body" section of the fixture. Good thing I have several "left over" reflectors. (grin)

-- Burton --

Has anyone found a cheap (i.e. <$10) two bulb fixture with and electronic ballast? I wish I had Zink's luck!

"Has anyone found a cheap (i.e. <$10) two bulb fixture with an electronic ballast? I wish I had Zink's luck!"

The Home Depot here in Augusta, Maine has them and has had them for several months. They sell a lot of them. I have bought three batches of them, for a present total of 28, and I will probably buy some more. So far I have made four conversions, all successful. HD's price for the fixtures has risen to $7.98, possibly because of the demand for overdriveable fixtures.

-- Burton --

I am hoping that the fluorescent lights themselves will provide some heat source.

Believe me, if you have enough of them, especially if they're overdriven, you won't have much problem keeping the area warm, assuming it's not terribly large.

Last winter, I started plants in the basement, using a total of 8 48" fixtures (not overdriven), with 40W lamps. The fixtures caused the 15'x15' room to become noticeably warmer. So much so that from mid-February on, I didn't have to run a space heater in the room, which I usually do.

Jason

"Believe me, if you have enough of them, especially if they're overdriven, you won't have much problem keeping the area warm, assuming it's not terribly large."

That's encouraging to hear. The breezeway isn't very large; it is about 22' x 6' 4" but it isn't insulated, and one side has an exterior wall. We do plan to insulate it, so the lights may very well supply much of the heat needed.

My primary concern is during the dark cycle at night when the timer(s) have the lights turned off, when the temperature may drop too low. We'll provide an electric heater for sure, and maybe an alarm if the temperature goes significantly below the temperature the electric heater is trying to maintain.

-- Burton --

"Just went to HD and Walmart and purchased one each of their cheapest 2 bulb, 48" shoplights. Neither had an electronic ballast."

Since your local Home Depot does not stock the particular fixture that Zink recommends, you might want to buy it online here at this link to Home Depot:

Home Depot

I tried inserting a direct link to the specific product, but the link always contains a session ID that expires after a few minutes, so I will describe how you can find the product online for yourself.

You don't need to register at Home Depot just yet. At the upper left of the Home Depot home screen, click on "SHOP" and go down and click "Lighting and Fans". Under the Lighting & Fans links, choose Fluorescent Lighting. On the Fluorescent Lighting page you may see the Commercial Electric 4 Ft Shop Light featured at the top right of the page as a kind of "special" and, if it is, you can click on the orange title to open the product info page. If it is not currently featured here, click on the "Troffers, Strips, Shop Lights" link to bring up the first 10 of about 25 products with a default sorting of "Highest Price" first. Change the sorting to "Lowest Price", which brings the $7.25 Commercial Electric 4 Ft Shop Light to the top of the list. Click on its orange text to open the page showing full product information for it, as follows:

Commercial Electric
4 Ft. Shop Light
Model HBSL-15

Shop light fluorescent lighting will save up to $35.00 in energy* costs (*Based on 11c/kilowatt hr., 4hr/day over the life of the product as compared with a magnetic ballast). Energy-saving, uses 75% less energy than an incandescent. Longer lasting, lasts up to 20 times longer than an incandescent. Ideal for use in basements, work areas, laundry rooms, recreational areas, attics and more. Extra long 5 ft. power cord. Instant-on electronic ballast. Uses two 48 in. fluorescent tubes (not included).

Internet/Catalog # 162474
Store SKU# 140904
Price: $7.25/ea

The online price is only $7.25. I am paying $7.98 at our local Home Depot. That difference in pricing might help to pay for the shipping. The model number and Store SKU number 140-904 agree exactly with the boxes I have been purchasing, but there is a small chance that these might be like the one sample that Zink purchased that weren't overdriveable. I don't know for sure, but I think you could return an online Home Depot purchase at your local Home Depot if you needed to. You would need to bring your paperwork. But I would be very surprised if these aren't the "genuine article" capable of being overdriven.

-- Burton --

Thanks for the help. I have already been online at HD and ordered 6 of the fixtures. With shipping, they come out to about $9.00 each. Not bad considering the magnetic ballast ones in the local stores are $8.50.

Earlier in the thread someone said that HD.com was out of stock of the HBSL-15 models and was substituting another brand. I hope this is not the case. Keeping my fingers crossed.

My tool of choice for these customizations has definitely been my Dremel! My wife bought me a Dremel set for Christmas several years ago, per my request. When I started playing with it, I was so thrilled I went out and bought every accessory I thought I might use. What a tool! I do recommend the variable speed model, if anyone does buy one. Don’t forget to buy a pair of safety glasses too! Never Dremel without them! Also, don’t EVER solder circuit boards without pants on. Although these shoplight alterations don’t require soldering, this is a very good warning. Been there, and won’t ever do it again.

One thing that would be a tedious job with the Dremel is cutting a metal reflector along it’s length. Hardy-t was going to cut one edge off and combine reflectors. The Dremel is perfect for small cuts, but I would want to use a bandsaw for a longer cut like that. I have done all kinds of different alterations to these fixtures - cutting them in half, combining reflectors, and mounting the ballasts in different fixtures. I would keep on the lookout for people discarding fixtures. I have used reflectors from other people’s dead fixtures. Repaint them with a glossy white enamel/laquer/whatever and they are good as new again.

Hardy-t, I would like to hear how the customization went. Many years ago I removed some 4-lamp fixtures from a condemned building. I added another ballast to some of them and made 6-lamp fixtures. A year ago, I removed the old magnetic ballasts from one fixture and put in overdriven electronic ballasts instead – some of them were the Home Depot shoplight ballasts. The ballasts were a tight fit, but the fixture is almost too bright to look at!

Since the subject of heat has been brought up here, I should point out that it is the bulbs themselves that run hotter, not the ballast. Several overdriven bulbs in one fixture might put out a bit more heat than normal, but not anywhere as much as an HID lamp.

I have been reading in these posts that many Home Depots do not have the good overdriveable fixtures in stock. They seem to always be in stock here locally, although the price has ranged from $6.25 to $7.99. I have no idea why.

For those considering buying the Home Depot Commercial Electric Shoplight 140-904 (grey box), I want to post this:

- - - - - CONSUMER ALERT!! - - - - -
Home Depot sometimes ships a load of these shoplights with the WRONG type of electronic ballast for overdriving. The ballasts look the same, but do not have a label, and have only two wires (a red and a yellow) going to one end of the fixture. The correct ballast has a label on it and 3 wires (a red, blue and yellow) going to that side of the fixture. Both ballast types have 2 red and 2 blue wires going to the other side of the fixture. (As you may know, I am ignoring the black and white power supply wires here). I recently stopped by my Home Depot and they had another pallet of the WRONG fixtures for overdriving, again. I would open up a box before purchasing, just to see if it has a label on the ballast.
- - - - - CONSUMER ALERT!! - - - - -

I did purchase a couple of the wrong ballasts a while back. Last night, I tried to wire one of those weird “unlabeled” ballasts in an alternate configuration that I had used successfully on another ballast. It didn’t work and I fried the ballast. The other ballast rewire I was trying to mimic was an Advance REL-2S110 ballast, which was not really overdriveable. It is designed to operate 2-T12/HO lamps, from size F48/60w to F96/110w. I was able to wire it to drive 3 or 4 bulbs, both F48/60w and F32’s. They lit up, but only the F32’s were using a little more current than normal, and were a little brighter than normal. I tried that same successful wiring scheme on the HD “wrong” ballast and it died.

For those who may be interested, I purchased a GE 2D 55watt “torchiere” bulb the other night. I hooked it to an overdriven SL-15 ballast and it worked just fine. It was drawing .39A of current. I looked up a ballast designed for the 2D/55w, and it listed .45A of current to attain a ballast factor of 90%. I would like to have attained a better current draw on that one. I have used the SL-15 to power 54watt T5/HO lamps to exact current specifications, for a full 100% ballast factor.

Zink

seedseller1

Zink

I think there is a chance that SeedSeller's dental pick technique could work well. I have been using a twist-while-pulling technique that has worked every time, including the first time, but on occasions I have gotten too agressive and broken off a short piece of the solid copper wire in the socket. That concerned me that the loose piece of bare copper wire might bounce around and short something, so I removed the back from a spare socket to see what I was up against. (I broke the back piece in the process but I think, with the right technique, it could be removed and replaced without damage.)

First, I saw that the small loose piece of wire was confined and not in danger of causing a short.

Second, I saw how the socket "worked" with the solid wire being inserted in through an undersized gap pushing up against an inward slanted piece that lets it in, but tends to jam into the wire to prevent its extraction (and makes a good electrical contact with the bare wire.) That explained how my "unscrewing back and forth while pulling" technique worked and why it left all those fine "screw threads" on the extracted wire and why, if you pulled too hard, you could cut/break off the remaining part of the wire.

Unfortunately I don't have a dental pick or anything equivalent. But I think it would be desirable to extract the wires without damaging them or the socket, because you are committed to reuse some of the sockets. The only damage I have done to a socket is to leave a short broken-off piece of copper wire loose inside, but captured in a cavity within the socket where it cannot cause a short. As for the damaged extracted wires, I just re-strip them to expose the needed extra bare wire.

A pair of sewing needles of the right diameter, inserted on each side of the captured wire, might serve to hold up the "trap door" enough to release the wire. The sewing needles should be hard enough to prevent the "trap door" from cutting into them and preventing their removal.

I plant to investigate SeedSeller's technique, since I think it is valid if you have the right tool(s). In the meantime I will patiently pull and wiggle as I have been doing. I have a whole stack of fixtures still awaiting the overdriving conversion. I also have onions, pansies, and african violets growing under overdriven fixtures and I will be planting a flat of coleus tonight. All of those little plants thank you, Zink.

-- Burton --

After my last post, I decided to investigate why I couldn't remove the wires by your method, which do I prefer to use. Normally, you can slide a thin object (pin, nail, wire) adjacent to the wire and wedge apart the metal that is clamping the wires in. That is a standard technique with these types of inserts. Since I had plenty of extra sockets leftover from my customizations, I decided to investigate.

I found that there were 2 slightly different wordings stamped on the backs of them, so I took both types apart. Internally, they were exactly the same.

First off, I found that the two adjacent insert holes, while connected to the same piece of metal, do not share the same "clasping flap" of metal. This means you cannot insert a wire, or whatever device, into one slot to relieve the gripping pressure on the wire inserted in the adjacent slot.

Second, even though I had FULL view of the internal workings, I found it nearly impossible to insert anything useful along side the wire I wanted to remove. The only device that could possibly work would have to be - needle thin, bent at the end for about 1/8", and as strong as steel. Even with a full view of the insides I could not do it.

Although I was dismayed that it was harder than I thought, I did figure out how to "twist and wiggle" the wire even better than before. I don't see how you do it with these particular sockets (tombstones).

Zink

You are a better man than I. I just sat here and busted up 2 more sockets. I think some of these have more glued places than others. I am sure I have had the back off of one of these things before.. without breaking it.

At least there are other ways to get the job done. Some people are more comfortable cutting and splicing in the new wire. I do it that way when I have to.

Zink

Thanks, SS1

Looks like I need some help.

I just receieved the HD shoplights with the Sunpark SL-15 ballasts via UPS. Wired a couple up as per your instructions and diagrams (quite easy and straight forward), but the bulbs seem no brighter than a normally wired fixture!

I have tried both T8 and T12 bulbs. I have also removed the wires from one set of "tombstones" and moved them over to the other set in case the first was bad. Any suggestions!

The first thing that I thought of was that maybe you had combined the wrong wires at one end of the fixture. I have encountered low light output many times. Once, I found I had combined the 2 red wires together on one pin, and the 2 blue wires together on the other pin. The correct way is to combine a red/blue and a red/blue. I made this mistake even after I had rewired a bunch of fixtures.

The other low light problem I have had, several times, was because I thought I had inserted the wires well into the socket/tombstone. That mistake was easy to fix. Usually one wire would fall back out after I moved the fixture some. I was happy to see it happen, because then I knew what my problem was.

It is also possible to have a bad or weak ballast. I haven’t had that happen yet. Since I have plenty of room on my workbench, and plenty of jumper wires, I would separate the wires back to the “normal” condition, with 2 bulbs, and see if the ballast still lights both of them normally. If so, it should overdrive just fine – I would think.

If you do compare a normal fixture with an overdriven one, make sure you compare T8’s with T8’s, and T12’s with T12’s. They two types can be different enough to skew a comparison.

In my experiences so far, every time I had low light problem, it was fixable.

Zink

"After a second (and third) look, it does appear that the overdriven bulbs are a LITTLE brighter than the normally wired ones. Maybe 20% brighter. Is this normal, or should I expect a larger increase in brightness?"

In my experience, it's normal that when you first apply power to the overdriven fixture that at least one bulb is not as bright as it should be. If you have read all the messages in this thread, you will see that I always have to "futz" with a fixture to get it working properly. When it is working properly, it is a lot brighter. The 70% figure that is usually quoted is accurate in my estimation.

I always do a table test of a fixture as soon as I complete it. It put it on a table, face up, side-by-side with a normally driven fixture and turn both on, and then observe and compare. I have never had a fixture work optimally upon first power up. I notice which bulb is dimmest, power off, and swap ends on the "dim" bulb, and re-apply power to both fixtures. If there is still a problem, I interchange the bulbs in the overdriven fixture, keeping the end orientation the same and retest. If there is still a problem, I swap ends on the weaker bulb and retest. I refer to this process of repeatedly changing the bulb orientation/installation as "futzing" with the fixture.

I have no idea what is actually going on. Maybe I am just roughing up the bulb prongs or the socket contacts. It isn't supposed to matter how you install the bulbs. For me, it appears to matter, and the process of finding a "sweet" bulb installation is a matter of trial-and-error. As soon as I find it, I leave the overdriven fixture in that configuration and put it aside. Days later when I install the fixture in a plant stand over seedlings it appears to have retained that "sweet" bright configuration.

On one shelf of my main plant stand I have one non-overdriven fixture, and it stands out in stark contrast with the two overdriven fixtures beside it on that shelf.

When you are comparing bulb brightness, make sure it is the exact same make and model of bulb. My cool white Philips T8s look brighter than my warm white Philips T8s, and that holds whether the bulbs are in an overdriven fixture or a normally driven fixture. If you compared an overdriven warm white bulb with a normally driven cool white bulb, you might be disappointed and your 20% figure would be about right.

If futzing with the bulbs doesn't work, you might want to follow Zink's suggestion and open the fixture and make sure your connections are all good. I have started using insulated crimp connectors instead of screw-on connectors for more "solid" connections, although my first two screw-on fixtures are working well too.

I mount the second ballast at the other end of the fixture and pop-rivet it in place there, along with a second ground wire connection to the fixture body. I scrape off the paint at the second ground wire connection point to assure a good electrical connection. A Dremel tool would make that easier. I was worried that mounting the ballasts side-by-side might cause problems, although that is probably unfounded. But the opposited-ended scheme does give better mechanical balance to the fixture. I do have to add a couple of "parasitic" line voltage wires down to the second ballast. Good electrical connections are important, but I agree with Zink that soldered connections are unneccessary.

Incidentally, I am glad UPS at least delivered overdrivable fixtures. That wasn't an absolute certainty.

-- Burton --

Thanks for the advice. I did go through and thoroughly check the wiring, connections, bulbs types, etc. Everything is solid. The fixtures are working, and they are brighter than normally wired ones in side by side comparisons (with the same type bulbs).

I think it may simply be a matter of subjective comparisons. When I look at the overdriven bulbs, I do not see a 70% increase in light output, but I do see a noticable increase. I have now replaced the original three fixtures over my plant area with three overdriven ones. The area is definitely brighter (and warmer), so I think everything is working as it is supposed to.

Another possible problem with visually judging the light increase is that by the time I have rewired and tested the fixtures, I am nearly blind from all that light in such close proximity! Talk about seeing spots!

Thanks again, guys.

I cut one flange off the side of each reflector. Actually, I didn't cut
them myself. I took them to a friend who has a table saw with a blade for
cutting metal. He cut them for me on the outside of the groove, and filed
them a bit afterwards.

I have two cool white 34W T8 lamps in the center and warm white T12 lamps
on the outside for the second phase of my "one month cool, one month cool
and warm" routine. I put the warm whites on the outside because
phototropism tends to follow the cool whites, and I want them to grow
straight.

I have two probably-non-overdrivable cheap shopligths. I took them apart
to see. They have a ballast on one end of the fixture. The ballasts have
no name or markings, just some resistors, a thing like a shiny brown
sausage (capacitor?) and a heavy square ring (transformer?).

Now I can clean up and put away the electrical stuff and concentrate on what I
am groiwng.

Thanks, Zink and everyone for the help and inspiration.

Thanks Zink for the information.

Did you mentioned earlier in the post about driving a 22" CF bulb?

I have a question about the ability to drive 8w t5 bulbs with the Sunpark Ballast.

Is it possible to do it and how would I wire it? Would I wire them in parallel? How many 8 Watt T5 bulbs could I run of 1 ballast?

Any information would be greatly appreciated

I discovered that one of the best bulbs to overdrive with an electronic ballast is an FT40TT lamps, such as the Philips PL-L40w or the Dulux-L 40w. They're difficult to look at when OD'ed.

I mounted 4 of them across a large reflector (about 12" wide) from an old 2-lamp shoplight, which I cut in half!(24" long). I haven't used the thing, yet. Every now and then, I just turn it and and laugh at how bright it is. I think I'm getting about 18,000 lumens from the thing! That's equal to about a 250w MH.

Do you know the designation/name of the T5 bulbs. I recently found that an overdriven Sunpark SL-15 supplies EXACTLY the specified mA to drive a Philips 54w T5/HO bulb (I measured it).

I have generally found that, within tube sizes, for whatever wattage a ballast will drive, it also drive nearly that same wattage added together from smaller lamps wired in series.

For instance, using 2-17w T8 lamps in place of 1-32wT8. The lamps should be wired end-to-end, wiring BOTH lamp pins together. You can even SHORT the two pins (preferred) on the facing lamp ends, but DON'T short the leads to the ballast (unless it is an INSTANT-START ballast, then ALL lamp pins are shorted at their ends).

Zink

That is exactly what I was hoping I could do, but needed confirmation since my eletronic knowledge is not good enough to be confident in it.

I am actually trying to increase the wattage density using UVA (Blacklights) Bulbs for use in a Photocatalytic Reactor. I need to use short Bulbs because of the reactor design. I am still determining whether I will be using f8T5's or f15T8's so I don't have a model number yet.

What do you mean by shorting all the pins at their ends since I am hoping to use an instant start ballast?

I hate to take up all you time on this post.

Is there any place you found on the web that explains how to wire bulbs in series and how many bulbs you can wire end to end or is this from your knowledge and experiece?

Thanks for all your help

Fun experiment.

RJ

Yes, they are triphosphor, as are nearly every single CFL being manufactured nowadays. The "way too small" SPD graph on the Philips product info page shows the color temperatures available. Their difference in colors appears mainly due to changes in the amount of green and blue being output, with the 4100K lamp delivering the most blue:
http://www.lighting.philips.com/nam/prodinfo/compact_fluorescent/p2812a.shtml

It sounds like you lit one up. Did you get to OD one of them?

dbri,

From extensive reading of lamp design discussions, there should be no more UV coming from a single overdriven lamp than using two normal lamps, all of the wavelengths get boosted in intenity. The UV ouput just increases with the visible light. No more dangerous than using a higher wattage to begin with, or using more lights to begin with.

By the way, I liked your prairie pics and the "get-a-life" links. I need the reminder.

Zink

Is the ballast by default able to handle something like a T5 bulb (assuming you've refitted the plugs for a T5 lamp and adjusted the distance). Or do you have to overdrive it in order to even power a T5?