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Does Putting Diodes in Parallel Lower Their Voltage Drop?

Part 2: The procedure.

How To Test Voltage Drop of a Diode:

Setup:

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Point your mouse at the various parts of the image.

This is the simple schematic to follow to test your diode's voltage drop. Let's go over the three parts of this setup individually:

• For accuracy, the mutimeter being used needs to be a digital one (not analog, with the moving needle on the chart with them numbers behind it), set to voltage detecting mode (or somesuch). The more accurate the meter is, the better, but you can get away with almost any el-cheapo meter.
  NOTE: If, during testing, you find a negative voltage detected on your meter, swap the meter probes around.
  While it is possible to determine the voltage drop of a diode with your meter backward, I prefer the easy, simpler way.

• The voltage source needs to be a previously known constant. Use your volt meter and record (i.e. write down) exactly what voltage it is. This step is important. Since very little (if any) current is being used up during testing, the voltage source can be a depleted battery, a pre-charged capacitor, or even a nuclear generator if you have the government funding....
  The voltage source has to be higher than the predicted voltage drop of the diode to be tested, yet lower than the maximum voltage of the diode (easy).
  Otherwise, you won't get a good reading (bummer).
  One thing to remember: When testing a handful (10 or so) of diodes in turn, don't change the voltage source! (Explained later)

• Diode to be tested: Pretty much any regular diode. Make sure it's put in correctly, or it'll explode, injuring any egos nearby.
  [Just kidding! As long as the voltage source is not higher than the reverse breakover and/or maximum forward voltage, no damage will occur.]

From this point forward, I will abbreviate "voltage drop" as �Vdrop�, and "voltage source" as �Vsource�.
I do this for my own convenience.

Small note before we continue: If your diode is backward, you normally won't read any voltage. This is good, unless if the diode is another kind not covered here.

The how-to:

Hook up your diode, voltage source, and meter. You should read a voltage that is noticably (in some cases, slightly) lower than your Vsource (we'll call this 'subtracted voltage', since it's actually the Vsource, but with Vdrop subtracted from it).
Write this result down, then test the next diode (if any).

Once you have your results, subtract this lower number from the original Vsource's number.
A pseudo-equation will clear things up:

      (Vsource's voltage)
   -(Subtracted voltage)
             &nbs p;         (Vdrop)

This procedure will yield your diode's Vdrop.
Now, if you change your Vsource constantly, you'll have to change Vsoure in the equation, meaning extra math (Ugh!).

I know, I know, some meters have a "Diode Test" feature, but this test rig is easier for me to understand (I don't trust the 'diode test' setting).

Below are my test results for three common diodes that I purchased from Allelectronics.com.

Vdrop table:

Article continued in part 3.

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Or, skip to:

• Part 1: The Diode.
  
• Part 2: The procedure.
  
• Part 3: Diode Duet.
  
• Part 4: Mixing n' Matching two diodes.