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| BIPOLAR TESLA COIL |
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| BACK TO PROJECTS PAGE |
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air core step up transformer experiments |
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| Starting from my |
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I replaced them with a little bipolar tesla coil. The power source used is my |
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The construction was very easy, discovering the possibility to center the two concentrical |
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| current limited dual MOT supply (250 VA) |
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coils with plastic belts (with self-fixation) - look in the pictures. The coil is built around a central, rigide, small diameter PVC pipe.
FIRST LIGHT
For the first light I used a small secondary (R = 1.27", lenght = 9.44", N = 960 turns with 0.25 mm magnet wire, L = 14045.626 uH,
Cself = 4.1619 pF, Fres = 658.6 kHz), with a 11 cm diameter primary. Tapping for resonance I got 5-6 inches nice arcs at 90 vac into MOTs. Beyond this value I will need a bigger primary form (pri-sec breakdown). |
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MOVIE 2 |
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SPARK GAP RUNING - MOVIE |
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MOVIE 1 |
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SECOND LIGHT
I used a 14 cm diameter primary form. Input voltage to the MOTs is now 150 vac, without breaking the pri-sec insulation. I am using the graphyte electrode spark gap, with a 20 nF primary cap and 3 turns on the primary |
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| RESULTS: 9-10 inches arcs |
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MOVIE 1 |
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MOVIE 2 |
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NEXT STEPS
- bigger diameter primary or better insulation between coils (oil bath?), ball terminals for the output (higher voltage breakdown)
- I would make an Oudin coil, using an Arsonval circuit for the primary tank: |
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| This circuit would allow the primary to oscillate at high frequency, completely separating the output from the 50 Hz component from the HV transformer. The Oudin configuration (magnetically and electrically coupling) would allow a slighly spark lenght gain and will produce a lot of corona. |
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