Ballast resistor construction

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Dan Knapp
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Joined: Wed Aug 06, 2008 12:34 pm
Real name: Dan Knapp

Re: Ballast resistor construction

Post by Dan Knapp » Wed Jul 04, 2018 11:58 pm

Finally got around to using the ballast resistor today. It worked fine, and I didn't see any signs of discharge (although I wasn't working above 20 kV). The idea of a putting liquid crystal thermometer strip inside the tube didn't work - too hard to see - so I just put a dial thermometer on top that I can read across the room. The temperature at the top got to 48 degrees C. max in two hours of running. After turning things off, the outer plastic tube was barely warm. It looks like it will work OK without forced air cooling.

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Dennis P Brown
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Joined: Sun May 20, 2012 2:46 pm
Real name: Dennis P Brown
Location: Glen Arm, MD

Re: Ballast resistor construction

Post by Dennis P Brown » Thu Jul 05, 2018 6:26 pm

Glad the power load isn't too high. A word of caution: the difference between 20 kV and 30 kV can be significant relative to corona's and how the system behave's. When one gets over 20 kV, especially in fairly dry air, the arc over's can be unusual and even somewhat inconsistent.

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