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How do I find the secondary current of a DRSSTC Tesla Coil? Answered

I need to know the secondary current to determine what turns value to use for a feedback current transformer in the driver circuit.  The secondary capacitance, if that has anything to do with this, is 6.9424 pF.



3 years ago

There's no way to know exactly until the coil is built. Also I'd recommend primary feedback as secondary feedback doesn't always follow what the primary is doing and even when it does there's usually a significant delay (in addition to IGBT and driver delay). For primary feedback it's usually hundreds of amps at least even on small coils and the biggest that I know of is 6000A. For a ballpark figure you need to know the resonant frequency and then the surge impedance (square root of the inductance divided by the capacitance. As a rule of thumb the IGBT will always be the limiting factor (ie without OC protection that you preset they will blow up, bricks can do about 4-5x their current ratings peak). What I did for feedback was just use 2 32:1 transformers cascaded. Sure a single 1024:1 would be better (less delay and cleaner signal) but way too lazy to even think of winding that on a toroid core.


8 years ago

I highly recommend popping over to the Geek Group forums for this one:  They have a section just for HV questions...


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