I'm building an SCR based powersupply and I'm working through some of the control circuitry at the moment. I have it breadboarded and it works fine, now I need to modify it a bit.
The supply is for a tesla coil and I'd like to be able to control it from a safe distance. I could just keep the supply at a remote location and run the output straight to the coil, but I'd rather not have to haul the supply around.

I'm planning on using a 50' fiber optic cable for the firing angle control. The problem lies with the fiber optic reciever which has a minimum frequency of ~200kHz. My plan is to take the 120Hz variable width from the original circuit and 'and' it with a higher frequency signal. then use an envelope detector on the other end to just get the variable width signal out.

Does it look like it will work?

Attached Images

	envelope_detector.gif (7.9 KB, 10 views)
	my_circuit.gif (21.8 KB, 6 views)

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Jeff
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To the pessimist, the glass is half empty.
To the engineer, the glass is twice as big as it needs to be.

 

That should work, but you don't really need a diode, just a low pass filter on the input of the transistor will do.

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