Now the secondary was finished, it was time to put it all together for a test. Since the toroid had not arrived at this point, a piece of aluminium duct was used instead. For safety's sake, the driver was powered up with only 30 volts rather than 600. The DC resonant charging circuit was hooked up, so the capacitor voltage would be about 50V.

Test with 30 volts

Since the toroid was smaller than the final one, 3 of the capacitors had to be unplugged to bring it into tune. Once tuned it gave enough output to draw a 2cm arc off the toroid, and give me tingles when touching nearby metal objects. Unfortunately the 30 volt power supply didn't like the RF field, and shut down.

Waveform with quenching (and poor tuning)

Better tuned, and quenching disabled

The quenching doesn't work too well because at these low voltages there isn't enough current in the tank circuit at the notch point to trigger the Rogowski coil. So it doesn't trigger until the first cycle after the notch. Hopefully this will go away as the power is increased...

This little test showed that nothing serious was wrong, so it was time to put it all together. The secondary and driver unit were bolted to a wooden frame and two copper strike rails were added. At this time, extra capacitors were added to the MMC, and an 8 meter long wiring loom was made to carry HT, trigger pulses, and auxiliary power, to the driver unit.

Et voila!

Closeup of the base

Who could resist sticking some power into such a mean looking machine, even though it was indoors with no proper RF ground, and the power supply wasn't even finished?

Not I.

Hooked up to 300V 150mA PSU


It tuned with 15uF of capacitance, and as the voltage was increased, the quenching settled in perfectly. The above sparks were created with an input of 300V DC at 150mA (charging caps to 500V DC) and a break rate of roughly 15bps. Just think what it could do with 4 times the bang energy and 75 times the power...

<<< Previous: The resonator Next: Short circuit protection >>>
Return to TC Page