Ramsey PG-13 Plasma Supply

alan sailer, Fri Jul 01 2016, 06:34PM

I am wondering if anyone here has circuit information on the Ramsey PG-13 high voltage supply. I am making some plasma tubes and am trying out different power supplies. I was more than willing to just buy one but they no longer make them...

I am sorry in advance if asking for circuit information is a sin. I kind of figured since the circuit is no longer sold, giving out information on it might be OK.

Thanks for any help.

Cheers.
Re: Ramsey PG-13 Plasma Supply
hen918, Sat Jul 02 2016, 12:12PM

Looking at their instruction manual, their circuit is a very simple and universal Royer oscillator: Link2
This one works very like the ubiquitous Mazzilli Driver, but the gate drive is fed by a separate centre-tapped winding and uses bipolar transistors instead of MOSFETs. This makes it a cross between the original Royer oscillator: Link2 and the Mazzilli Driver: Link2

These are often used in small low input voltage CCFL circuits (with a capacitor across the output to limit current) and can drive most small high voltage loads.
Pros: Cheap, Low Part Count, Reliable
Cons: Fairly low efficiency (no good for high powers).
Re: Ramsey PG-13 Plasma Supply
Hazmatt_(The Underdog), Sat Jul 02 2016, 03:03PM

That driver will tend to run a bit hot because the transistors are always pulling some current.

1. The heatsinks need to be separated and not touch each other, if they do that circuit will short out and not operate.
One transistor needs to be on while the other is off.

2. The base winding is anti-phase to the emitter winding. This is very important to the oscillator. If the windings are in-phase then it will not start oscillating, in-phase would make it an amplifier (which is also handy to know sometimes)
Re: Ramsey PG-13 Plasma Supply
alan sailer, Sun Jul 03 2016, 01:45AM

Wow!! Thank you, Thank you very much all. I'm very happy to get the schematic.

My need are for medium power (~20-60watts) at about 10-20kV. I am currently using the plasma globe driver circuit push-pull MOSFET from the old article in Electronics Now. It works well but I want to explore other designs.

Cheers.
Re: Ramsey PG-13 Plasma Supply
Conundrum, Sun Jul 03 2016, 05:44AM

Might be useful, something I am working on needs a circuit that only outputs HV when the video feed is on.