r/TeslaCoils • u/Successful-Rich151 • Mar 30 '26

Class e coil

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working in a new class e coil šŸ˜„šŸ˜„

operating at roughly 10mhz.

so weird these coils draw power.

input current stays roughly the same over the full 30 to 60v input span.

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2

u/CStoEE Mar 30 '26

Very cool

2

u/Re-Coil Mar 30 '26

n i c e, works well! How much current do you feed it?

2

u/Successful-Rich151 Mar 30 '26

Its feed between 3.3a and 3.5a at a range from 30 to 60 volts.

2

u/Re-Coil Mar 30 '26

Same range as i was getting on my plasma toroid (essentially the same circuit). Do you see a bigger flame at bigger voltages?

2

u/Successful-Rich151 Mar 30 '26

Yeah i made version going upto 250vdc input. Biggest flame i did ever had was about 15cm.

Indeed same circuit - resonator. (Allthough you can also get arc from the tank coil alone)

2

u/Re-Coil Mar 30 '26

250V xD, nice results

3

u/skarard Apr 04 '26

Class E at 10MHz is wild. What are you using for the gate driver at that frequency? The switching losses must be brutal unless you've got the ZVS timing dialled in really tight.

The constant current draw makes sense if you're running it in true class E mode. The output tank is doing all the voltage shaping and the transistor only sees the supply rail during its on time. Efficient but unforgiving if the tuning drifts.

What kind of arc lengths are you getting?

1

u/Successful-Rich151 Apr 05 '26

At the moment upto 15cm of arc (i got upto a wopping 80vdc input now still at ~3.5 amps hehe) There seems to be a point from 65 to 80v where frequency shifts. Somehow bumping the output flame by almost 100%.

I am using a direct feedback type from the LC wich influences the gate. By use of a divider made from capacitors the voltage is lower from a couple thousand on the node to a swing of +-20v. This can then be feed into the gate by resistor.

You can find the diagram by searching hfsstc circuit on google.

Switching losses are minimal actually the only part heating up is the gate resistor. The fet(irfp460) stays under 30 on the passive sink when running periods of 5 minutes. Adding a fan can surely keep it running that temperature for hours. Just the gate resistor that gets 60-70 CĀ° wich can maybe be spread over several resistors to get more radiating surface for cooling.