It's an interesting balanced amp, but there is no "circle" in it, it's not a circlotron 
You got just one PS and it's ground-referenced. Circlotron is basically a balanced push-pull with load across the bridge (as in Wien bridge, not as in "bridged amp"). Like this:
You got just one PS and it's ground-referenced. Circlotron is basically a balanced push-pull with load across the bridge (as in Wien bridge, not as in "bridged amp"). Like this:
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Yes, I do plan to build upon this concept. I already have constructed a balanced, cascoded mosfet/power jfet amp similar in design minus the top choke and coupling caps. Basically, all I need to do is add the choke and caps and I'm in-like-flint.
In my sims I noticed that it's very important to have a small value resistor on the lower choke center tap. The LU1014Ds would fry otherwise. Also, a couple volts from a negative power supply seem to improve the wattage curve on the jfets.
What's cool is that it'll drive a 2 ohm load and deliver 100 watts, or more, in the process.
BTW, I should mention: the mosfets count must be quadrupled at a minimum.
Oh, and it takes 10 volts on the inputs to achieve 120 watts output.
In my sims I noticed that it's very important to have a small value resistor on the lower choke center tap. The LU1014Ds would fry otherwise. Also, a couple volts from a negative power supply seem to improve the wattage curve on the jfets.
What's cool is that it'll drive a 2 ohm load and deliver 100 watts, or more, in the process.
BTW, I should mention: the mosfets count must be quadrupled at a minimum.
Oh, and it takes 10 volts on the inputs to achieve 120 watts output.
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So I had a closer look this afternoon and did some quick sums.
Assuming we build a power amp with Iq = 4A (no pont building circlotron pre's), and we allow the caps to drop voltage by say 0.3V at 10Hz half cycle. We would need somthing like 0.7F of capacitance for each half. The chokes are then not too bad with such an amount of capacitance. Probably 3mH will do fine. I would guess 2 caps 1F 24V to be around USD400, plus 4 chokes at about the same price (DCR < 0.05ohm).
I guess I can either buy many 24V 100aH car batteries for that price, or separate 1kVA transformers, ..., etc. Maybe useful for tube guys, but this is the Pass forum -- Class A MOSFETs at high bias.
Still, the idea is clever, one has to admit.
Patrick
Assuming we build a power amp with Iq = 4A (no pont building circlotron pre's), and we allow the caps to drop voltage by say 0.3V at 10Hz half cycle. We would need somthing like 0.7F of capacitance for each half. The chokes are then not too bad with such an amount of capacitance. Probably 3mH will do fine. I would guess 2 caps 1F 24V to be around USD400, plus 4 chokes at about the same price (DCR < 0.05ohm).
I guess I can either buy many 24V 100aH car batteries for that price, or separate 1kVA transformers, ..., etc. Maybe useful for tube guys, but this is the Pass forum -- Class A MOSFETs at high bias.
Still, the idea is clever, one has to admit.
Patrick
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If you want to build a inductorloaded circlotron you could build this one.
Its an old design of mine. I build one 2005 and it worked realy good.
The inductor is a bifilare winded big E-core transformer with about 2 x 150 turns of 2,5 mm2 isolated coppercable.
With 2 x 15 volt powersupplies i could get 30 watts out of it. (probably more but i couldent measure it that acuratly)
Johannes.
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