JFET-only Circlotrons without negative feedback

[jpatay]

Alexei Semin assembled the Circlotron according to the circuit with an interstage transformer.
Circlotron on silicon carbide transistors. - YouTube

 

[savu]

I found a nice DC protection for the speaker designed especially for Circlotrons

 

[jpatay]

Yes, I posted in another thread:
https://www.diyaudio.com/forums/att...60-current-feedback-mosfet-circlotron-24v-gif

 

[Yurik_V]

Manufacturing PCB you can order here:
Simple Speaker Turn-On Delay and DC Protector - Share Project - PCBWay

 

[savu]

I’ve ordered two big cases from Gianluca over on the Pass forum and I’m seriously thinking of building this circlotron with these as output devices: https://www.mouser.ch/ProductDetail...cjbzSfp1HmcdgVquUvSSfNXmeAUj/AkiBiQjZpDl1Sw==

Hope I won’t change my mind in the next month

 

[mbrennwa]

I was a bit confused by the UJ3N065080K3S, but maybe it was just me. See here: The Zenitron

 

[alexopth1512]

I have already these in my possession so i will also build with these, but I would try the 65K3S

 

[jpatay]

I ran an circuit on 2SK2145. At the exit I put IRF4905 ( P-channel), which I found in my nightstand.
Square wave - 60 kHz. Output stage current - 180 mA.

 

[Svjatoslav]

How does the quiescent current change from the moment it is turned on?

 

[jpatay]

When the amplifier is turned on, the current starts to decrease slightly and stops after J174 warms up. This is due to the drift of the J174.
After that, the current is stable on massive radiators.

 

[UltimateX86]

I found a nice DC protection for the speaker designed especially for Circlotrons

Yes, I posted in another thread:
https://www.diyaudio.com/forums/att...60-current-feedback-mosfet-circlotron-24v-gif

hi

10.0 cap on circlotron output is 10p ?

thanks

 

[jpatay]

This is 10 μF. 10pF - 10.

 

[Yurik_V]

hi

10.0 cap on circlotron output is 10p ?

thanks

10uF NP capasitor

 

[UltimateX86]

Thank you both

I try to simulate the protection under ltspice to compare with what I already have, but I cannot find a PC813, PC814 or TLP620, by the way Mouser does not have one too, you have other references?

 

[jpatay]

Single optocouplers can be used. PC817 and others.

 

[UltimateX86]

Thanks ! super with 12v

 

[UltimateX86]

Single optocouplers can be used. PC817 and others.

HI,

Why using two opto on this one ?

it is for circlotron too ?

 

[jpatay]

Maybe the PC817 is in LTspice.

 

[jpatay]

it is for circlotron too ?

Yes.

 

[UltimateX86]

Yes.

OK but why using two opto on this one ?



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