HV Tube bench power supply

[Marco audio]

Thanks for your replies.
Current source and pentode or triode strapped was a choice between response and milliampères.

 

[Marco audio]

Hello,i received my 50w 6v transformer.
It work well.Here is a 4,7k 25w resistor who's tortured:

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[Marco audio]

You dont really have to, that capacitor is there to direct AC from the main output bus, its a high pass filter, that is not too critical to the functioning of the circuit. 47n-470nF will work OK.

Furthermore you can get a lot better gain by putting the error tube 6SJ7 in pentode instead of triode strapping it. for that the output divider with two 10K 3W resistors will suffice.

Here are photo's of a supply i built using two 6080/6AS7G tubes, VR150 reference(0D3) and EF184.

Theres a bit of theory behind these kind of supplies, ideally you want the EF184 to have a lot of gain, so it can counteract the ripple more effectively. I solved this with a 10M45S current source, if you load a pentode with a current source, you increase the gain by quite a bit. (Up to ten times last time i did some calculations)

If you want i have a few PCB's for this project leftover, they have one little error but are usable.

I speaked to you too fast, sorry.
I will try pentode wiring.
Thanks for PCB ,that's kind,but i don't need .
Regards

 

[Marco audio]

Hello,i have just tested the pentode mode with two 10k resistors:
Response is faster than triode strapped mode.
But it seems to me that the output voltage headroom is thinner:
Pentode mode: 182v to 293v
Triode mode:less than 150v to 293v (from memory,i didn't care of the 150v value)
Should i change the 43k anode resistor for a lower value ?

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[Marco audio]

I hade made a trial with a 22k 10w anode resistor :
Output voltage seems higher:186vto 295v
All trials were made with a 4,7k load.

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[Marco audio]

A trial with a sg2s (75v) voltage regulator tube gave me a little bad smoke near the ampermeter... and the tube brighted very strong but it can handle 30ma.
The output voltage has reach a lower value (near 150v) but can't reach 295v

 

[Marco audio]

Hello,

did someone tried this ?
A very fast voltage regulator: a CCS instead a resistor at the anode...
Any reviews ?

Regards

 

[v4lve lover]

Yes I have and your circuit will work fine, except that you may need to re-evaluate the screen grid divider, or better still, run the entire current source from the output.

 

[Marco audio]

Je vous remercie pour votre réponse.
La tension d'écran doit donc être très precise.je vais creuser.