diyAudio (
-   Power Supplies (
-   -   Basic high voltage regulated supply (

quasi 23rd December 2005 07:46 AM

Basic high voltage regulated supply
2 Attachment(s)
Hello Forum-Friends,

Here is a simple high voltage regulator circuit that can provide +/- rails from around 30v to over 100v at a few hundred milliamps.

I developed it as part of another project, but it never got included. Hopefully some forum-goers can find a use for it.

Many of the components were selected to take advantage of broken / discarded computer powers supplies (they seem to be everywhere).

The attached PDF contains the schematic, a brief (very brief) description plus PCB layout and tracks.


Jay 23rd December 2005 08:47 AM

Thanks for the schematic Quasi! This is what I have been looking for. Anyhow, I have a question...

I need this circuit to replace some circuit that I use for front-end supply of my amplifiers. I just copy the circuit (from other amp) without knowing precisely how to adjust for different Vi and Vo.

So I wanted to build "simple" circuit like this as a benchmark.

The question is, is this circuit suitable for front-end supply of state-of-the-art amplifiers? I need Vo=56V for my Stochino amplifier.

quasi 23rd December 2005 10:01 AM

2 Attachment(s)
This power supply should work very well as a front end supply. Just tie the grounds centrally and run +/- feeds.

Attached is a photo of one I built to give you an idea of the regulators, transistor & heatsink configuration.


jackinnj 23rd December 2005 12:34 PM

just to be safe, you should put a 1N4007 anode connected to the top of R3, cathode to the input node (junction of D3,D4)

and vice-versa for the negative supply.

quasi 23rd December 2005 01:04 PM

2 Attachment(s)

Originally posted by jackinnj
just to be safe, you should put a 1N4007 anode connected to the top of R3, cathode to the input node (junction of D3,D4)

and vice-versa for the negative supply.

Yes Jackinnj is quite right regarding the diodes. If the input supply goes short cct for whatever reason, any residual voltage on the output will cause large currents to flow through the now reverse biased regulators and through the shorted input. Though this would be a fault event anyway, there's no point in destroying the regulators.

I have updated the schematic and layouts to include the diodes.

Thanks Jackinnj.

Jay 23rd December 2005 01:40 PM

Thanks Quasi. I had to cancel my question to Jackinnj regarding the possible damage due to inexistence of the diode :) Honestly, I don't care with the 7812s. I'm worrying the transistors I have matched from more than a thousand pieces ;)

In case I can't find the transistors (but I have many of that type from amplifier drivers), what is the minimum requirement (ie Vce) from the transistor for 40Vac (56Vdc)?

Is 330uF enough or more is better? I have 220uF Cerafines and 680uF Blackgates. On board, already installed are 220uF Cearfine and 10uF Solen.

quasi 24th December 2005 04:28 AM

Are you talking about the transistors used in this regulator board or transistors you are using in your amplifier?

The transistors used in th regulator board do not need to be matched, but they do need to be very robust.

If you are seeking comment about transistor voltage requirements in your amp I will need to see the cct.

For this regulator boards capacitors, more is better. For the input say up to 1,000 uF and up to 100uF for the output.


poobah 24th December 2005 04:50 AM


I see you on other threads???

And you want me to be a partner???


quasi 24th December 2005 04:58 AM

Haaaargh !

You found out ????

Honestly the other threads mean nothing to me's purely technical....honest

poobah 24th December 2005 05:34 AM

Talk to you another day Quasi,

Help me bring science to the cable people...

My power supply with the big capacitors is telling me to come to bed.

best holidays to you!

All times are GMT. The time now is 08:57 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2