Multiple output and voltage PSU

[Guest]

Just a quick thought - I have been looking through all the PSU designs and looking at Craig Andertons design for a multiple output PSU
And am wondering how come nobody has designed an off board PSU and distributor
I was imaging a rack unit with a transformer and AC inlet in - with multiple DC outputs that provide 48v phantom and a variety of voltages dual +15/-15v, single 24v, dual 24v etc.... for all of the Projects here.
You could then have 4 or 5 outlets from each different power source and use standard DC cables to send power to the different modules and have standard DC sockets on the Project boxes.
Surely that would provide better noise reduction - having the power unit of board and by buying a large enough transformer you could power all your projects from one rack unit (and be cheaper?)
Or in my newbie thinking have I missed something important?
Grounding?

 

[sismofyt]

You could, but you would need seperate regulators, heatsinks, caps and resistors. Cost money and takes up real estate.

I think it's much better to design the PSU to the actual circuit than using a do-it-all. Also, using the same PSU with multiple voltages to supply several circuits can get tricky and sound worse than using seperate PSUs.

The idea is neat, but I don't think it's usefull, imo that is.

 

[sismofyt]

Also, it's not a good idea to have the Vregs far away in a seperate box, especially if the circuits are not class A (constant current draw). It's always better to put the Vregs as physically close to the amp as possible.

However, you could make a do-it-all PCB that'll accept various LM78XX/LM79XX types since they use the same pin config. Just use 40V caps. Or use LM317/337 that are variable from +/- 1,2-37V.

 

[Guest]

Does somebody made a controlable high voltage PSU 0-400V ?

 

[sismofyt]

Or you could make a box with a big unregulated +/-35V PSU at say 500W, that could supply your modules, or whatever, each with it's own Vreg(s). That would be the best compromise, imo. I still rather have totally seperate PSUs.

The EMI TG desks used a big 50VAC trannie in a seperate box, with DC regulation and rectification in each module. That is a very good idea. I always thought that using a big external DC supply (often with 50 feet of cable) and no regulation in the desk, 'cept decoupling was a bad idea. I've modded a desk to have the regulation IN the desk and that really made it a lot tighter sonically.

Many many ways to skin a cat, just ask Dave :wink:

 

[sismofyt]

The problem with making a 0-400VDC varaible PSU is the heat. Say that you need 6V 1A, the you'd be wasting more than 400W :shock: , if the PSU is done conventionally. You'd have to do a switcher PSU (difficult and not DIY if you ask me), or use multiple tappings on the trannie that automatically get's switch in and out.

A 150-400VDC PSU would be better and easy to make.

 

[sismofyt]

Surplus sales have a lot of really good cheap PSUs. Too bad shipping to Europe is so expensive :evil:

I wouldn't bother DIY'ing one, I'd just buy one and DIY some real fun stuff instead :grin:

www.surplussales.com/PowerSupplies/PowerSuppliesMain.html

Surplus sales got some insane PSUs there! :shock:

 

[Guest]

I found this and I think that is suitable for tube circuit testing.


http://www.geocities.com/tjacodesign/300vsup/300vsup.html

 

[Guest]

I found this and I think that is suitable for tube circuit testing.


http://www.geocities.com/tjacodesign/300vsup/300vsup.html

 

[gyraf]

That looks like a simple way to do it..


Jakob E.

 

[Guest]

I am just in the middle of the resizing. Some boards do this automatically, but no problem, I think that now will be OK.

What type of PSU do you other people using for high voltage tests ?

It appears that Geocities doesn't like external links.
Here is the schematic:

 

[gyraf]

I use a psu that is more or less like the G9 supply, with a voltage meter and a switch+resistor to discharge it.

 

[Guest]

[quote author="gyraf"]I use a psu that is more or less like the G9 supply, with a voltage meter and a switch+resistor to discharge it.[/quote]


Does it have variable voltage ?

 

[gyraf]

no.

 

[BradAvenson]

If you want a variable voltage supply for testing, maybe you could use a cap-choke-cap supply and use a variac in front of the power transformer.

Just an idea. The brown-out may be bad for your power transformer though.

 

[CJ]

I have a remote pwr supply.
The noise reduction is incredible.
You can crank up any box I have to max level, and all you will here is a little hiss from the actual tubes, thats all.
It is well worth it.
Combine an offboard supply with dc heaters and you will have quitier stuff than any manufature makes.

The Fairchild pwr supply has a pot that sets the voltage. It dosen't go all the way to zero, but it goes from about 175 to 300, at least mine does.
No heat either.

I don't have a problem with dc regs being on a seperate chassis, as there is additional filtering in the racked boxes.
cj