[whubbard]

So I'm going to be building a variable power supply kit:
http://www.electronickits.com/kit/complete/powe/ck402.htm

They have the schematic here:
http://www.electronickits.com/kit/complete/powe/ck402.pdf

But I think I would rather just buy the kit, than make the PCB myself, it's just easier and the cost is negligible. I will be replacing the LM317 with the LM388T so I can use up to 5Amps of current.

Now I am going to need a 32V power supply and this is where I'm looking for some suggestions.

Could I just use a 30VAC 5A transformer alone?
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=HM561-ND

Or is there a cheaper way to make a 30/32V power supply?

Thanks,
West

[Niteshade]

Hello-
You could use a 30v transformer for the Lm338T since it wants around a 40v input. 30x1.4=42v.

A 30v transformer cannot be used alone with just a bridge rectifier and filter capacitors because, as stated above, the peak voltage will reach around 42v. 

Transformer current should be around 8 amps or more for the regulator.

The regulator is easy to wire and no printed circuits are necessary- a few good terminal strips will work just fine. Find a nice heat sink for it, preferably with the TO-3 package based holes already  drilled for you.

Cheap transformer source: Do you have an old stereo receiver around that is 30-50 watts per channel? They have nice power transformers in them and the voltage should be about right.

[Occam]

West,

You're welcome to a Signal Transformer A41-175-28
http://www.signaltransformer.com/Data/Datasheets/A41.pdf
the detritus from decomissioned Felicias.....

-Paul

[whubbard]

Paul,
Your too kind.

PM Sent.

-West