Building a +/- 24v Regulated PSU?

[Destroyer OS]

This is harder than it sounds.

First I need help finding some really good regulators. The only ones I have found are on Parts Express and you know are $1.00 and probably an insult to the Cree Diodes I am thinking about using (no recovery time diodes).

I am looking at Peter's (PD) design for influence.

http://www.diyaudio.com/forums/attachment.php?s=&postid=805978&stamp=1136397897

I was thinking four Panasonic FM's instead of single FC's (I want Black Gates but there is no stock of the right size over 24v)

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P12407-ND

Then two FM 68uf

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P12926-ND

Finished off with the four 10uf FC's

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P11250-ND


Four Cree Diodes from Parts Connexion (1A)

http://www.partsconnexion.com/catalog/semiconductors.html

Then what transformer not sure, this is over kill but it should work... (way more than needed VA)

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=122-630

Any suggestions to make this a really good regualted PSU?

The intent is to go with some Borberly home made line-amps. The dual JFETs with a couple Vishay nakeds and maybe two teflon caps on the way in, nothing else in it.

 

[Destroyer OS]

I just realized I would be at .22mF with those first caps listed.

I am unsure where to get such capacitance except from a lot of freaking small ones.

 

[h_a]

Hi,

I just had a look at the Cree diodes and it seems they're really just Schottkys for high voltage applications.

You can save some money by using these nice Schottkys

http://www.vishay.com/docs/88941/v30100s.pdf
http://www.diyaudio.com/forums/showthread.php?s=&threadid=126816&highlight=

Good for up to 40V rails and available from Digikey.

Have fun, Hannes

 

[Destroyer OS]

Thanks for the suggestion.

I guess I was wrong about the caps, should be easy.

 

[sawreyrw]

I'm not sold on the Cree diodes, but they are silicon carbide, not silicon. They do have the advantage that they have very little stored charge, so they are much better than Schottkys in this respect.

 

[Destroyer OS]

Do you have any ideas on 24v regulators?

(Not sold, how come?)

 

[Minion]

Do you have any ideas on 24v regulators?

(Not sold, how come?)

LM7824/7924(fixed)

LM317/337 (adjustable)

😀

 

[glorocks]

How much current are you looking for?

 

[glorocks]

The Lm 78/79 and 317's are only good for about an ampere and must have heatsinks at currents over about 50-100 mA.

Even at low currents, it is best to heatsink the negative regulator, as they tend to run quite a bit hotter, and are prone to failure without the heatsink.

You can download the data sheets at www.national.com Be sure you follow the bypassing suggestions.

Also, bear in mind, that the 78 and 79 do not put out the exact same voltage. The 17 and 37 are adjustable, so the voltages can be trimmed to match.

With either chip, don't get crazy with the amount of voltage you're dropping. If the input voltage is too high, they will overheat and thermal out.
If you need more current, I'll send you a few helpful links.

J-