Finished Tutorial for PressLab's DC-DC

Arby · 12-31-2001, 12:13 AM

Alright everyone, here it is!

http://mp3box.2y.net/ps/

If you have any questions, you can post them here, or send me an e-mail.

However, I'm off to bed now

Machs_FueL · 12-31-2001, 12:34 AM

arby i love you

CALIBOY · 12-31-2001, 11:42 AM

Thank you Arby...just what I was looking for!

cybuch · 01-01-2002, 01:20 AM

Ok, so now I'm lost, do I put this back into my power supply or is this my power supply? How do I get -5v and -12v? or do I need it?
Steve

Arby · 01-01-2002, 01:49 AM

This replaces the ac portion of your old supply. You wire the transformer back to the original power supply, and it takes care of the regulation and such.

cybuch · 01-01-2002, 02:48 AM

ok, that makes sense, but when I measure the voltage on my existing transformer its like 140v, 120v, on the secondary (while its still in the power supply). I'm sorry but I'm having a little trouble. Heres how I think it works and you tell me, it comes into the transformer as 120vac and then it is supposed to be 3.3vac, 5vac, 12vac out, then into some rectifiers. But when I use my multimeter I get strange readings.
Steve

SkinnyBoy · 01-01-2002, 04:46 AM

Yeah, I got lost too trying to work out where everything connects. BTW. your transformer may have the primary winding split into 2. one on the very outside, and one on the very inside, and it may also have 2 copper strips..

cybuch · 01-01-2002, 10:53 AM

ok, I think I am starting to understand this thing, we dont care what the output of the transformer is, just as long as it is the same as what it was before we started. We are just tring to get the same output from the transformer off 12vdc and we were with 120vac. Now, what about the other trnasformers that are running off the ac section, do we not need them?(I have 2 small ones) are we bypassing the ac section all together? so I just put the secondary part of the transformer back into the old location and use the new circuit we just made for the input on the transformer. I hope I got this right.
Thanks
Steve

cybuch · 01-01-2002, 12:03 PM

ok, what happends if you break the ecores? Are they no good now? Or can I piece the two parts back together?
Steve

Arby · 01-01-2002, 05:38 PM

I dunno, have to ask presslab

I broke one, but I have so many old at power supplies sitting around that I just grabbed another one

presslab · 01-01-2002, 07:46 PM

Quote:

Originally posted by cybuch:
<STRONG>ok, what happends if you break the ecores? Are they no good now? Or can I piece the two parts back together?
Steve</STRONG>

If you break the E-Cores, they will no longer work right. No matter how well you glue them, it doesn't matter. They are pressed into shape with extreme pressure, and heat because of pressure. If you glue them you destroy the lines of flux in the core. This most likely will cause the transformer to make noise or heat up, or possibly cause the MOSFETs to overheat. This is also why you need to pull the two cores tightly together.

Presslab

SkinnyBoy · 01-02-2002, 01:06 AM

yeah, so don't break it!!!!!! :P
you know what??
this whole thing is stupid, you know why?? because you don't even need the old power supply board, do you?? all you are using from it is the caps, inductors, and diodes for the filtering, and the feedback part of the circuit, so, why doesn't someone design a circuit that has all that in it so you don't need the original PS board, and then you could make printed circuit boards.. Or is there more on the board that is being used???
Is the IC on the board still being used?? no-one seems to know...

cenwesi · 01-03-2002, 06:12 AM

ok is it just me, why is the supply list empty ?

SkinnyBoy · 01-03-2002, 06:31 AM

what, the parts list???
hmm..
let me just have a look at it...

Nope, its all there, or wasn't that what you were talking about??

[ 01-03-2002: Message edited by: SkinnyBoy ]

Arby · 01-03-2002, 08:36 AM

I only listed the mouser part numbers for the parts I got from mouser. The resistors and capacitors you can get from radio shack or fry's or etc.