PC PSU?

[audiocommander]

Hi,

I recently purchased two very cheap PSU's from Pollin, obviously for use with Personal Computers.

They deliver +5V@6.5A, +12V@650mA, -12V@650mA and -9V@160mA.

Now I wonder if I could use these for my MB-FM, because the 6.5A@5V seem a bit much? Can this destroy something? Or is there a electronic part that restricts the drawn Amperes?

Thanks for any comments,

Michael

[Mr modnaR]

the MBFM circuits themselves only take what current they need. the 6.5A quoted is a maximum threshold that the PSU can provide. as long as what you are powering requires less, there should be no problem. it was suggested to me by TK, that PC PSUs were not suitable for my MBSID project, because they are switching power supplies, which means they'd introduce lots of high frequency noise into the SID. as to whether this applies to the FM, i don't know, but it might be worth looking into more before commiting yourself.

hope this helps.

[SLP]

I was thinking of using a cheap 150W-Pollin-PSU, too.

I've found a tutorial which describes how to build a second PSU into a PC.

unfortunately it's only in german.

http://www.moddingtech.de/tut_2tes_netzteil_01_de,59.html

the 2 most important things are:

- just bridge the 2 marked pins of the ATX-Plug

- some PSUs only work when somethings connected to them (fan, etc.)

hope this helps, too  :)

matthias

[Mr modnaR]

normal PC PSUs are a bit bulky for my liking, but you can get 120W PSUs the size of the ATX plug:

[SLP]

Did I understand you right?

is the PCB on the photo a complete 120W PSU???  :o :o

is there a way to shield the PSU so that it doesn't influence the SID-circut ?

matthias

[Mr modnaR]

well, no. technically it's a DC-DC converter, you need to input 12V.

as for shielding, just stick it in a metal, earthed cage.

[SLP]

as for shielding, just stick it in a metal, earthed cage.

isn't a PC PSU usually built in a metal housing?

[Mr modnaR]

well, yeah, the big ones are, i thought you were talking about the little one i posted the picture of.

[Mr modnaR]

when i said ATX PSUs introduce high frequency noise into the SID, i meant through the power lines, not through the air.

[SLP]

So, there is no way to get the ATX-PSU-Noise out of the SID.

ok.

thats all I wanted to know.  :)

good night  :-*

;)

[Mr modnaR]

well tk reckoned that some people had success with switching PSUs, but you need more bits on top of the PSU (for noise suppression) than if you just built a linear PSU. honestly, it's not that hard to do it yourself.

[audiocommander]

thanks a lot for your input Mr modnaR & SLP!  :)

I think I'm going to try the PSU I purchased.

If I'll notice any noise, I'll post it here and will build the FM-PSU for +/-12Vs

well, no. technically it's a DC-DC converter, you need to input 12V.

so, do I understand it right, that this thing is producing -12Vs?

would be definitely an option, 'cause the PSU I purchased is 30 cm long and weights half a ton (well, not exactly, but you get the point ;D )...

Cheers,

Michael

[Mr modnaR]

i'm pretty sure it's standard ATX, which looks like this:

[audiocommander]

cool :)

thanks!

[SLP]

@ Mr Random  ;)

do you have a datasheet for this DC-DC-converter?

[Mr modnaR]

here's the link to the website it's available from, but there's no specsheet, i suppose you could email them:

http://www.mini-itx.com/store/?c=10#picoPSU