Converted MiniATX Power Supply

[rjchu]

After seeing what some others have done, and needing more 5v and 12v power supplies, I picked up 3 miniATX and 2 regular ATX power supplies on clearance to convert for DIYC purposes. Below is the first of the miniATX's that I finished this afternoon. It has terminals for 3.3v, 5v, 12v and ground. I also converted the built-in 110/220v switch to act as the on/off switch with 110v as the "on". It was pretty easy and I recommend this as a cheap and easy power source for anyone in need.

Thanks,

-joni-

[dmcole]

Very nice.

\dmc

[Greg in Canby]

I also converted the built-in 110/220v switch to act as the on/off switch with 110v as the "on". It was pretty easy and I recommend this as a cheap and easy power source for anyone in need.

Now that's a great idea! Good looking mod too!

[imbluenote]

I just finished one yesterday but with binding posts instead of the terminal strip. But I have a question for the ones smarter than I on here. I've read various posts about how for like the fm 02 a power supply like this could possibly cause hum. A filter/regulator could be built but if 12v was desired you need to have an input that included the drop voltage of the regulator. Can
You connect the 3.3 and 12v outputs to come up with 15v from the power supply that could then be filtered to 12?

[Wayne J]

I just finished one yesterday but with binding posts instead of the terminal strip. But I have a question for the ones smarter than I on here. I've read various posts about how for like the fm 02 a power supply like this could possibly cause hum. A filter/regulator could be built but if 12v was desired you need to have an input that included the drop voltage of the regulator. Can
You connect the 3.3 and 12v outputs to come up with 15v from the power supply that could then be filtered to 12?

Using the -12 and the +3.3 should do that.

[fathead45]

i wish you luck with this. i didnt have much luck with mine. i used 350 watt ps and they didnt seem to want to put out the voltage i needed even for a 50 ct of pixels. its hit and miss for people.

[rjchu]

I'm not sure I see how this is possible unless the power supply is defective. I'm currently using the one I pictured below to power 10 RGB+W SuperStrips that are still on my lower roof eves and while it's not a very scientific test, that's 4 LED's (R,G,B,W) x 18 per strip x 10 strips = 720 LED's that this thing is driving simultaneously without issue - and yes I've tried them all on at once. This particular Micro ATX power supply is a Logisys 350 watt that's rated for 3.3v @ 30A, 5v @ 20A and 12v @ 12A. Seems like it should be fine to drive pixels, or in my case eventually pixel strips.

Or am I off/wrong here and need to make other arrangements?

Thanks,

-joni-

i wish you luck with this. i didnt have much luck with mine. i used 350 watt ps and they didnt seem to want to put out the voltage i needed even for a 50 ct of pixels. its hit and miss for people.

[rstehle]

I believe you are correct. I have a 400 watt version that I have been using for several years and it puts out plenty of 'juice'.

I'm not sure I see how this is possible unless the power supply is defective. I'm currently using the one I pictured below to power 10 RGB+W SuperStrips that are still on my lower roof eves and while it's not a very scientific test, that's 4 LED's (R,G,B,W) x 18 per strip x 10 strips = 720 LED's that this thing is driving simultaneously without issue - and yes I've tried them all on at once. This particular Micro ATX power supply is a Logisys 350 watt that's rated for 3.3v @ 30A, 5v @ 20A and 12v @ 12A. Seems like it should be fine to drive pixels, or in my case eventually pixel strips.

Or am I off/wrong here and need to make other arrangements?

Thanks,

-joni-

[miw01]

i wish you luck with this. i didnt have much luck with mine. i used 350 watt ps and they didnt seem to want to put out the voltage i needed even for a 50 ct of pixels. its hit and miss for people.

I've recently had some problems using PC PSU's it seems that some need a load on each rail (when multi rail) particularly 5 or 12.

I was just trying to use 12v on a PSU and unless I loaded the 5V Rail with to 0.5 A i.e. 2.5w bulb the 12v rail would not conduct!

[rstehle]

I've recently had some problems using PC PSU's it seems that some need a load on each rail (when multi rail) particularly 5 or 12.

I was just trying to use 12v on a PSU and unless I loaded the 5V Rail with to 0.5 A i.e. 2.5w bulb the 12v rail would not conduct!

The tutorial I followed when converting my PS mentioned putting a 10 ohm 10 watt resistor across one of the 5v leads and ground. Keeps a constant load on the PS.