First unit built, and all voltages check out OK!

Thanks wiretap!
- Alex

You're welcome 😀

Nice!!

How’s it work on the mobo?

Does it seem like it has too much leverage when moving the cable around? Maybe damaging the mobo? Guessing it’s short enough to not be an issue?

I wonder if we can make it even shorter yet by moving the power switch header to the side and making the atx connector solder to the front and back edge of the board. If atx connectors are hard to find, these could be cut.

Probably not worth messing with though, looks like a great product as is!

I just finished testing all 5 boards, and they all work. Next will be testing with a motherboard.

- Alex

since the AT connector needs to be swapped anyway on many boards, what about a adapter that solders directly to the board? are there pin headers of the proper size for a right angle mount?

I'd worry about the leverage on the solder joints when plugging the ATX in that case, I think a plugged adapter is better in that regard cause you can plug it in afterwards, unless you put the ATX connector on a cable maybe.

The leverage isn't bad, just train the cable. But, those solder points for the power connector are pretty large. I wouldn't worry about a light cable hanging off it damaging anything.

Probably going to order one of these soon, figured I'd take a crack at making it even shorter! 😀

Hope you don't mind Wiretap. 😀

Double check me here, how's it look?

-I connected the two -5v pins. it shouldn't hurt anything if two -5v supplies are in parallel. and also, if my psu has -5v I can avoid having to install the regulator.

-I also made some adjustments here and there that I think should make it handle even more current.

-Added silk under the fet to protect those masked lines more from the fet tab. Not needed but doesn't hurt.

Looks good. 😀 You can adjust the thermal spoke width in the fill settings to give yourself some more current carrying capacity.

wiretap wrote on 2022-04-29, 10:42:

Looks good. 😀 You can adjust the thermal spoke width in the fill settings to give yourself some more current carrying capacity.

Thanks! I just updated the file again. (small tweaks).

Yeah I made them larger actually, I noticed the power planes were solid, I think it's okay that they are spoked. I see someone above had a little trouble getting the solder to flow. So I set all planes to thermal relief mode. But I did increase the thermal spoke width.

Most applications won't exceed 5a 12v tops and 10A or so maybe 12 on the 5v tops. I base this on my atx2at readings. and that's loaded with cards and ram and dual processor. Someone using this witha pico psu and low power parts is looking at a fair amount less than that.

This of course should work great with a normal psu also.

I've never set up a pcb to be manufactured fully assembled. can we do that here? Do you know how? or is it already ready to go?

are there horizontal L pin headers that we can use in place of the male and female AT connectors (direct solder option)? I can't seem to find one.

Edit: Made a order for the pcb! (pcb only)

Note: error cap position is reversed.

New version:

Those traces passing under the fet bugged me 🤣

Also here is a better view of the layers:

3d

I wonder if it’s worthwhile to implement a PicoPSU replacement on a larger board? It’d be really nice to just be able to plug in DC power and have all the regulators on a single device.

- Alex

ajacocks wrote on 2022-05-11, 14:24:

I wonder if it’s worthwhile to implement a PicoPSU replacement on a larger board? It’d be really nice to just be able to plug in DC power and have all the regulators on a single device.

- Alex

It seems like this kinda goes hand in hand with smaller cases also, because if using a ATX case there isn’t much point not to just use a full size psu.

I had a thought though, it may be possible to plug more than one pico psu into a single mobo.

If we can find some PNs for male and female vertical connectors we can make a splitter that pluggs into this allowing multiple pico psus

Just noticed redundant trace between 5v atx pin and 5v led.

The via already connects it to 5v plane. So trace could be removed 🤔

wiretap wrote on 2022-02-21, 03:09:

Yea, don't buy the Chinese knockoff Pico PSU's. The real PicoPSU can output roughly the same amount of amps on both the 12V and 5V rails. They obviously shouldn't be used in late AT systems, but rather for Pentium MMX and prior AT or SBC systems.

Can you drop a link to the best one to get? I got one but it was wired all weird and won’t even turn on it seems 🤣

Just an idea, to make similar adapter in the same format but 24pin atx -> 20pin atx that would also give -5v to mbo from modern atx psu. I'd buy that, been searching for a long time but only seen atx-at adapters...

Jura Tastatura wrote on 2022-05-11, 18:22:

Just an idea, to make similar adapter in the same format but 24pin atx -> 20pin atx that would also give -5v to mbo from modern atx psu. I'd buy that, been searching for a long time but only seen atx-at adapters...

Make a thread, find the plugs and kicad footprints and if I get time I’ll try and throw it all together.

Jura Tastatura wrote on 2022-05-11, 18:22:

Just an idea, to make similar adapter in the same format but 24pin atx -> 20pin atx that would also give -5v to mbo from modern atx psu. I'd buy that, been searching for a long time but only seen atx-at adapters...

Its not a PCB but easiest way to do what you need is get a fully wired 24 atx to 20 atx cable and solder in a 7905 and two capacitors, someone made a small pcb for the components and it's here on the forum but I'm too sleepy to find the link to it.

also, I think the title of this thread should be changed to AT pico adapter :-p