Linear ATX power supply

[Crom]

nice job Kenneth, if you are able to you really should get rid of that fan as removing it will cure a few potential problems - vibration, odd magnetic fields and noise on the power line. When I did it, it wasn't a night and day change but well worth it. I replaced it with a large heatsink but I did have one of the lower power-rated CPUs.

 

[SGK]

analog-sa

What did you do for the -12V? Did you simply leave it unconnected?

 

[Crom]

I'm sure analog-sa will be along in a minute but maybe this will help. -12v is pretty much legacy for the ATX spec and many motherboards will boot up comfortably without it. However, it's pretty much test yours and if it does you're in luck. If not, then you'll need -12v.

 

[analog_sa]

Precisely. My MB does not require -12v.

 

[SGK]

Thx. I have an ASRock Z87E-ITX mobo and am building a linear PSU. I'm hoping I can simply leave the -12V disconnected. I guess I could test with an extension between the ATX socket and the existing picoPSU, simply cutting the -12V supply and seeing if it will boot...

 

[jborden]

Logic circuit for Linear to ATX

In case there is interest to come close to meeting the ATX specification, this circuit may help to supply the logic. Into this circuit Linear supplies can be plugged. Zener diodes ensure each supply is in range in case, e.g. batteries, are being used. When power enabled, the Omron relays switch the power on.

View attachment linear-atx-logic.pdf

 

[SGK]

I finished my project in this regard. I built 3 'super regulator' power rails capable of 5A+. I also built an ATX power control board based on the TPS3510. This chip monitors the supplies and coordinates with the computer motherboard for PWR-ON sequencing etc. This board includes a pre-amplifier for measuring the quality of the supply rails. I attach the circuit for ATX PSU control and a pic of the completed board, plus a pic of the power rails on their heatsink.

 

[jborden]

I finished my project in this regard. I built 3 'super regulator' power rails capable of 5A+. I also built an ATX power control board based on the TPS3510. This chip monitors the supplies and coordinates with the computer motherboard for PWR-ON sequencing etc. This board includes a pre-amplifier for measuring the quality of the supply rails. I attach the circuit for ATX PSU control and a pic of the completed board, plus a pic of the power rails on their heatsink.

Nice, that circuit is simpler than mine. In regards to using FET vs. relay to switch current: any big advantage? Assuming we want as low noise as possible (not that its needed for ATX but for the sake of discussion), which switch is best? Let's say we want to switch signal path, FET vs. relay? are the Omron quiet (electrically)?

 

[randytsuch]

I finished my project in this regard. I built 3 'super regulator' power rails capable of 5A+. I also built an ATX power control board based on the TPS3510. This chip monitors the supplies and coordinates with the computer motherboard for PWR-ON sequencing etc. This board includes a pre-amplifier for measuring the quality of the supply rails. I attach the circuit for ATX PSU control and a pic of the completed board, plus a pic of the power rails on their heatsink.

I'm impressed, very nice project.

I was way lazier, I found a motherboard that doesn't care about the power on sequencing. I made supplies for +5 and +3.3, and used an off the shelf for 12.

 

[jrling]

I finished my project in this regard. I built 3 'super regulator' power rails capable of 5A+. I also built an ATX power control board based on the TPS3510. This chip monitors the supplies and coordinates with the computer motherboard for PWR-ON sequencing etc. This board includes a pre-amplifier for measuring the quality of the supply rails. I attach the circuit for ATX PSU control and a pic of the completed board, plus a pic of the power rails on their heatsink.

Very impressive work.
Would you be offering them for sale or were they one-off for you?

Thanks
Jonathan

 

[SGK]

Hi. Thanks. I'm not planning to start a commercial production. I have a few spare boards for the ATX Power Control board and ver 1 of my inrush limiter which I can sell to you. For the reg rails I can post Gerber files for the board I made and you could order more boards. Not sure if that helps you at all.

Btw some more pics here and here

 

[analog_sa]

Wow, Mlytics on the regulator boards, nice

 

[thanhvo31]

Good day, @SGK

I have plan to build a music server base on Mainboard ASRock Q1900M and a Linear ATX PSU.

Through several topics here I knew you had successfully built your own PSU.

So how about newest version? Is it rated 100W.
Could you share your design or some spares set?
Thanks and regards

 

[SGK]

Hi. I have not changed the psu circuit I built for my audio server. It is based on a MOSFET pass transistor and details can be found in a thread call "adventures with 5A regulator circuits" or something like that. I went on to explore other circuits based on Darlington BJT transistors here because the actual MOSFET performance was unlikely to match its modelled performance.

Thermal considerations for Fairchild SDIP bridge rectifiers

But this design was constrained to 1A. You could remove the pre-regulator for greater current capability (if you check SOA of the pass transistor).

I'm not sure if I have spare boards as I am in New Zealand for the next few months while all my stuff is in Miami.

 

[oneinsect]

Hi. Thanks. I'm not planning to start a commercial production. I have a few spare boards for the ATX Power Control board and ver 1 of my inrush limiter which I can sell to you. For the reg rails I can post Gerber files for the board I made and you could order more boards. Not sure if that helps you at all.

Btw some more pics here and here

Dear SGK

Can you post the gerber files for the board?

Thank you for the work!!