DC to DC PSU project.

[lincoln2012]

Hey folks. I was unable to find a DIY tutorial for a dc to dc power supply so I decide to open a tread here and see if i can get some help.

With today's energy efficient APUs we don't need a 500 watts to run it, so why we can't find a decent 150 watts low profile PSU out there?

I was looking at the "pico psu" but they are overpriced.

If enough experienced people decide to jump in, we can design a very good and affordable unit.

So, what you guys think? Lets do it?

[lincoln2012]

Re: DC to DC PSU project.

I was reading about the pico psu and it looks like that the +12 volt feed comes directly from the DC source you use. So if your brick is not the bet quality it may fry your motherboard.

Now this bad boy here seems to be a better design. It delivers 130 Watts continuous and still small enough to be used with a ITX mobo on a very small system.

Looking at the pictures it does not look like rocket science to design and build something around this idea..

[Colt45ws]

Re: DC to DC PSU project.

They make wide input PicoPSUs that can take up to 24 or 26VDC input. So all the outputs are getting filtered. Testing showed the best configuration was to use a wide input model with like a 19V supply for cleanest output.

[mariushm]

Re: DC to DC PSU project.

Yes, but the picoPSU is only capable of about 4-5A on 12v and a handful of amps on 3.3v and 5v.

picoPSU is not overpriced considering the integration, the pcb is probably 4-6 layers, it's two stacked pcbs... but the form factor has its limitations.

Once you increase the size, it's easier, but then you already have solutions out there. Nothing stops you from getting a power supply with dc-dc converters inside and analyze the dc-dc converter boards to reverse engineer the circuits.

For a few amps, you don't even have to go that far, there's plenty of switching regulator chips on digikey that you can get for a few dollars and just do the circuits in the datasheet.

Here's for example how simple the dc-dc converters are:

http://www.techpowerup.com/reviews/I...II_600W/4.html

http://www.techpowerup.com/reviews/I...es/in_VRMs.jpg
http://www.techpowerup.com/reviews/I...s/in_VRMs2.jpg

And these are made for 10-20 amps, you can cut down the fets and the inductor in half if you make a system for ~ 150w

[tom66]

Re: DC to DC PSU project.

I was playing around with a computer motherboard (plus HDD) and found it was quite stable down to 9V on the 12V bus. Beyond that it would work but was occasionally unstable.