Power Supply News about pico psu?

Valantar

SFF Guru
Jan 20, 2018
1,043
811
You're welcome.

No worries, no promises I'll have spares.. building a new mini AM4 system :)



Nice! Those look like the ones I have except thinner wires.

Got two running a firewall



and server/NAS



with two of them and stress tested them above 250W without issue.



They are running open though in a cool environment until I finish the cases for them.

A big part of that is likely the 94% efficient platinum PSU I use to power them.




Looks like if you upgrade the wires you should be fine. Be sure to test everything!

So you're running both off an ATX PSU, just off .. PCIe power cables or some such? Guess that should work (and you'd be guaranteed ripple/noise specs within ATX spec), but otherwise the AC-DC PSU shouldn't have any effect on the heat output or quality of the DC-ATX unit. Soldered cables vs. tiny socketed ones makes a big difference, though, as most small sockets/connectors are only rated for a few amps and can quickly overheat if loaded heavily. Also, how did you generate those loads - CPU stress testing? Your DC input cables look nice and beefy, but the outputs to the EPS and peripheral cables looks about as flimsy as what mine looks like. What gauge is the wire (should be printed on the sleeving)?
 

encore2097

Caliper Novice
May 13, 2019
24
7
So you're running both off an ATX PSU, just off .. PCIe power cables or some such? Guess that should work (and you'd be guaranteed ripple/noise specs within ATX spec), but otherwise the AC-DC PSU shouldn't have any effect on the heat output or quality of the DC-ATX unit. Soldered cables vs. tiny socketed ones makes a big difference, though, as most small sockets/connectors are only rated for a few amps and can quickly overheat if loaded heavily. Also, how did you generate those loads - CPU stress testing? Your DC input cables look nice and beefy, but the outputs to the EPS and peripheral cables looks about as flimsy as what mine looks like. What gauge is the wire (should be printed on the sleeving)?
Its an commercial 12V only PSU, not ATX.

16AWG copper on the input and 18AWG copper or better for the peripherals. Cant trust the rating on the outside, only way to know for sure is to measure the actual wire with calipers. Thats often why the cheaper versions catch fire..

The closer the input is to spec, the less filtering/ "work" the picoPSU has to do so the less heat is output. Some picoPSUs are designed for use in cars so they have beefy filters to handle input surges like when starting an engine.

Prime95 for CPU / ram / system loads + something for GPU or your favorite tool.

Its been running for two+ years @ 100% uptime so I'm confident with the stability.
 

Thehack

Shrink Way Wielder
Creator
Bronze Supporter
Mar 6, 2016
2,451
2,970
J-hackcompany.com
Its an commercial 12V only PSU, not ATX.

16AWG copper on the input and 18AWG copper or better for the peripherals. Cant trust the rating on the outside, only way to know for sure is to measure the actual wire with calipers. Thats often why the cheaper versions catch fire..

The closer the input is to spec, the less filtering/ "work" the picoPSU has to do so the less heat is output. Some picoPSUs are designed for use in cars so they have beefy filters to handle input surges like when starting an engine.

Prime95 for CPU / ram / system loads + something for GPU or your favorite tool.

Its been running for two+ years @ 100% uptime so I'm confident with the stability.
12v does little or no real filtering, which is what most of this picopsu are. And filtering does not really create heat output either.

The primary cause of heat of a 12v Pico is as the mosfet has a non zero resistance that creates a voltage drop. The more current you are pulling the more heat it puts out. More expensive mosfet are beefier and lower resistance.
 

encore2097

Caliper Novice
May 13, 2019
24
7
12v does little or no real filtering, which is what most of this picopsu are. And filtering does not really create heat output either.

The primary cause of heat of a 12v Pico is as the mosfet has a non zero resistance that creates a voltage drop. The more current you are pulling the more heat it puts out. More expensive mosfet are beefier and lower resistance.
maybe these will help:


you can also look at the ICs on the picoPSU pull up the datasheet and see what they do or make a mini SPICE simulation!

The Art of Electronics is another fantastic resource!
 

Thehack

Shrink Way Wielder
Creator
Bronze Supporter
Mar 6, 2016
2,451
2,970
J-hackcompany.com
maybe these will help:


you can also look at the ICs on the picoPSU pull up the datasheet and see what they do or make a mini SPICE simulation!

The Art of Electronics is another fantastic resource!


1. Filtering is not a dcdc conversion, nor is it a buck circuit. Filtering describes an LC circuit which does not produce heat (that one can easily measure, we can assume it produces no heat) . There is no IC involved in a filter circuit. It's a series of inductors and capacitors. You stated it has to work harder to filter a noisier output and produces more heat.

2. The primary rail of a picopsu is 12v. The 12v is produced by the acdc converter. This is the rail that is required to meet certain ripple specs.

3. The primary rail, 12v, is not switched (in the sense of switching DC DC circuit) , not dcdc converted, no buck circuit on the 12v. All 12v picopsu has the 12v go through a simple mosfet circuit, controlled by the IC, which has a simple on/off state.

4. This on/off state is where the losses creates most of the heat.

I'm not sure why you're trying to flex online resources while displaying a lack of understanding of DC circuit and how picopsu works.

You are referring these to someone who specs these picopsu to be manufactured and can read schematics.
 
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