Generic s-500-12 testing and results

[AussiePhil]

The ongoing test series - this time it is a generic brand 500w smps in the 350w form factor we are all so used to.
This is a 12v, 42A rated unit.
Back story: I wanted to source a 12v SMPS for use on the test bench outside and wasn't prepared to wait the long lead time from Aliexpress, searched on Amazon and found this unit and it was delivered in 3 days. it will be used largely for testing and had to be the 350w form factor for vertical racking in place.

The amazon list heading is

DIGISHUO DC 12V 42A 500W Power Supply Adapter Transformer Switch AC 240V to DC 12V 42Amp Switching Converter LED Driver for LED Strip Light CCTV Camera Security System (12V 42A 500W)​

So just another generic supply with suspect specs and not much info


It has a fan and it seems to be on all the time despite the written notice


So test setup looks like: and in this photo we had 34 Amps being drawn


In the software we are running a soak test that comprises 5 steps. 10 -> 20 -> 34 -> 20 ->15 for 30 seconds each on repeat.

34A, 400w is the limit of the electronic load but it does conveniently fall at the 80% load point for this smps.

at 408w from the supply it needs 487w ac input making this unit 83.3% efficient, compared to the publish spec for a MW LRS-350-12 at 85% this stacks up quite ok.

Results of the soak test later on today with a pass fail ranking

Cheers
Phil

 

[AussiePhil]

Results time:
PASS

Four and a bit hours of constant use - between 23% and 80% of full rated current.
Yes it got warm to hot but it's nothing out of the ordinary to be fair.

at 34A (80%) the efficiency figure was above 83%, the supply had to drop 80w in heat.

Thermal images - the ambient temp was 30c and above.



In the one taken at 17:54 the load had been removed and whilst still warm within the couple minutes was already approaching ambient temp.

If you added a fan that blew across the hot spot area this would be fine for use in an enclosed case with external ventilation.

 

[AussiePhil]

Ok, just ran a test sequence that was essentially just a rainbow butterfly on the 400cnt string from https://auschristmaslighting.com/th...tage-drops-for-ws2811-5v-square-pixels.14521/
at about 30 minutes from the end i tweaked it to have a fade away from white/yellow to black to vary things a little.
We know that 100% white had @16A draw
The butterfly effect averaged around 9A
The two effects average around 8A
The power in Wh was 43 = 8.6A total average
So using 8.6A / 16 we get around 54% average power consumption.
this is high end for a single prop and a full show would be less

Lets call it from 50% to 60% load on a supply that is sized to provide full 100% white loading at max.

Soak testing would be valid for this supply from 250W to 300W (21A to 25A)

TLDR: this supply is fine.
Cheers
Phil