The 2013 El-cheapo Power Supply Roundup

[c_hegge]

Thanks for the information. I'll add that to the reviews next week when I'm back at home and on my computer and not my tablet. I want too sure about the Zumax, simply because Topower-built units usually have "TOP" markings on the transformers, which the Zumax lacks.

[Schafskopf]

there are quite a lot of topower-made units that lack these markings (for example this one or this - you can also see that asiax-capacitors can be found in topower-built units).

by the way, do you remember the coodmax unit from last year, which was quite similar? to me it looked like topower back then, but I was unsure because I never saw them use Evercool fans. But now I'm quite sure, knowing that Zumax belongs to Topower and these units are definitely not made by Leadman, Casing Macron (who also build Zumax power supplies) or XHY-Power (who made some other Topower-branded units).

[c_hegge]

I've added the OEM information to the Bliss and Zumax.

I also noticed that the Coodmax from last time also has "ZU" markings on the input filtering coil, which points to Topower/Zumax as being the OEM. I have added that information to it as well. I'm sure the Zumax would have the same markings on the input filter coils if there were any installed.

[LongRunner]

The power factor on the Cooler Power looks bad for even passive PFC. In fact, it's no better than you would get without PFC, so I suspect they've faked it again (obviously more accurately than in some other units).

In regard to the secondary rectifiers in forward topology, whether you have to de-rate them, and to what extent, depends on how they're connected (no simple rule there).

Also, the coils in one side of the mains have a different role from those in both sides, although I can imagine many PSUs getting away without the former.

[LongRunner]

Has anyone else noticed that, on the input to the Infinity, there's a blue wire from the mains switch to the PCB and a brown wire in neutral (they should be the other way around)??? And why would they use Nichicon HM of all series??? The fan from the same unit has this on the label:

BOMD

Way to hint at the true (lack of) quality.

[c_hegge]

Has anyone else noticed that, on the input to the Infinity, there's a blue wire from the mains switch to the PCB and a brown wire in neutral (they should be the other way around)???

Yeah, I saw that. Maybe they were just trying to re-use whatever pieces of scrap wire they could find?

And why would they use Nichicon HM of all series???

Maybe the low ESR was probably needed to keep the ripple in check. Or maybe the manufacturer was able to acquire them cheap? I really don't know.

[LongRunner]

NSCom fails at math:

The combined limit for +3.3V and +5V consumption is given as 300W, but their individual ratings only add up to 285.8W.
17A from +12V is not 218W, it's 204W.
-5V at 0.6A is 3W, not 6W.
-12V at 1A is 12W, not 14W.
+5VSB at 3A is 15W...

[c_hegge]

Yup. I've seen that several times before.

[Wester547]

In the GX850, which +12V rectifier failed? The one on the high side or the low side? Or both?

[LongRunner]

The one on the high side or the low side?

As far as I can tell, c_hegge's just confused about the formula to calculate the actual current handling...