Lowyat.NET: Latest topics by kisuke_77

Huntkey X7 900W

kisuke_77 — Sun, 24 Jan 2010 09:11:01 +0800

This is perhaps the best Huntkey PSU so far, using full bridge MOSFET switch. Secondaries are all independently regulated ...
The review is here ... Travis has done a very good job.

http://www.itocp.com/htmls/47/n-647.html

Antec True Power New 750W

kisuke_77 — Wed, 22 Jul 2009 20:22:06 +0800

Awesome ... No wonder Seasonic is so famous in the US.

http://www.hardwaresecrets.com/article/766/1

PC Power and Cooling Silencer 910W

kisuke_77 — Tue, 07 Jul 2009 21:35:56 +0800

This is another great PSU built on Seasonic M12D platform. Awesome !
http://www.jonnyguru.com/modules.php?name=...=Story&reid=157

Coolermaster Real Power 450W

kisuke_77 — Sun, 17 May 2009 08:56:38 +0800

This is the coolermaster realpower 480W PSU made by AcBel. It failed after 5 hours of 90% load running test.
Took out the PCB and found both primary capacitor burst ... further investigations found 1 shorted MOV.

This PSU is non active PFC type. The primary capacitors are connected in series fed by output from rectifier when it is in 240V mode. Each capacitor has 1 resistor and 1 MOV connected in parallel. Resistor value for both capacitors are same. The purpose is to force equal potential across each capacitor. However I find resistor value is too high ~ 470k + 470k Ohm. It may not be able to compensate for the change of MOV and capacitor impedance ... IMO.

I have seen a lot of PSU designs. CWT made Antec 480W uses 47kOhm, Enhance made Silverstone 400W uses 47kOhm as well. I do not understand why AcBel uses so high value ... Could it be they want to maintain the PSU hold time while using lower capacitance ? ( because resistor will discharge the capacitor voltage ).

( 1 ) The Capacitors
[attachmentid=968635]

( 2 ) Electrolyte leaked ...
[attachmentid=968642]

( 3 ) Coolermaster RealPower 450W
[attachmentid=968646]

( 4 ) Up close of the capacitors ( Panasonic 200V, 820uF )
[attachmentid=968650]

( 5 ) The shorted MOV
[attachmentid=968651]