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Old 05-18-2019, 02:10 AM   #33
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Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 2,817
Default Re: DPS5020 dual power supply build

In the case of my first supply, with the single DPS module, earth ground is not actually connected to the negative side of the bridge rectifier - it's only connected to the chassis of the transformer and that's it. By "earth-ground" I refer to the third prong of the IEC 13 plug on the back, so I don't know if my meter would actually measure anything between this prong and GND. I now realize I should've probably tied GND and that earth terminal together - seems industry-standard. Even better add those Y-caps+1meg resistors you suggested.

I noticed on some Samsung TVs I worked on that cold GND (GND of the 5/12/etc. power rails of the SMPS) is connected directly to the metal frame which is then tied to the earth prong on the mains lead with no Y cap in-between. I definitely remember seeing blue Y-caps on SMPS boards, somewhere in the corners near the metal mounting lugs but I can't remember for sure where they go. I think they're between HOT GND and earth (chassis).

Last edited by Dannyx; 05-18-2019 at 02:16 AM..
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