Good day folks. A while back, I started building a bench power supply (long story - see it here ). I noticed something about the pre-built line filter I wanted to use and it got me thinking whether it's a good idea to use it or not, at least in my particular case.
If you zoom in and look at the schematic on the label, the potential problem I see is the earth terminal connected to L and N via the 2 Y caps. I've seen this setup in virtually all of these and even some SMPS board may have this arrangement (though I'm not sure about this), so it's probably safe overall and makes perfect sense on paper, but won't this setup cause a problem if the wall outlet this is plugged in is not earthed ? Where I live, this is a very common occurrence - no earth prong on the plugs or the ones that do have it are simply not connected, so the earth pin is floating on devices which actually use it ! Won't this cause the earth prong (and the entire case) to float at half the line voltage and be a shock hazard ? I imagine the current would be quite low, but could still zap components like FETs and Op-amps if this was used to power a soldering iron or in this case, my bench supply.
If you zoom in and look at the schematic on the label, the potential problem I see is the earth terminal connected to L and N via the 2 Y caps. I've seen this setup in virtually all of these and even some SMPS board may have this arrangement (though I'm not sure about this), so it's probably safe overall and makes perfect sense on paper, but won't this setup cause a problem if the wall outlet this is plugged in is not earthed ? Where I live, this is a very common occurrence - no earth prong on the plugs or the ones that do have it are simply not connected, so the earth pin is floating on devices which actually use it ! Won't this cause the earth prong (and the entire case) to float at half the line voltage and be a shock hazard ? I imagine the current would be quite low, but could still zap components like FETs and Op-amps if this was used to power a soldering iron or in this case, my bench supply.
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