this post was submitted on 01 Oct 2024
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Bought a new PC, and I was measuring its consumption out of curiosity. I noticed something weird (to me): when the PC is off (in fact, I completely disconnected the PSU and did the same test), there is quite some current running in the power cable to the PSU (0.15A).

Further measures showed a power factor of (almost) zero, and I can actually measure a capacity of 2uF across the PSU ac input.

I did the same thing on an older PC I have, and there is no current / capacity. So what would the reason of a capacitor across the mains on the input be in a PSU?

PS: the PSU is a Thermaltake Toughpower GF A3 1050W

Edit: I found some official measurements for this specific PSU: https://www.cybenetics.com/evaluations/psus/2249/ that have 40W standby apparent-power by design

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[–] mattreb@feddit.it 2 points 2 months ago

Thanks for the interesting write-up!