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Funny power supply.

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jurgen36

Technical User
Nov 7, 2003
436
AU
I fitted a Super Flower 800 watt supply in one of my machines. I noticed if you unpluged the mains cord the computer continued working for about 5 minutes or so before it shut down. It is a beautifully made supply with four exhaust fans build in. I decided to find out what caused the strange behaviour. After opening the supply all looked normal. However as I looked more closely I found that the 12 volt line had a 3.3 farad capacitor on the output line, alternatively the 5 volt line used a 10 farad capacitor and the 3.3 volt line used a 20 farad capacitor. I am talking about farad or milions of microfarads not microfarads. If you switch the computer off the power supply fans continue spinning for over 30 minutes even with the power cord disconnected and the memory LED stays on. This could be quite dangerous, if somebody unplugs the supply and starts working on the machine the 5 and 12 lines will still be powered up for a long long time and might blow components.I suppose they used supercapacitors to bridge momentary power losses. But I do believe they should advise about this feature to prevent accidental dammage. Regards

Jurgen
 
Farads? They must be the size of jam-jars!
 
No not at all, supercapacitors are very small indeed, I checked up on them on google, they use them now in missiles as powersuplies etc. The ones in the unit are made by NEC. Regards

Jurgen
 
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