Gateway Parts

computer power supply capacitor?

I am trying to salvage parts from a computer power supply, but there are 2 rather large capacitors that between them have over 200 volts stored. It has been unplugged for a while and the voltage has not gone down. I dont want to damage the capacitors, components, or myself. How would I discharge them? i checked them with a mulitmeter

Public Comments

1. Use a resistor of any value larger than 100 Ohms and place the resistor across the terminals of the capacitor. For a 100 Ohm resistor, the capacitor should discharge completely in a matter of seconds, for a larger valued resistor it will take a bit longer. If you want to, you could even take a screwdriver and short out the capacitor terminals. This will probably generate a big 'pop' and a spark, but discharging the capacitor 'all at once', will not hurt the cap. .
2. Use a resistor - a large one, maybe 100K. Do the math to check how much current will flow and what power the resistor can handle. Be carefull.
3. How do you know they still have charge on them? Find a 10k or so resistor and touch it across each cap for a few seconds. Hold it with pliers. If you use anything smaller than 10k, use a power resistor, despite what others say. Shorting with a screwdriver can cause damage. edit by this time they have probably discharged themselves.