- 5th June 2008, 18:23 #1

- Join Date
- Jun 2006
- Posts
- 258
- Helped
- 16 / 16
- Points
- 2,929
- Level
- 12

## how to safely discharge a capacitor

How to discharge Large Capacitor Safely ?

:)

- 5th June 2008, 18:23

- 5th June 2008, 19:00 #2

- Join Date
- Jan 2008
- Location
- Bochum, Germany
- Posts
- 27,739
- Helped
- 8750 / 8750
- Points
- 171,292
- Level
- 98

## how to discharge a capacitor safely

With a current limiting resistor of sufficient power capacity.

- 5th June 2008, 19:00

- 6th June 2008, 16:36 #3

- Join Date
- Mar 2006
- Location
- Culiacán, Sinaloa, Mexico
- Posts
- 479
- Helped
- 68 / 68
- Points
- 3,875
- Level
- 14

## how to discharge a capacitor

Adding to the response of FvM at small current in the resistor, the safer or long live to the capacitor.

- 6th June 2008, 16:36

- 12th June 2008, 08:02 #4

- Join Date
- Nov 2007
- Posts
- 33
- Helped
- 1 / 1
- Points
- 1,155
- Level
- 7

## discharge large capacitor

you should have a rsistor parallel to your capacitor and this resistor is usually called the bleeder resistor since the stored energy is being discharge to the resistor this in turn prevents voltage spike during start-up.

- 12th June 2008, 10:31 #5

- Join Date
- Jul 2007
- Posts
- 110
- Helped
- 0 / 0
- Points
- 2,055
- Level
- 10

## how to discharge a large capacitor

The larger value of resistor, the slower the capacitor discharged and vice versa, but with too small value of resistor, the capacitor discharges so fast causes explosion sound (it doesn't mean something bad with capacitor), the proper value is about 100Ohm

- 12th June 2008, 19:05 #6

- Join Date
- Dec 2005
- Posts
- 36
- Helped
- 4 / 4
- Points
- 1,497
- Level
- 8

## safely discharge capacitor

Originally Posted by**smiles**

The 'safe' thing to do is to calculate one for your situation. The calculation will need to know how fast of discharge is needed (in addition to the capacitors specs). Some can wait an hour, some may need in < 1 second... ??