How to Discharge a Capacitor

Video Transcript

"How to discharge a capacitor. A capacitor is essentially a battery that is designed to hold voltage and release it very quickly. Because of this a capacitor can actually be very dangerous if not handled properly. So you want to make sure that you take some safety precautions when you are working around capacitors or if you need to discharge one. You do not by any means want to accidentally short the positive and the negative sides of the capacitor, it can cause the capacitor to explode, it can also cause arcs or shorts and could also cause electrocution. So we will talk a little bit about the correct way to discharge a capacitor. This is a relatively small capacitor that as you can see has been charged to a little over fifteen volts. Now when I remove the power from the capacitor, you can see on the meter just the power draw from the meter alone is causing the capacitor to start to drain. But obviously we don't want to sit for an half an hour waiting for it to drain. So the best bet is to find something that will dissipate the energy into heat, light, sound, whatever. And one such item that can be used for a capacitor of this size is a twelve volt automotive bulb. And all you need to do is to take the capacitor and touch the ground to the case of the light, and the power to the power of the light. And you will see the meter automatically drops down to zero, if it comes back up a little bit that's not a big deal that's just a residual charge. But this capacitor is now safe to handle. If you have a larger capacitor, something in the hundreds of microfarads that is being used say in a stereo installation of the light, you might want to use something that draws a little bit more power. Like a small electric motor or an amplifier or even a heater element, something like that. But all you are looking to do is to safely dissipate that energy into another form, in this case light. And that is the best way to do it."