A capacitor is a device that stores an electrical charge or energy on its plates. These plates are placed very close together with an insulator in between to prevent the plates from touching each other, and a type of dielectric. A capacitor can carry a voltage equal to the battery or input voltage. Usually a capacitor has more than two plates depending on the capacitance or dielectric type.Once charged the discharge rate can be influenced by another source. This action can create oscillation, or be used for electronic timing. The rate in witch the capacitor charges and discharges can be used to create a filter, or limit unwanted noise. There is lots more we can do with capacitors too.
HOW TO TEST THE CAPACITOR:
There are various methods for testing the capacitors. To short list, I would prefer to use one of the following two methods:
By ESR meter or by multimeter. Assuming that you would not be having the ESR tester just try to test it with the analog or digital meter just to get and idea whether it is defective or not. To test the capacitor do the following:
- Power OFF the device, disconnect it from the mains and wait for 15 minutes.
- Open or desolder one of the legs of the suspected capacitor.
- Take an analog or digital multimeter and set the range on Mag Ohms.
- Touch the probes of multimeter on each side of the capacitor legs and watch the dial (Polarity does not matter in this case).
- The needle of the analog meter or the digits of the digital meter will jump high and then comes back slowly. Reverse the probes and see if this happens again. If this is the case the capacitor is OK.
- If no reading or Zero is found the capacitor is open and is defective. Replace the capacitor.
- If the reading goes high, it is shorted and is defective. Replace the capacitor.
Hope that works. Thank you for visiting Fixya.