capacitor

A capacitor is a device that stores an electrical charge when a potential difference (voltage) exists between two conductors which are usually two plates separated by a dielectric material (an insulating material like air, paper, or special chemicals). Capacitors block DC voltages and pass AC voltages. They are used as filters, AC coupling capacitors and as by-pass capacitors. They are also used in conjunction with resistors and inductors to form tuned circuits and timing circuits. A capacitors value C (in Farads) is dependent upon the ratio of the charge Q (in Coulombs) divided by the V (in volts). Common capacitors come in values of microfarads or Pico farads. Often you will have to convert between Pico farads and micro farads. A chart is provided below to assist in the conversion. For a list of capacitor terms defined: Click HERE. Measuring capacitance requires a capacitance meter. This is separate piece of test equipment. There are attachments for multimeters that allow measurement of capacitance directly. Also read this tutorial on how to test capacitors.
CAPACITOR Value Conversions:
Some capacitors may be marked in micro farads and others of the same capacitance value marked in Pico farads. One Pico farad equals one micro-micro farad. You may need to make conversions between the two equivalents.
Prefix
Power of 10
Example
Mili
10-3
.001
Micro
10-6
.000001
Nano
10-9
.000000001
Pico
10-12
.000000000001
Micro F = Pico FPico = uuf so; .01uf = 10000 pf .001uf = 1000 pf .005uf = 5000 pf .009uf = 9000 pf .0001uf = 100 pf .0005uf = 500 pf .0009uf = 900 pf

A capacitor marked 104M is a .001 uf +- 20% A capacitor marked 103M is a .01 uf +- 20% A capacitor marked 102M is a .1 uf +- 20%