Finding Value of Capacitors

Finding Value of Capacitors

Electrolytic capacitor

Electrolytic capacitors are polarized capacitor (+ve and –ve) and

generally used when very large capacitance values required. There are two terminals +ve and –ve , negative terminal usually indicated by black line with arrows or small rectangle.  Improper connection (+ve terminal of capacitor to negative terminal of supply or vice versa) may cause fires and explosion, so we should be careful when connecting electrolytic capacitor.

Since values are normally marked on capacitors in terms of Micro Farad (uF) with voltage we can easily find values, here it is 4700uF and 16V.

Polyester capacitor value

Generally the values, voltage and tolerance are marked on the body of capacitor; however it uses different methods for example the above shown capacitor written 100K100V, that means 100x1000pf value would be 100000pf or 100nf or 0.1uF/100v.

Another example

This capacitor is labelled as 47nK the value is 47nf , if it is n47 = 0.47nf, 4n7 = 4.7nf.

Another example

2A103J represents 100v 10X10^3 pf with 5% tolerance,   that is equal to 10000pf = 10nf = 0.01uf.  The reference table for voltage and tolerance is shown below.

1H = 50V
2A = 100V
2D = 200V
2E = 250V
2G = 400V
2J = 630V

Disk/Ceramic capacitor

Ceramic capacitor generally uses 3 digits like  102, 103, 101 for indicating its value and values in term of Pico farad.

 In ceramic capacitor if the three digits are ABC, then the value would be AB*10^C Pico farad.

            

Here the digit is 104 that means 10*104pf = 100000pf = 100nf = 0.1uf.

Another example

Value would be 22*10^4pf = 220000pf = 220nf = 0.22uf.