1. Ceramic Capacitor
This type is very popular non polarized capacitor that is small and inexpensive but has poor temperature stability and poor accuracy. It contains a ceramic dielectric and a phenolic coating. It is often used for bypass and coupling applications. Tolerances range from +/-5 to +/-100 percent, while capacitances range from 1 pf to 2.2 uF, with maximum voltage rating from 3 V to 6 kV.
2. Mylar Capacitor
This type is a very popular non polarized capacitor that is reliable, inexpensive, and has low leakage current but poor temperature stability. Capacitances range from 0.001 to 10 uF, with voltage ratings from 50 to 600 V.
3. Mica/ Mika Capacitor
This type is an extremely accurate device with very low leakage currents. It is constructed with alternate layers of metal foil and mica insulation, stacked and encapsulated. These capacitors have small capacitances and are often used in high frequency circuits (eg. : RF circuits). They are very stable under variable voltage and temperature conditions. Tolerances range from +/-0.25 to +/-5 percent. Capacitances range from 1 pf to 0.01 uF, with maximum voltage ratings from 100 V to 2.5 kV.
4. Capacitor Readings
Examples : Capacitor Code 474
4 (first figure) and 7 (second figure) is significant figure and third number is 4 is multiplier (4 = 10.000)
So, Capacitor Code 474 = 47 x 10000 (pF / pico Farad) = 470000pF (pico Farad)
470000 pF = 470 nF (nano Farad) = 0.47 uF (micro Farad)