Today we will cover the next in our series of the basic electronic component, the capacitor.

A capacitor is used to store and release electrical charge in a circuit. When the voltage in the circuit is higher than what is stored in the capacitor, the capacitor will allow current to flow in and the capacitor will be given a charge. When the voltage in the circuit drops lower than what is stored in the capacitor it will dis-charge, releasing its stored charge into the circuit. This will cause the voltage in the circuit to temporarily raise.

This is extremely useful as some components, such as electric motors, use more power when they are first activated then when they are already active which can cause a voltage drop in the circuit that can have negative effects on other components in the circuit.

Capacitors help level out these fluctuations in voltage.

There are 2 main types of capacitors, Polarized and Non-Polarized. I will not go into a great deal of detail regarding the differences, but in a nut shell non-polarized capacitors have no implicit polarity and can thus be connected to the circuit either way, whereas polarized capacitors have a defined + and – terminal and must be connected to the circuit corresponding to its terminal polarity. This also means that non-polarized capacitors are suited for use with AC, but polarized capacitors are strictly only suited for DC as they experience large leakage if the voltage is inverted across its terminals as is the case with AC, which can cause the capacitor to overheat.

The capacitance of a capacitor is measured in Farad(F). For most circuits you will likely work on microFarad(µF) and picoFarad(pF) sized capacitors will be utilised.

Here are the schematics used to represent both polarized and non-polarized capacitors:

Polarized Capacitor

            Non-Polarized Capacitor