Capacitors Explained for Engineers
Introduction to the Capacitor in Electrical Engineering
We can think of capacitors are short term ‘charge-stores’. In other words, capacitors just store charge inside them. A capacitor consists of two metal plates separated by a layer of insulating material called a dielectric.
There are 2 types of capacitor:
Electrolytic capacitors. These hold much more charge and must be connected with the correct polarity, otherwise they can explode.
Non-electrolytic. These hold less charge and can be connected either way round in a circuit.
How Does a Capacitor Work?
When two conducting plates are connected to a battery, electrons move towards one plate. The positive plate loses electrons , eventually leaving both plates with equal and opposite charge, +Q and -Q. When a capacitor is charged, we say that the capacitor has charge Q.