A really simple electrical circuit may consist of a power source (such as a battery), two connecting wires and a light bulb. One of the wires would be connected to one side of the battery and one side of the bulb, the other wire would be connected to the other side.
If the connections are made correctly then the current will flow. The circuit is then deemed to be closed. The light bulb should then light up. To make the bulb light, the current flows from the power source down one wire to the light bulb. It then flows from the light bulb on the other wire back to the power source. If the wires are discconnected, the current cant flow. The circuit is then said to be open or broken. Usually a circuit is opened by a device such as a switch, fuse or circuit breaker.
The two main classifications for circuits are series and parallel. A series circuit consists of two or more elements connected end to end (one after another) so that the current flows through each element in turn before returning to the power source. A parallel ciruit consists of elements next to each other but not chained together. The current flow is divided amongst them all.
When two circuit components are connected in series, their effective resistance (impedance if the circuit is being fed alternating current) is equal to the sum of the separate resistances; the current is the same in each component throughout the circuit. When circuit components are connected in parallel, the total resistance is less than that of the element having the least resistance, and the total current is equal to the sum of the currents in the individual branches. A battery-powered circuit is an example of a direct-current circuit; the voltages and currents are constant in magnitude and do not vary with time. In alternating-current circuits, the voltage and current periodically switch direction with time.
A normal electrical outlet provides alternating current. Electrical machinery aswell as lighting ciruits both employ alternating currents.
Many other devices, including computer systems, radios, and television sets, must first convert the alternating current to direct current. That is done by a special internal circuit usually called a power supply.
A digital circuit is a special kind of electronic circuit used in computers and various other devices.
Magnetic circuits are analogous to electric circuits, where magnetic materials are regarded as conductors of magnetic flux. Magnetic circuits can be part of an electric circuit; a transformer is an example.
If you are having troubles with your electricity circuits then call the emergency electrician hackney