Conductors and Insulators Conductors are materials that allow electrical current to flow. Insulators are materials that do not allow electrical current to flow. In a circuit with and alternator current, a diode lets forward current through, but it blocks the reverse current. This is called rectifying the current. Fuses and Circuit Breakers Fuses and circuit breakers are used to protect electrical systems from allowing too much current to flow.
Lamps Turn electrical energy into heat energy and produce light.
Various types of lamps are used in the automobile. Relays Relays act as switches that are turned on and off by a small current. They can allow large current to be switched on and off in a circuit. Resistors Resistors are used to cause a drop in voltage in circuits. They are used to control current flow.