Electrical contacts Electrical contacts An electrical contact is an electrical circuit component found in electrical switches, relays, connectors and circuit breakers. Each contact is a piece of electrically conductive material, usually metal. When a pair of contacts touch, they can pass an electrical current with a certain contact resistance, dependent on surface structure, surface chemistry and contact time; when the pair is separated by an insulating gap, then the pair does not pass a current. When the contacts touch, the switch is "closed"; when the contacts are separated, the switch is "open". The gap must be an insulating medium such as air,
Armature (electrical) design of the machine and its performance, affecting such factors as commutation in a DC machine or the waveform of an AC machine. Armature wiring is made from copper or aluminum. Copper armature wiring enhances electrical efficiencies due to its higher electrical conductivity. Aluminum armature wiring is lighter and less expensive than copper. Armature (electrical) In electrical engineering, an armature is the power-producing component of an electric machine. The armature can be on either the rotor (rotating part) or the stator (stationary part) of the electric machine. The armature interacts with the magnetic field (magnetic flux) in the air-gap; the