subject: Different Types of Electrical Switches [print this page] Different Types of Electrical Switches Different Types of Electrical Switches
Electrical switches are devices that can make, break or divert an electrical current. These may be mechanical, electrical or electronic, and are composed of two or more contacts, mounted on an insulated structure, which can be moved in and out of contact with each other. As the use of electric and electronic items has expanded, wide ranges of switches have been developed in numerous styles, including many varieties of toggle, keyboard, dial, push button and rocker configurations.
Electrical switches fall into two basic categories: power switches and signal switches. Power switches are used to energize or de-energize an electric load and are commonly found on light switches, power tools and appliances. Load-break switches are used in high voltage power systems, which require arc interrupters, or safety devices that detect electrical arc and interrupt the current, similar to the function of a circuit breaker.
Signal electrical switches are set to react to circumstances that require a preset response. The thermostat on a heater or air conditioner is one example. When a certain temperature is reached, the thermostat will turn another electrical switch on or off. Signal switches are also found in freezers, refrigerators, and sensor-triggered security lights. Some security lights are activated by photoelectric light controls, which are triggered when the natural light has dimmed or brightened to a certain level.
The most common electrical switches are mechanical switches, which make or break an electrical contact when some force, either manual or magnetic, is applied to move the switch to an on or off position. Toggle switches have a lever, which is pushed or pulled, like the common light switch. Power windows and locks in automobiles use rocker switches, which rock back and forth when pressed. Keyboard switches are found on computers, washers, stoves and other devices with push controls.
Electronic switches are electrical switches that do not have mechanical contacts, but use semiconductor devices. These switches apply electrical control signals to terminals on the switch that opens and closes the contacts. Touch plate devices, soft-touch controls and motion detector switches are frequently electronic. Some electronic safety switches mounted on food processing equipment use radio frequencies, which will interrupt the power when a safety door is opened. Electronic switches are available in a vast range of configurations such as toggle, rocker, push button, rotary, slide, and reed and relay switches.
