Switches

By Doug Vanisky
A switch is a device that changes the route or direction of an electrical current or stream or data information. In their most basic design, a switch has two corrosion-resistant metal contacts that make contact to create a circuit, and separate to break the circuit. Switches come in a wide range of designs including:
Switches are used in electrical wiring, computer components, and to route data transmissions for voice, Internet, and network information.

Wall Switches

Wall switches are the most common type of switches that most people are familiar with. There are several common types.

Single-pole switches control one outlet or fixture from one location. They have two screws of the same color that hold two hot wires in place. The white wires are capped with screw-on wire caps or electrical tape, while the bare or green wires are the ground wires. Replacing these switches is easy, but first turn off the power source to the circuit. Unscrew the faceplate and the screws holding the switch in place, then pull the switch out gently and use a circuit tester to make sure there is no current. When you are sure the power is off, you can disconnect the switch box without removing any of the wires.

Three-way switches allow one light or electrical outlet to be turned on and off by two separate switches in different locations. This arrangement is increasingly used in homes and apartments to increase convenience. A normal switch has two terminals, but a three-way switch has three. Different manufacturers use different terminal configurations, but in a three-way switch the top terminal may connect to either of the two bottom terminals of the switches. Three-way switches also use a special Romex wire that has an extra red insulated wire that runs along with the black and white wires.

Dimmer switches are popular for the control they give over light levels. They allow light levels to be adjusted for different activities and can add to the atmosphere of an evening. By turning a knob or sliding a level, you adjust light levels from nearly dark to full lighting. Modern dimmer switches work differently than older ones, and instead of diverting energy into a resistor, they rapidly shut the light circuit on and off in order to reduce the energy current flowing through the circuit.

LAN Switches

Switches are used in computer networks in order to speed up processes. These switches allow different computers and connection points to communicate with each other directly in a smooth, efficient, and fast manner. LAN switches create a separate connection for each node in a company's internal network by allowing only two devices to communicate with each other at one time.