Types of Electric Switches

Cam switches have a plastic disk (cam) over which contoured surface a mechanical follower moves, controlling the contacts. The cam is attached to and rotated by a handle shaft.

Double pole double throw (DPDT) switches open or close the connections of two conductors to a pair of separate circuits. DPDT switches, which usually have six terminals, can be set to maintain contact, alternate contact or have momentary contact.

Double pole single throw (DPST) switches open or close the connection of a pair of circuit conductors in a single circuit. DPST switches usually have four terminals.

Dual inline package (DIP) switches are a set of small-sized ON-OFF switches. DIP switches are used in place of jumpers and in such electronics as garage door openers, personal computers and paintball marker electro-chips.

Enabling switches are similar to safety switches , except they are manually operated. Enabling switches are designed to protect workers in more hazardous environments in which there is heavy machinery.

Key lock switches are activated by use of a fitting key. The key is turned to one of several positions, triggering the switch.

Lever switches are activated by turning a lever that is connected to a pivot point. Lever switches typically have three positions.

Limit switches are utilized in monitoring and for the control of machinery and industrial equipment. Limit switches come in many different sizes and configurations.

Maintained switches stay in the selected position when the handle is released.

Miniature switches are used in applications that require compact mechanisms, such as handheld equipment.

Multiple limit switches are used for the positioning and control of industrial equipment and machinery.

Pressure switches convert pressure changes to electrical functions.

Pushbutton switches are so called due to their activation method, which is usually in the form of a plunger that, when pushed down, opens or closes the switch. The configurations of these mechanical switches can be single-pole single-throw (SPST), single-pole double-throw (SPDT), double-pole single throw (DPST), double-pole double throw (DPDT) or solid state.

Reed switches feature two contact blades, called ferromagnetic reeds, which are encapsulated in glass. The reeds close when exposed to a magnet.

Rocker switches are electric switches that are activated by rocking the switch to one side.

Rope pull switches are triggered when there is tension in the safety cable. Rope pull switches provide safety and monitoring contacts in the printing, food processing and pharmaceutical industries.

Rotary switches have contacts that are arranged in a full or partial circle, which means the mechanism that selects the contact must be turned. Rotary switches, which may be manual or automatic, are used in such applications as automobile distributions or ignition switches.

Safety switches feature integrated actuators, which serve to protect both equipment and personnel. This is done by monitoring the positions of movable components.

Single pole double throw (SPDT) switches, also referred to as "three-way switches," open or close the connection of one conductor with one of two other conductors. SPDT switches often have three terminals and are sometimes used in pairs.

Single pole single throw (SPST) switches, also called a "single-pole switches," open or close the connection of one conductor in a single circuit. SPST switches usually have two terminals.

Snap action switches are designed to very quickly move their contacts from one location to another. Mouse buttons and appliance settings use such switches.

Toggle switches have only two positions. Light switches and the caps lock key on a computer keyboard are examples of toggle switch applications.