Toggle switches are actuated by moving a lever back and forth to open or close an electrical circuit.  There are two basic types: maintained contact and momentary contact.

Maintained contact toggle switches maintain the position to which they are moved or actuated. Momentary contact toggle switches do not. Both types of toggle switches can use short (.5-in.), ball (<.75-in.), standard (.75-in.), or long (1.5-in) handles.

Specifications

Important specifications for toggle switches include dimensions, electrical ratings, terminal types, materials and features.

Physical Specifications

• Length or diameter
• Width
• Panel thickness

Electrical Specifications

• Maximum current rating
• Maximum AC voltage rating
• Maximum DC voltage rating
• Maximum power rating

Terminal Types

• Feed-through style
• Solder terminals
• Screw terminals
• Quick connect or blade terminals
• Surface mount technology (SMT)
• Straight PC pins
• Right angle PC pins
• Side PC pins

Materials

Most toggle switch bases and toggle switch actuators are made of plastic, thermoplastic, or metal materials.

Features

• Pilot light or illumination
• Imprinted markings
• Wiping contacts
• Locking mechanism
• Time delay
• CE certification
• CSA certification
• UL listing
• Dustproof
• Weather resistant
• Waterproof

Configuration

Maintained-contact toggle switches and momentary-contact toggle switches differ in terms of switch configuration.

Configurations for maintained-contact toggle switches are described below.

• ON/OF toggle switches have separate ON and OFF functions and work like light switches.
• Three-position toggle switches have a center position that may or may not perform an OFF function.

Switch functions for momentary-contact toggle switches include the following.

• Momentary ON describes contacts which interrupt the circuit when the toggle switch is in the normal, open (NO) position.
• Momentary OFF describes contacts which establish a circuit when the toggle switch is in the normal, closed (NC) position.
• Alternate ON/OFF describes a switch where the first actuation turns the toggle switch ON and the second actuation turns the toggle switch OFF.
• Three-position momentary center-NEUTRAL toggle switches have a center position that can perform an OFF or NEUTRAL function.

There are several configurations for pole and throw toggle switches.

Single pole single throw (SPST) toggle switches make or break the connection of a single conductor in a single branch circuit. This switch type typically has two terminals and is referred to as a single-pole switch.

Single pole double throw (SPDT) toggle switches make or break the connection of a single conductor with either of two other single conductors. These switches usually have three terminals and are commonly used in pairs. SPDT switches are sometimes called three-way switches.

Double pole single throw (DPST) toggle switches make or break the connection of two circuit conductors in a single branch circuit. They usually have four terminals.

Double pole double throw (DPDT) toggle switches make or break the connection of two conductors to two separate circuits. They usually have six terminals are available in both momentary and maintained contact versions.

A normally open (NO) toggle switch has contacts that are open or disconnected in their unactuated (normal) position.

A normally closed (NC) toggle switch has contacts that are closed or connected in their unactuated (normal) position.

Standards

EIA-480 - Toggle switches

EIA-520D000 - Sectional specification for toggle, paddle, and rocker switches

EIA-520DAAA - Detail specification on 1 pole toggle switches

Image credits:

Heilind Electronics, Inc. | RAFI GmbH & Co. KG