A Complete Guide to Toggle Switches

What are Toggle Switches?

Toggle switches are a type of electronic switch, one of the most basic and widely used electrical components. Electronic switches provide on-off control for electrical circuits by interrupting the flow of current or allowing it to resume. This is achieved by removing a metal contact from the terminal (endpoint of a circuit) or bringing the two back into contact.

When the contact is connected, the circuit is closed - live - electrical current can flow through and the attached device will turn on and operate. Then when the contact is moved away again the flow of current is broken, the circuit becomes open and the device is switched off.

Toggle switches feature a manually operated hinge, handle or lever mechanism - called a toggle - which moves from one position to another. In each position, it will normally latch into place and remain there until moved back.

Toggle switches are actuators - devices that switch a machine on or off. They are similar in function to rocker switches, but the latter feature a see-saw shaped button that swings from one position to another and are sometimes classed as a type of rocker switch.

Toggle switches are also known as joystick switches and toggle power switches. They are versatile devices and can be used with almost any electrical application.

Toggle Switch Applications

The toggle switch has a multitude of functions, from the simple (switching a kettle device on or off) to the complex (controlling multiple high voltage circuits).

By far the most familiar form is the light switch - so unobtrusive and yet so central to everyday life.

You will also find toggle switches in:

• Domestic, commercial and industrial power points

• Air conditioning systems

• Many types of industrial and electrical equipment, from conveyor belts to RCDs (residual current devices)

• Aeroplane control panels

• Vehicles

Toggle switches for cars allow drivers to quickly access headlights, indicator lights, and similar controls.

How Does a Toggle Switch Work?

Although available in different designs and configurations, the fundamental toggle switch design is as follows. An armature (component carrying electrical current) attached to the toggle moves when this is pulled, placing an electrical contact into a circuit or removing it, thereby activating or deactivating the circuit.

The switch will normally remain in position until manually moved once more, although momentary switches also include an attached spring which will pull the actuator back to its starting point once released.

Toggle Switch Types

As a basic electronic component, toggle switches are available in multiple sizes and designs for use in different settings.

The internal contact points are made from a variety of conductive metals, including brass, copper and silver, often plated with gold or nickel. Toggle switches also offer different levels of contact resistance (i.e. sensitivity to electrical current) and different maximum current ratings.

Let’s take a look at some of the key toggle switch models:

Other Toggle Switch Types

Toggle Switch with Cover

These switches feature covers or caps which serve various functions. They can protect the tips of the internal lever mechanism, prevent the switch from being activated accidentally or click the switch off when closed.

Flat Toggle Switch

The term flat toggle switch may refer to switches with a flat-sided toggle, or switches in flat metal plates for vertical or horizontal fitting (for example on walls or the sides of machinery).

LED Toggle Switch

LED toggle switches include a light-emitting diode (LED), typically in the tip of the toggle, which indicates the status of the switch (i.e. on or off).

A variety of matching accessories are available.

Mini Toggle Switches

These smaller toggle switches are also known as microswitches or snap action switches. They feature a sensitive spring-loaded toggle and respond to a small amount of applied force. The spring is energised by the inflow of current and this moves the contacts into place.

Principally designed for lower currents, microswitches are cheap and widely used in both domestic and industrial equipment, often as sensors to detect the position of a component for safety reasons. For example, they can be used to ensure a door or hatch is shut before power is activated and to trigger a shutdown of the current when the door or latch is reopened.

Mini toggle switches are used in:

• Microwave ovens

• Elevators

• Vending machines

• Industrial anemometers and control circuits

Microswitches are typically fitted in complex configurations. They are resistant to damage from electric surges or arcs.

Large Toggle Switches

Large toggle switches are designed to provide on-off control. They are used in settings where visibility and easy access are crucial - for example, aeroplane control panels. Some feature two linked toggles.

Contact Configuration

Beneath the surface complexity, there are four basic toggle switch designs, each featuring a different combination of poles and throws. Poles are the individual power supplies controlled by each switch, while throws are the different positions available to the switch - e.g. on and off.