A Wiltronics’ Guide to Toggle Switches

Jump to Section

Have you ever heard of toggle switches? They are a type of switch used in many electrical applications for circuit control. But what exactly are they?

This post will cover the basics of toggle switches, including how they work, their uses, and types.

What Are Toggle Switches?

Toggle switches are a type of electrical switching device. They control the flow of electric current through a circuit using a “toggle”. This toggle rotates on an axis to make and break an electrical connection. The mechanism also provides physical control over electrical functions and comes in two separate operations:

• ON/OFF
• Open/closed or up/down

In each position, it latches into place and remains there until moved back. The toggle itself is rigidly mounted onto an insulating surface. There are two leads for power connected to two terminals at opposite ends of the switch.

The term “toggle switch” is due to the resemblance of the switch’s lever to that of the toggle used in clothing.

The structure

Depending on the type of toggle switch you have, it may consist of the following components:

• Lever. The user can press the lever in the operating direction to switch ON/OFF. Levers are often made of resin, but larger units are metal to increase durability.
• Spring. This part is loaded inside the level. It pushes outwards and is always in contact with the base.
• O-ring. The circular rubber parts that seal the connections between the base and the case.
• Plunger. The resin component that is attached to the button of the lever. It is always in contact with the bottom of the base, limiting the movement range of the lever.
• Moving armature. The U-shaped contact embedded into the lever. Its tip moves with the lever and the terminal in between activates the ON state of the switch.
• Case. The case protects the internal components of the switch. It also supports the lever through the hole on the upper surface.
• Base. Utilised along with the case, protecting the internal components of the switch.

How Do Toggle Switches Work?

The working principle of a toggle switch, as mentioned, is straightforward. You can activate it manually with a lever or the “toggle” and flip it ON and OFF.

When the switch is turned OFF, the circuit is disconnected and no power will flow through the device. To turn it back ON, you must push down the toggle, reconnecting the current to flow through the device. Each switch is designed differently depending on its intended use in a circuit.

Usually, the switch will remain in position until manually moved once more. But there are momentary switches that included an attached spring. This feature pulls the actuator back to its starting point once released.

Different Types of Toggle Switches

Toggle switches are available in multiple sizes and designs for various settings. They also offer different levels of contact resistance and internal contact point materials. Below are some of the common toggle switch models:

1. ON-ON toggle switches (changeover switches)

ON-ON switches control two devices, with each position of the switch activating one of the two. They combine a standard click position with a spring-loaded one. This will snap back if not held in position.

2. ON-OFF toggle switches (positive ON-OFF switches)

The most basic toggle switch design! It provides simple, binary ON-OFF control for power supplies. This switch type also makes an audible clicking noise when moved from one position to the next.

3. ON-OFF-ON toggle switches

This type of toggle switch is a variation of the ON-ON design. It adds a third, neutral-off position in the centre. In ON-OFF-ON switches, the off position is the default resting position. Both ON positions will click back to this once released.

4. Momentary toggle switches

The term momentary refers to switches fitted with a spring. Most toggle switches have a momentary variant, such as the ON-OFF-ON.

Contact configuration

There are four basic toggle switch designs, featuring poles and throws. Poles are the individual power supplies controlled by each switch. Throws, in contrast, are the different positions available to the switch, such as ON and OFF.

• Single Pole, Double Throw (SPDT). An SPDT changes the direction of voltage, switching a single current on two devices. Either activating or deactivating them.
• Single Pole, Single Throw (SPST). SPSTs are basic ON-OFF switches. A single incoming current is directed towards a single device in an open/closed circuit.
• Double Pole, Double Throw (DPDT). A DPDT switch is in effect two ON-OFF switches operating with one another. It enables the voltage supplied to a certain device to be varied. Both ON-ON or ON-OFF-ON switches are DPDT.
• Double Pole, Single Throw (DPST). DPSTs allow two different circuits to be switched ON or OFF simultaneously. This permits easy control of two devices operating alongside each other.

Toggle Switches vs Rocker Switches

Toggle and rocker switches are types of switching mechanisms used in electrical devices. The main difference between them is their form and the way they are operated.

Toggle switches have a lever that slides to one side or the other to control an electrical device. In contrast, rocker switches are typically round or oval-shaped. They also control an electrical device but operate in a different manner.

Toggle switches typically provide more precise control than rocker switches. The size of the former can vary depending on the application it is being used for.

The Bottom Line

Toggle switches let you turn ON and OFF the current in a device, thanks to their switching functions. Having knowledge of this switch will prove useful while working with circuits. It always helps to be aware of these crucial yet overlooked components!