Light switches are a common feature of our daily life, you perhaps use them without giving them much thought especially how they work. Yet these simple devices control lighting all over from offices to homes. Having this knowledge allows you to better appreciate their work, take care of them and even understand their setup. So how does a basic on/off light switch work
The basics of an electrical circuit
At the core of the working principle of on/off light switches is an electrical circuit. It is the pathway that allows electrical current to flow, and everything, including the light bulb, is part of the circuit. The electrical circuit is a continuous loop taking electricity from the source to the lighting device and back again. If there is a break anywhere in the circuit, the current does not flow.
Parts of an electrical circuit
A basic electrical circuit is made up of the following parts;
- Power Source: this is the source of electricity; it could be a battery or your house’s main power supply.
- Conductors: these are materials usually metals like aluminium and copper which allow electrical current to pass through them easily.
- Load or device: this is the item that uses the electricity in this case the light switch.
- Switch: A switch serves as the control mechanism in an electrical circuit. It can break a circuit or complete it.
How a Switch Works in an Electrical Circuit for On/Off Light Switches
As the name suggests, On/Off light switches are based on the control of electrical switches. In the Off position, the circuit is not complete because the switch has broken it. The off position creates a barrier in the circuit preventing electrical current from flowing.
If you think of electrical circuits as a bridge then the Off position breaks the bridge, which means no electricity gets to the device, i.e., the bulb so it stays off.
On the other hand, in the On position, the switch completes the circuit, and using the example of the bridge, it completes the bridge allowing the electrical current to get to the device in this case the light bulb thus turning it on and you get illumination.
Components of a light switch
So, what makes up a light switch? The control mechanism of the electrical circuit comes with several components which add to its working. The main ones include;
- Terminal Screws: The light switch comes with two screws one on either side. One screw is for power coming from the source, while the other is for power going to the load or device, the light bulb.
- Toggle Lever: This part is the most familiar one to people. It is the part you use to turn the light on and off. It connects or breaks the circuit, which allows you to turn the light on or off by pressing either side of the lever.
- Internal Contacts: The switch does not work alone in completing the electrical circuit. It uses internal contacts. These are inside the switch and are what connect or break the circuit, decided by the position of the toggle lever’s position.
Thus, in the end, the working of a light switch comes down to the simple mechanism of breaking or completing the circuit. Even with the advancement of technology, the light switch maintains a simple working mechanism.
