What is SPST Switch? Single Pole Single Throw Switch


An SPST switch or Single Pole Single Throw switch is a switch that has only one input and only one output. It just connects and disconnects those single input and single output to each other. The SPST switch can control only one electrical circuit by making or breaking contacts with one position. It is very simple in nature. It just turns on or off the circuit. It does not have any current bypassing interchanging function.

Here, you can see the symbol of SPST switch

SPST Switch Symbol, Symbol of SPST Switch



Here, you can see the circuit diagram of SPST switch to understand its working principle. 

SPST Switch Circuit Diagram, SPST Switch Wiring Diagram and connection


Here in the above wiring diagram of SPST Switch, you can see the switch is connected in series with the battery and a light. as it allows only one input and one output, so the one terminal of the battery(positive terminal) and one terminal of the led light(positive is connected to the SPST switch). The negative terminal of both battery and light are connected directly.


The working principle and function of the SPST switch is very simple. When it closed its contacts the circuit will be closed and turned on. So the LED will be glow. When it open its contacts the circuit will be open and turned off. So the led also be turned off.

You can see the application and uses of the SPST switch in your house switchboard. Yes, the switches used in your house electrical switchboard is used for turning on or off the lights, fans are the examples of SPST switch. Remember one-way switches are SPST, but two-way switches are SPDT means single pole double through.

SPST switches are available in the market in many types of switches such as toggle switch, piano type switch, etc. So, it does not imply that a toggle switch or piano-type switch is working in other principles. They also work in SPST or SPDT principle.

SPST Switch Use

1. It can be used to light On/Off purpose.

2. It can be used to On/Off the power supply.


Read Also: 

Thank you for visiting the website. keep visiting for more updates.

What is SPST Switch? Single Pole Single Throw Switch What is SPST Switch? Single Pole Single Throw Switch Reviewed by Author on 12/11/2021 Rating: 5