A switch is a device that is used to control current flow in an electrical circuit. A simple switch provides electrical connection between two terminals when a conductor connected to one terminal is brought into contact with another terminal. There are two types of pole switches, namely: the single pole and the double pole switch. We’ll tell you more about these switches and their differences in this article.
|Single Pole Switch||Double Pole Switch|
|Has two terminals for SPST (single pole, single throw) or three for SPDT (single pole, double throw)||Has four terminals for DPST (double pole, single throw) or six for DPDT (double pole, double throw)|
|Controls a single circuit||Capable of controlling two circuits simultaneously|
A single pole switch usually refers to a single pole, single throw switch (SPST). It is a switch that provides a simple connect or disconnect capability across two terminals. It is commonly used for on/off applications such as light switches.
A double pole switch may refer to a double pole, single throw switch (DPST). It is simply the combination of two SPST switches simultaneously controlled by a single mechanism.
Single Pole Switch vs Double Pole Switch
The main difference between a single pole switch and a double pole switch is related to the number of terminals they have and the number of circuits they control. A switch is said to be “open” when there is no current flow between two terminals and is “closed” when the current flows from one terminal to the other. A common application of a switch is to turn the room lights on or off.
A single pole switch can either be an SPST (single pole, single throw) switch or an SPDT (single pole, double throw) switch. An SPST is a switch that has two terminals, while an SPDT has three terminals. It is a switch that toggles connection between one common terminal to either of two other terminals.
A double pole switch, on the other hand, is essentially a switch that allows or disallows current flow between two distinct lines or circuits at the same time. It can either be a DPST (double pole, single throw) switch or a DPDT (double pole, double throw) switch. A DPST has 4 terminals, while a DPDT has 6 terminals. This is essentially two SPDT switches that are controlled by a single mechanism.
Single pole switches control only a single circuit whereas double pole switches are capable of controlling two circuits simultaneously.