What does Dpst mean on a switch?

Double Pole Single Throw
A Double Pole Single Throw (DPST) switch has four different terminals and is often used to connect two source terminals to their respective output terminals (but never to each other). A DPST switch can be used in an “ON/OFF” configuration, where its terminal pairs are either connected (“ON”) or not connected (“OFF”).

How does a DPST relay work?

A relay, however, behaves in a different way. Since it is operated by an electromagnet, when the magnet is de-energized, the switch will go back to its original position. For a DPDT relay, that means that when the control circuit is off, the relay will turn on either circuit A or circuit B.

How many circuits can a DPST relay control?

It can be an On-On switch or On-Off-On. DPST again means it controls two separate circuits but it only has one On position.

When would you use a DPST switch?

A DPST switch is often used to switch mains electricity because it can isolate both the live and neutral connections. A pair of on-on switches which operate together (shown by the dotted line in the circuit symbol). A DPDT switch can be wired up as a reversing switch for a motor as shown in the diagram.

Which is the double pole single throw DPST relay?

The Double Pole Single Throw DPST relay is the equivalent of 2 SPST switches (NO Normally Open and NC Normaly Closed) and can be used to switch 2 different loads. As you can see in the schematics above if we use a NO DPST relay the contacts will be closed only if voltage is applied to the coil.

How many terminals does a DPST switch have?

The DPST switch, for example, has four terminals, but it is a DP, not a 4P switch. Throw refers to the extreme position of the actuator: ST switches close a circuit at only one position. The other position of the handle is Off. DT switches close a circuit in the Up position, as well as the Down position (On-On).

What happens to the contacts on a DPST relay?

As you can see in the schematics above if we use a NO DPST relay the contacts will be closed only if voltage is applied to the coil. In the schematics above if we use a NC DPST relay the contacts will be closed without voltage being applied to the coil and opened when we apply voltage to it.

How does a DPDT relay change direction of rotation?

When voltage is applied to the coil then the relay switches and now T1 (plus) is connected to contact 2 (and 3) and T2 (minus) is connected to 4 (and 1) therefore the motor is changing the direction of rotation.