SPDT stands for Single Pole Double Throw, a switch that consists of three terminals and connects the source terminal and one of two output terminals.An SPDT switch allows for an “ON/ON” configuration, which means the switch’s input terminal is always completing one of the two possible circuits that the switch controls.
- If the switch is in the “ON-1” position, the connection between the input terminal is established with the first output terminal, thus completing the first circuit.
- If the switch is set to “ON-2,” the second output terminal establishes the connection with the input terminal, thus completing the second circuit.
Features of SPDT Switch
- It has three terminals: common, normally open (NO), and normally closed (NC)
- The common terminal is connected to either the NO or NC terminal depending on the switch position
- It can be actuated manually or by a mechanical or electrical signal
- It can handle moderate to high current and voltage ratings, depending on the specific model
Working of SPDT Switch
- In its default position, the common terminal is connected to the NC terminal
- When the switch is actuated, the common terminal is connected to the NO terminal instead
- This action can be used to switch between two different circuits or to control the direction of current flow in a circuit
- The switch can be spring-loaded so that it returns to its default position when the actuating force is removed
Advantages of SPDT Switch:
- It is less cost
- It is reliable for most the applications
- It can work with high voltages & currents.
- High switching currents let the device control relays, pumps & drive motors.
Applications
- Switching between two power sources
- Controlling the direction of current flow in a motor or other electromechanical device
- Selecting between two different signal sources in a circuit
- Circuit protection and safety, such as shutting off power to a device in case of a fault or overload.
Overall, SPDT switches are versatile components that can be used in a wide range of electrical and electronic applications.