A double pole double throw (DPDT) switch is a type of switch that can control two circuits at once. This type of switch is commonly used in electrical systems and is often found in devices such as power tools, appliances, and control panels.
What is a DPDT switch?
A DPDT switch is a type of switch that has two sets of contacts that can control two separate circuits. Each set of contacts has a common terminal and two other terminals that are connected to separate circuits.
The switch has a lever or rocker that can be moved to connect the common terminal to either of the other two terminals, thus connecting one circuit or the other.
How does a DPDT switch work?
When the lever or rocker is in one position, the common terminal is connected to one of the other terminals, and the first circuit is energized.
When the lever or rocker is moved to the other position, the common terminal is connected to the other terminal, and the second circuit is energized.
A DPDT switch is often used in situations where two circuits need to be controlled independently, but where it is also desirable to have the ability to control both circuits at the same time.
DPDT Switch Wiring Diagram
Before wiring a DPDT switch, it is important to ensure that the switch is rated for the voltage and amperage of the circuits that it will be controlling.
The DPDT switch wiring diagram below shows how the switch can be wired to control two separate circuits, A and B. Each circuit has a load, which can be a light, motor, or other device that is powered by the circuit.
| Terminal | Function |
|---|---|
| 1 | Common |
| 2 | Circuit A, Terminal 1 |
| 3 | Circuit A, Terminal 2 |
| 4 | Circuit B, Terminal 1 |
| 5 | Circuit B, Terminal 2 |
Here is how to wire a DPDT switch for circuit A:
- Connect the positive (+) wire from the power source to terminal 2 of the switch.
- Connect the negative (-) wire from the power source to the load for circuit A.
- Connect the load for circuit A to terminal 3 of the switch.
Here is how to wire a DPDT switch for circuit B:
- Connect the positive (+) wire from the power source to terminal 4 of the switch.
- Connect the negative (-) wire from the power source to the load for circuit B.
- Connect the load for circuit B to terminal 5 of the switch.
When the lever or rocker of the DPDT switch is in one position, circuit A is energized. When the lever or rocker is in the other position, circuit B is energized. When the lever or rocker is in the middle position, both circuits are off.
FAQs
What is the difference between a SPDT and a DPDT switch?
A single pole double throw (SPDT) switch has one set of contacts that can control two separate circuits. A DPDT switch has two sets of contacts that can control two separate circuits.
Can a DPDT switch be used for DC circuits?
Yes, a DPDT switch can be used for DC circuits, but it is important to ensure that the switch is rated for the voltage and amperage of the circuits that it will be controlling.
What is a latching DPDT switch?
A latching DPDT switch is a switch that requires a momentary action to change positions and then stays in that position until it is again activated.
Can a DPDT switch be used as a three-way switch?
No, a DPDT switch cannot be used as a three-way switch, which requires a different type of switch.
Where can I buy DPDT switches?
DPDT switches can be found at many electronics stores, hardware stores, and online retailers.
