DPDT (Double Pole Double Throw) switches are commonly used in a wide range of electronic circuits. These switches are used to control the direction of current flow in a circuit, and to switch between two different circuits. A DPDT switch has six terminals, but for most applications only four are used. In this article, we will discuss the wiring diagram of a 4 pin DPDT switch in detail.
What is a 4 Pin DPDT Switch?
A 4 pin DPDT switch has four terminals, which are labelled as A, B, C and D. The switch has a lever or knob that can be moved to different positions, and this changes the connection between the terminals. The switch has two poles and two throws, which means that it can switch between two different circuits. When the switch is in one position, it connects one set of terminals, and when it is in the other position, it connects a different set of terminals.
What are the Different Types of DPDT Switches?
There are two main types of DPDT switches – Centre-Off and Non-Centre-Off. In a Centre-Off switch, the lever or knob of the switch can be moved to three different positions – On-Off-On. This means that the switch has a central position where both circuits are disconnected. In a Non-Centre-Off switch, the lever or knob of the switch can be moved to two different positions – On-On. This means that the switch does not have a central position.
Wiring Diagram of a 4 Pin DPDT Switch
The wiring diagram of a 4 pin DPDT switch is shown below:
| Terminal | Function |
|---|---|
| A | Common Terminal 1 |
| B | Normally Open 1 |
| C | Normally Closed 1 |
| D | Common Terminal 2 |
| E | Normally Open 2 |
| F | Normally Closed 2 |
The switch has two poles, which are connected to two different circuits. Each pole has a common terminal, a normally open (NO) terminal and a normally closed (NC) terminal. When the switch is in one position, the common terminal is connected to the NO terminal, and when it is in the other position, the common terminal is connected to the NC terminal.
How to Wire a 4 Pin DPDT Switch?
The wiring diagram of a 4 pin DPDT switch is simple, but it is important to follow the correct wiring procedure to ensure that the switch works correctly. The following steps outline the wiring procedure:
- Identify the common terminals of the switch. These are the terminals that are connected to the centre of the switch. In a 4 pin DPDT switch, the common terminals are A and D.
- Identify the NO and NC terminals of each pole. In a 4 pin DPDT switch, the NO terminals are B and E, and the NC terminals are C and F.
- Connect one pole of the switch to one circuit. The common terminal of the pole should be connected to the positive wire of the circuit, and the NO terminal should be connected to the load. The NC terminal should be left unconnected.
- Connect the other pole of the switch to the other circuit. The common terminal of the pole should be connected to the negative wire of the circuit, and the NO terminal should be connected to the load. The NC terminal should be left unconnected.
- Test the switch to ensure that it works correctly. Move the lever or knob of the switch to different positions and check that the circuits are switched correctly.
FAQs
What is a DPDT switch used for?
A DPDT switch is used to control the direction of current flow in a circuit, and to switch between two different circuits. It is commonly used in circuits that require the ability to reverse the direction of a motor or to switch between different modes of operation.
What is the difference between a DPDT switch and a SPDT switch?
A DPDT switch has two poles and two throws, while a SPDT switch has one pole and two throws. This means that a DPDT switch can switch between two different circuits, while a SPDT switch can only switch between two different states of a single circuit.
What is the difference between a Centre-Off DPDT switch and a Non-Centre-Off DPDT switch?
In a Centre-Off DPDT switch, the lever or knob of the switch can be moved to three different positions – On-Off-On. This means that the switch has a central position where both circuits are disconnected. In a Non-Centre-Off DPDT switch, the lever or knob of the switch can be moved to two different positions – On-On. This means that the switch does not have a central position.
Can I use a DPDT switch to control a motor?
Yes, a DPDT switch can be used to control the direction of a motor. The switch should be wired so that one pole of the switch is connected to the positive wire of the motor, and the other pole is connected to the negative wire. The common terminals of the switch should be connected to the positive and negative wires of the power source. When the switch is in one position, the motor will rotate in one direction, and when it is in the other position, it will rotate in the opposite direction.
Can a DPDT switch be used with AC circuits?
Yes, a DPDT switch can be used with AC circuits. However, it is important to ensure that the switch is rated for the voltage and current of the AC circuit.
