What Is Double Pole Single Throw Switch – Working & Its Applications

Hello friends welcome to the new post. In this post, we will have a look at Double Pole Single Throw Switch. If you are an electrical engineer and an enthusiast of the electrical field, then you must have knowledge of different types of switches used in different circuits. The very commonly used switch is the double pole single throw switch, which is also called the DPST switch. It is mostly used in different electrical devices since it controls the current flow effectively. In this post, we will cover the different parameters of this switch like working, construction, and uses. So let’s get started DPST switch.

What is a Double Pole Single Throw Switch?

• The double pole single-through switch is a type of switch that is used to control the flow of electricity. It comes with two distinct inputs and two separate output terminals that are attached to different components of circuits.
• DPST switches comes with two positions ON and OFF that used for control power of circuitgry

Construction of DPST Switch

• The DPST switch was created with the use of two poles that are connected with two distinct input and output points. The poles are created with conducting material like copper and they are insulated from each other with the use of non-conducting material like plastic.
• The switch is functions with the use of a button or lever, that is connected to the poles with the use of mechanical linkage. When a switch has an ON state the two poles are attached helping the current to flow through the switch. In the OFF state, poles are not connected and the circuit has zero current flow

Working Principle of DPST Switch

• The working principle of the DPST switch is simple and easy. The switch is created to break or make a circuitry connection with the use of two poles and ON and OFF states control the current flow. When the switch is in an ON state, two poles are attached, and current flows through the switches.
• In the OFF state, poles are not connected and the current flow is zero.

Related: What is a Double Pole Switch? How its Work

Types of DPST Switch

• There are two main types of DPST switches that are commonly used in circuits

1. Toggle DPST Switch: This DPT type of switch operates with the use of a toggle or lever that is flipped to switch the circuit OFF and ON
2. Rocker DPST Switch: This switch is work through the use of a rocker or button that is pressed to switch circuitry OFF and ON

Advantages of DPST Switch

• It can control the current flow very easily and simple way.
• They are durable and structured and have the ability to handle a larger current
• Their installation and maintenance are easy
• It used in different circuits and appliances

Disadvantages of DPST Switch

• It needs a larger space to install then other switches
• They are more costly than other switches
• It can only be used to flow current in one circuitry

Applications of DPST Switch

DPST switches main application are explained here

• It is used to control the different industrial machines and motors
• It is used to turn off and ON lights in homes and offices
• It controls the switching process in different power sources in a circuit.
• It is used to control the heating element in the water heater
• It controls the oven temperature
• It is used to switch between two audio sources in the sound system
• It controls the current in battery charging circuits
• Work as safety switches in heavy machines
• DPST switch to control the current in different electronic devices like computers, TV and other appliances.

Read also: What is Double Pole Double Throw (DPDT) Switch

DPST vs SPST Switch

• DPST switch is compared with single pole single through switches called SPST switch. The main difference between the two switches is that DPST has two poles and SPST has one pole. It means that the DPST switch has ability to control the current flow in two circuits and the SPST control current in one circuitry

DPST Switch	SPST Switch
it comes with two poles	This switch has one pole
It can control the current in two switches	It can control current in one circuitry
It is used in different appliances like motors and machines for their power supply control, turning on and off lights and fans, controlling the heating element in a water heater switching between multiple power sources,	It is used in simple on or off applications like on and off the light or Fan

DPST vs DPDT Switch

The DPST switch is also compared to the double pole double throw switch, also known as the DPDT switch. The main difference between the two switches is that the DPST switch has two positions, while the DPDT switch has three positions. This means that the DPDT switch can control the flow of electricity in three circuits, while the DPST switch can control the flow of electricity in only two circuits.

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How to wire a Single Pole Double Throw (SPDT) switch.

 Gather Materials and Tools

Before starting the wiring process, we will need to get some materials and instruments that are listed here

• Single pole double throw switch
• Screwdriver
• Wire strippers
• Electrical tape
• Electrical wire

 Understand the Switch Connections

• As discussed above SPDT switch has 3 terminals COM, NO, and NC terminals. The COM terminals is used middle terminal and NO and NC are on the other sides.

 Wiring Process

1. First of all, turn off the power supply of the circuit where we have to work on
2. Strip the wire ends that we are going to use to wire the switch
3. With the use of a screwdriver connect one point of wire with the COM terminal of the switch
4. The other end of the wire connects with the power supply circuit
5. Make the connection of 2nd wire with NO terminal of the switch through the screwdriver
6. Make the connection of another end of 2nd wires to load that we have to control
7. Attach 3rd wire to NC terminals of a switch with use of a screwdriver
8. Connect the other end of 3rd wire with the ground or neutral wire in the circuitry
9. When all connections are completed wrap the tap around the connections to make insulation and avoid the short circuits
10. At last on the power supply and test the switch to make sure that it is working accurately

Safety Precautions while Working with DPST Switch

While working with DPST switches, some essential precautions must be followed to minimize the risk of any accidents. Some tips are explained here

• Always off the power supply before the connection or working with the switch
• Must use the proper instruments and tools
• Must use safety gear like gloves and safety glasses
• Ensure that you are following the wiring diagram given with the switch
• Do not exceed the highest current rating of the switch

How Does an SPDT Switch Work?

• The SPDT switch comes with three terminals or connections that are common terminal, COM, normally open or NO and normally closed terminal. When the switch is in off state circuit is attached to NC terminal and when the switch is in ON state circuit is attached to the normal open circuit. The COM point is always attached to either NO or NC point on the base of the switch position

 Uses of SPDT Switches

SPDT switches main uses are explained here

• In lighting circuits, this switch is used to control light with two different switches like at the top and lower side of the staircase
• In electronic circuits, SPDT is used between two input sources like a mixer or amplifier.
• In automotive circuits, it is used to switch different modes of operation like low and high beams  on the headlight

What is Single Pole vs Double Throw?

Single Pole	Double Throw
Number of Connections	2 (1 input, 1 output)	3 (1 input, 2 outputs)
Number of Positions	2 (on/off)	2 (on/on or off/on)
Function	Controls one circuit	Can switch between two circuits
Common Uses	Lighting, fans, outlets	Reversing motor direction, selecting between two power sources

 

 Advantages of SPDT Switches

The advantages of SPDT switches are explained here

• Versatility: SPDT switches are used in circuits that are controlled between two outputs
• Simplicity: The design of this switch is simple and easy to configure
• Durability: SPDT switches are created with high-quality materials which can withstand the hard conditions

Spdt Switch Diagram

• In the circuit diagram, the switch is off-state. The circuitry is attached with a normally closed NC point which means that the circuit is not completed and zero current flowing. When the switch is at on state. the circuit is connected to the normally open terminal that makes the circuit complete and helps the current flow.
• The common terminal is always attached to either the NO or NC terminal on the base of the position witch

What is an example of a Single Pole Double Throw switch?

• An example of a single pole double through the switch is a light switch that controls lights in the room with two different points.  This switch is known three qat switch since it needs three connections but it is a single pole double through the switch
• In three-way switch circuitry one switch is located at the top of the stairs and the other at one at the bottom. When the switch at the top stairs flipped to on state. It completed the circuitry and ON the light. When switching at the bottom of the stairs to on state. it breaks the circuitry at the top switch and completes for the circuit at the bottom switch and the light is oN
• The single pole double through a switch in this condition is the main component of both three-way switches and helpings circuit to be complete at any switch but not at both switches simultaneously.

FAQs

1. Write the maximum current rating of a DPST switch.

• The maximum current rating of the DPST switch depends on the size and construction of the switch. Normally DPST switches have the ability to handle current values from 10 to 30 amps.

2. Is the DPST switch control the flow of electricity in 2 circuits?

• Yes, it can control the current flow in two circuits like two separate switches

3. How to wire a DPST switch?

• For wiring, the Double pole single-through switch connects one input point with the power supply and another input terminal with the load. After that connect one output point to the power supply and the other output to the load

4. Write applications of DPST switches?

• These switches are sued in different electrical appliances like power supply to motors and machines on and off. It also has on and off lights and fans, controlling the heating element in a water heater

5. IsDPST switches be used as safety switches in heavy-duty machinery?

• Yes, it works as safety switches in heavy-duty machines since they are durable and have the ability to handle high current loads

Conclusion:

The double pole single throw switch is part of different devices and circuits where current flows. it has two poles that help the control current flow in two different circuits. The switch is durable and easy to maintain and install Wiring a DPST switch is a simple and easy process, but it must follow some safety precautions while working with it. Follow for more latest Electronics Information https://www.theengineeringknowledge.com/