What is a Solenoid Switch : Working & Its Applications

Solenoid switch is used in high power circuits for switching purposes by using a small electrical control signal. This switch mainly uses decision making as well as extensive logic circuits to perform on economical microchips & tiny electronic parts. It also allows high power switching apparatus to be restricted to a remote area. These switches are normally used in automobiles to start the engine systems. This article discusses an overview of what is a solenoid switch and its working.

What is a Solenoid Switch?

Definition: An electrical switch that is frequently used where a high current circuit namely a starter motor circuit is brought into action with the help of a low current switch is called a solenoid switch. This switch turns ON a durable switch to connect the battery of a vehicle to the motor’s starter. Once the ignition key is activated then a solenoid switch connects the drive pinion of starter. The main features of solenoid switches are high performance, reliability, and durability.

Solenoid Switch
Solenoid Switch

Working Principle

Solenoid switches are wire wound magnetic coils including an open core to get a cylindrical plunger with sliding. Once the coil is activated then, a magnetic field can occur within the hollow opening which drags the cylindrical plunger into it depending on the direction of the switch as well as the plunger’s poles. Here the connection of plunger can be done to a set of switch contacts by mechanically to execute the high-power switching.

On a solenoid switch, there are four connector terminals are there where the coil uses two and can be most frequently isolated from all the remaining terminals. So that it keeps the coil totally independent. Generally, the terminals of the switched current are significantly heavier compare with the terminals of the coil.

Solenoid Switch Types

Most of these switches include only one switched pole because of the current flow through them. Some switches operate only for a moment like starter solenoids used in automobiles. When the engine of an automobile is activated, then both the motor’s starter, as well as a switch, is totally isolated from the electrical system. Some of the automotive systems include the moving plunger for sliding the starter pinion with the starter shaft. So that it connects the flywheel and also gives power to the starter motor.

How to Wire a Solenoid Switch

These switches mainly used for controlling the circuit with a large current by using a switch with low current.


These devices have a switch with high current, controlled through a magnetic actuator known as a solenoid. Once small current supplies through the solenoid, then the core of this will move to force switch which has high current to the closed location. Based on the solenoid size, it includes four terminals. From that, two terminals are used for low current circuits whereas the remaining terminals are used for the high current circuit of the solenoid. To connect a solenoid switch, there are different steps involves like the following.

  • Connect the terminals of high current switch to the solenoid switch, and then observe the documentation supplied using the switch for the position of two terminals.
  • Slash two pieces of black wire and connect one finish of the initial black wire to the -ve terminal of the battery. Similarly, connect the second end of the wire to one of the high-current terminal of the switch.
  • Connect the other black wire to another high-current terminal of the switch. After that, attach the next end of that similar wire to the DC motors -ve terminal.
  • Slash one part of red wire and connect one finish to the +ve terminal of the motor & attach the other finish to the +ve terminal of the battery. So that a high current circuit can be formed.
  • Slash two parts of black wire & attach one finish of the primary wire to the initial low current terminal over the switch. Attach the remaining finish to one of the terminals of the 6V switch and the remaining terminal can be connected to the –Ve terminal of the 6V battery.
  • Arrange one red color wire among the +ve terminal of the battery & fix the remaining finish to the next low-current terminal over the switch. So that a low current circuit can be formed.
  • At last, switch ON the 6V switch then DC motor will start running.

Solenoid Switch in Automobile

The role of solenoid switch in automobiles includes the following.

  • Solenoids carry a current that, when energized, creates a magnetic field. This magnetic field produces a high force and current source of power for activating devices used in electrical applications and vehicles, such as automotive and industrial
  • The solenoid switch triggers a durable switch that unites the battery of the vehicle to the starter motor.
  • Once the ignition key is in the initial position, then this switch connects the drive pinion of the starter.


The solenoid switch applications mainly include the following.

  • Solenoid switch is used to control high power circuits with the help of small electrical control signals for activating the switch.
  • It also allows a high power switching device to be restricted to a remote place.
  • These switches are normally used on engine starting systems within the automotive.

Thus, this is all about an overview of the solenoid switch. These switches are made-up with the help of the best rating and huge quality raw materials. The applications of these switches mainly involve in automobiles as well as industrial purposes. Here is a question for you, what are the technical specifications of solenoid switches?

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