Home Industry Working Of Solenoid Switch and Its Applications

Working Of Solenoid Switch and Its Applications

by Wilbur

A solenoid switch is present in a setting where a low current switch regulates the power supplied to a high current circuit. The primary function of the solenoid switch is to connect the starter motor to the battery. Although, solenoid switches are present in different circuits. But their most common application is in the car starting systems.

Below the article dives deep into the mechanics of the solenoid switches.

A Quick Overview of Working Mechanism

Initially, cars used manual switches. But, now, they include electrical switches called the solenoid switches. The coil used to make a solenoid switch is called a solenoid, hence the name. When the key turns, the current flows from the battery to the coil, which moves the plunger.

The motion of the plunger connects the contact disk to the starter motor. The process powers the engine. Once the engine activates, the switch and the engine starter disconnect. Solenoid switches vary in their designs and orientations but deploy similar working mechanisms.

How to Wire a Solenoid Switch?

Solenoid switches use coils to control the amount of the supplied current. The size of the switch depends on the coil used. Usually, there are four terminals—two terminals for low current and the other two for high current. To connect the solenoid switch, you can follow the following steps.

Making the High Current Circuit

Take a black wire and strip it to about half an inch on both sides. Connect one end of this wire to the -ve terminal of the battery and the other one to a high current terminal of the solenoid switch.

With one more black wire, connect the other high current terminal of the solenoid switch to the -ve terminal of the battery. Now take a red wire and strip its ends. Connect the positive terminal of the battery to the motor’s positive terminal. The process establishes the high current circuit.

Making the Low Current Circuit

Now take a piece of black wire and connect its one end to the low current end of the solenoid switch. Connect the other end of the same wire to any one terminal of the starter switch. Now connect the other free terminal of the switch to the battery’s negative terminal. Lastly, connect the positive terminal of the battery and the second low end of the solenoid switch using a red wire.

Testing the Connections

Secure all the connections and test the motor by turning the key. It should power up the system and rotate the engine.

Application of a Solenoid Switch

Solenoid switches are used for low-current applications. The devices are also known as latching solenoids. They can hold their position without the need for continuous power supply. The mechanism uses an electromagnet to move a ferrous metal. It can be either an iron core or plunger within a coil.


Solenoid switches are rapidly becoming popular due to their efficient performance. However, connecting it right is necessary; else it may damage the car battery. Therefore, the article explains the wiring process of the solenoid.

The solenoid also has several industrial applications like remote controlling a high-current circuit. But commonly, it’s there in your car as you turn on the key.

You may also like

Leave a Comment