A solenoid is an electric coil with a movable ferromagnetic core (plunger) in its center. The solenoid converts electric current to linear motion.


Solenoid valve

This solenoid valve consists of the Kohsel solenoid and the valve body (G).

The figure below shows the different components in the solenoid valve.

A solenoid has an electromagnetically inductive coil (A) around an iron core at the center called the plunger (E). At rest, the plunger can be normally open (NO) or normally closed (NC).

In the de-energized state, a normally open valve is open, and a normally closed valve is closed.

When current flows through the solenoid, the coil is energised and creates a magnetic field. This creates a magnetic attraction with the plunger, moving it and overcoming the spring (D) force.

If the valve is normally closed, the plunger is lifted so that the seal (F) opens the orifice and allows flow through the valve. If the valve is normally open, the plunger moves downward so that the seal (F) blocks the orifice and stops flow through the valve.

The shading ring (C) prevents vibration and humming in AC coils.

Kohsel solenoids are used for clean liquids and gases.

Gas stove

Solenoid coil for valve used to control the flow of gas in a stove.

Refrigerated counter

Solenoid coil for valve used to control the flow of liquid in a refrigerator


Solenoid coil for electrohydraulic valve, used to control the flow of hydraulic fluid in an excavator

Solenoid tripping coils (trip coils) inside circuit breakers

The trip coil is the release component in a circuit breaker (used in energy distribution for the switching of high currents). The circuit breaker must interrupt fault currents/voltages to protect downstream systems. A trip coil initiates this separation mechanism.

Kohsel trip coils are specially designed linear solenoids which meet the requirements of the field of energy distribution. We design the optimum trip coil for the application based on energy availability, power requirement, installation space, and environmental requirements.

Our solenoids are packed on antistatic plastic arrays that are well-suited to use on an efficient production line.


Encapsulation gives your coil maximum structural integrity and impact resistance in all environments. Kohsel has many years’ experience with encapsulation of solenoid coils on a large scale.

Every day, we strive to unleash the full potential in inductive design. Through our proven process, dedicated engineering and close collaboration, we detect untapped savings and optimization potential throughout your entire value chain.