Magnetic Latches | Magnet-Schultz of America

Magnetic Latching Solenoids, often called Bi-Stable Solenoids, are operationally similar to conventional Solenoids in the respect that the solenoid armature (plunger) is “pulled-in” by passing electrical current through the solenoid coil.

The magnetic latching solenoid design also includes a permanent magnet, which serves to hold the armature in the latched position without the need to continuously apply power to the coil.

This power saving feature is the main advantage of the magnetic latching solenoid.

Applying a small reverse current to the solenoid coil allows the armature (magnetic latch/plunger) to return to the unlatched position. Typically, the return force is provided by a spring which is incorporated into the solenoid.

Typical applications for magnetic latching solenoids (open frame solenoids) are battery operated and other power critical scenarios such as Door Locking Mechanisms, Computer Cabinet Locks, and Electronic Circuit Breakers.

Magnetic Latch Mechanisms

Magnetic Latches are bi-stable linear actuators which utilize the energy stored in a compressed spring. The four key components within Electromagnetic latches are an armature (plunger), an internal spring, a permanent magnet and a small electrical coil.

The armature of the a magnetic latch mechanism must be manually pushed in, against the opposing internal spring force, to a point where the permanent magnet can attract and hold the armature into what is called the “latched” position.

Activation of the magnetic latch mechanism is accomplished by applying a small pulse of electrical current to the coil. The resulting magnetic field disrupts the holding force of the permanent magnet, thereby allowing the internal spring to thrust the armature into the unlatched position.

The main advantages of the magnetic latch mechanism are:

Significantly higher actuation and impact forces than a solenoid of the same size.
Actuation can be accomplished with a very small pulse of current.

Typical applications include Fire Extinguishing Systems and Power Line Interrupter Trip Mechanisms.

Benefits of Magnetic Latches

Looking to decrease the operating cost and the thermal output of solenoids in low duty cycles? Choose a magnet latching option from Magnet-Schultz of America. Magnetic latching solenoids, also referred to as bi-stable or open frame solenoids, utilize a permanent magnet to hold the armature in a latched position, eliminating the need to apply continuous power to the coil. This design offers a number of advantages:

Reduced power consumption—the actuator can stay in position (either in or out) indefinitely without the constant input power a regular solenoid requires
Lower heat—since the solenoid is actuated with a brief burst of power, virtually no heat is generated
Battery friendly—the minimal power requirements of magnetic latches make them ideal for use with the small output of a battery power source
Greater force—because the return force of the armature is provided by a built-in spring rather than the solenoid itself, magnetic latching solenoids provide higher actuation and impact forces than an unequipped solenoid of the same rating

Typical applications for magnetic latching solenoids (open frame solenoids) include Door Locking Mechanisms, Computer Cabinet Locks and Electronic Circuit Breakers.

To explore the design possibilities of magnetic latching solenoids, contact us for a consultation with a Magnet-Schultz application expert.

Benefits of Magnetic Latches

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