Electromagnetic Lock (Mag Lock)

TL;DR: An electromagnetic lock (mag lock) is a locking device that uses an electric current to generate a magnetic force, securing a door until power is removed or interrupted. It is widely used in access control systems for high-security applications.

What is an Electromagnetic Lock (Mag Lock)?

An electromagnetic lock, or mag lock, is a locking mechanism that secures a door using an electromagnet and an armature plate. When powered, the electromagnet creates a strong magnetic force that holds the door closed. To unlock, power is cut off, releasing the door instantly.

Mag locks are commonly used in offices, government buildings, and high-security facilities due to their durability, reliability, and integration with access control systems.

How Does an Electromagnetic Lock Work?

1. Electromagnet Activation – When power is supplied, the electromagnet generates a strong magnetic field.
2. Door Securing – The magnet holds the armature plate (attached to the door), keeping it locked.
3. Access Control Input – A keycard, keypad, biometric scanner, or remote signal triggers the system.
4. Power Cut to Unlock – When access is granted, power is interrupted, releasing the magnetic force and unlocking the door.
5. Automatic Relocking – When the door closes and power is restored, the magnet re-engages.

For example, in an office with a keycard entry system, swiping a card triggers the access control unit, which temporarily cuts power to the mag lock, allowing the door to open.

Types of Electromagnetic Locks

1. Fail-Safe (Power-to-Lock) – Requires continuous power to stay locked; when power is lost (e.g., during an emergency), the door unlocks automatically.
2. Single-Door Mag Lock – Used for standard doors with a single locking point.
3. Double-Door Mag Lock – Designed for double doors with two electromagnets for secure locking.
4. Shear Locks – A hybrid mag lock that provides both magnetic and mechanical locking for increased security.

How to Implement a Mag Lock in an Access Control System

1. Choose the Right Mag Lock – Determine the required holding force (measured in pounds) and whether fail-safe operation is needed.
2. Mount the Lock & Armature Plate – Secure the electromagnet to the door frame and the armature plate to the door.
3. Connect to the Access Control System – Wire the lock to a power supply and integrate it with keycard readers, keypads, or biometric systems.
4. Set Up Emergency Release Mechanisms – Install exit buttons, motion sensors, or fire alarm integrations to ensure safe egress.
5. Test & Maintain – Regularly inspect and test the lock to ensure proper functionality and security.

Conclusion

Electromagnetic locks provide a strong, reliable, and secure locking mechanism for access control systems. They are ideal for applications requiring remote operation, high holding force, and fail-safe security, ensuring both safety and convenience in controlled environments.