Supercapacitors in Locks

Many locks use solenoids which have hard wired power or use batteries. A supercapacitor in the lock enables the energy source to only supply average power allowing the use of thinner wiring or lower power batteries. Further, in the event of power fail, the lock must be set to the safe state, either open or locked. This is set by a spring fitted in the factory. The energy stored in the supercapacitor can replace the spring, enabling the lock safe state to be programmed on site.

Supercapacitors deliver peak power for lock activation…

Electronic lock mechanisms rely on an electromechanical actuator in the form of a solenoid or geared motor to perform the lock and unlock actions. They can either have wired power, such as in an access control system, or have battery power such as hotel room locks. The lock can draw a significant peak current, particularly starting current during the initial activation. A supercapacitor can supply this peak current allowing the energy source to supply only average power which allows for thinner wiring or smaller, lower power batteries that are a better fit in the confined space of door lock.

… and backup power to set the lock in a safe state.

By default, most e-locks will enter either a locked or unlocked state during a power failure, whichever is the safe state. This is often set by a spring which is fitted at the factory. Instead of mechanical energy in a spring, the electrical energy stored in a supercapacitor can set the lock in the safe state in the event of power fail. This can now be programmed on site.

For more details see Application Brief Supercapacitors in Locks.