The security system comprises an electric motor drive for the lock and a solenoid for the locking bolt. The motor (2) and solenoid (3) are mounted near to the driving circuits (11) via short leads. The controller (6) is linked to the system by leads with a large capacitor (18) across the input of the motor housing. This provides sufficient charge to prevent voltage drop during switch on of the servo motor of the solenoid.The supply leads are loaded with low ohmic resistances. The system can be improved by using a microprocessor in the lock housing and connecting same to the processor control via a control bus. Special resistances in the supply lines are used to monitor the currents drawn by the servo motor and the solenoid to identify non standard conditions i.e unauthorised use of the locks.
