Solenoid bolt Wikipedia
A solenoid bolt is a type of electronic-mechanical locking mechanism. This type of lock is characterized by the use of a solenoid to throw the bolt. Sophisticated solenoid bolt locks may use microprocessors to perform voltage regulation, reduce power consumption, and/or provide access control. Depending on the strength of the solenoid, some models can provide a holding force on the order of 1000 kg. A solenoid bolt can be designed either to fail open (the lock opens on power loss) or to fail closed (the device is locked upon power loss); cf fail safe. Some models may be suitable for high-security sites.