ELECTRONIC VARIABLE COMBINATION LOCK AND MONITORING SYSTEM

A variable combination electronic lock is provided in which the combination may be varied electronically. The lock is provided with means for receiving a key having a combination. The combination of the key is detected and the detected combination is checked or compared with the combination assigned to the lock. If the combination on the inserted key is identical to the assigned combination, a lock release means of the lock is enabled. In one preferred use, a plurality of locks is provided with each lock being assigned an address. All of the locks may be connected to an electronic processor by means of a single system cable. The electronic processor stores a combination for each of the locks. Each of the plurality of locks is addressed in sequence, and the combination of the key, if any, inserted into the key receiving means of the lock is transmitted to the electronic processor for comparison with the combination stored. In addition, other information indicative of predetermined conditions at the location of each lock, such as the existence of excessive heat due to a fire, may be transmitted to the electronic processor. If the combination transmitted to the electronic processor from a particular location agrees with the stored combination, a lock enable signal is transmitted over the system cable with the address of the particular lock thereby enabling or opening that lock.