ELECTRONIC SECURITY DEVICE

摘要

An electonic security device includes a memory and a card reader which reads a combination code and calculation data from a key card. An electronic circuit compares the content of the memory with the combination code and enables the lock device if a match is found. If the key card is a new one the circuit calculates a new combination code by applying the calculation data to the memory content and, if this new combination code matches that on the key card the memory is loaded with the new combination code.