Abstract: An identification system in which power drain is minimized is disclosed. The system comprises a reader (10) including a first signal generator (12) for generating a first signal (F1) which is then radiated by an antenna (17). An identifier (11) is shown which includes an antenna (20) for receiving the first signal for transmission to a signal modulator (32) which operates to modulate the first signal in accordance with a preassigned code for the identifier. The modulated signal is then used to periodically unload or change the reactance of the antenna (20) which action in turn changes the reactance of the reader antenna (17) and the consequent voltage on the reader antenna. By detecting the change in the voltage on the reader antenna the code of the identifier is determined. Power is used efficiently by low frequency oscillation within the signal modulator, by unloading during modulation, and by changing circuit reactance without changing the circuit load.

Abstract: An electronic security system and an electronic proximity key for use therein are disclosed in which a multitiered distributed architecture is used to rapidly and flexibly provide ingress and egress through a plurality of electronic locks. In the event of loss of communication with the central processor, the system will continue to function at lower levels of security without interrupting requests for ingress and egress, and will continue to provide alarm monitor processing. An improved proximity key for actuating the security system is disclosed which includes coupling coils that are integrally formed as part of the integrated circuit lead frame associated with the coding circuitry of such key.