Small HF transmitter unit serving as antitheft device for articles - has integrated circuit chip with programmed memory contg. data which can be sent as serial answer signals when min. voltage level is reached

摘要

A h.f. transmitting unit (10), of the type used within a label used to protect against theft, is in the form of a microchip. The chip has an EEPROM (11) for data, a parallel to serial converter (13), an output word generator (14) and a h.f. transmitter stage (15) coupled to an antenna (16). A voltage generator (17) is connected to a voltage watchdog circuit (18) that activates a control and clock generator (19) when a min. voltage is exceeded. This causes an address stage (20) to access the memory for data to be transmitted. Each chip may have the memory programmed with specific data from an external source via an interface. ADVANTAGE - Allows individual identification data to be stored and transmitted for object identification.