Patent ID: 7551066

Claim:
A system for activating and/or deactivating a security device, in particular for access authorization systems and/or driving authorization systems of a motor vehicle, in which system an encoded information item is transmitted over air between a portable transmitter and a receiver, the receiver comparing the received information item with a predefined encoded information item, and outputting a drive signal to the security device when said two information items correspond, wherein the receiver ( 2 ) has a capacitive transmitter unit ( 10 , 11 ) comprising a first capacitor and generates a start signal ( 16 ) by means of an alternating electric field at the first capacitor, a receiver unit ( 13 ) of the transmitter ( 1 ) comprises a second capacitor for reception of the start signal, and transmission of the start signal from the first capacitor to the second capacitor is accomplished by a capacitive coupling between the first and the second capacitors.