Anti-theft or cable connection detector for electric equipment plug on mains supply e.g computer

摘要

The protective cable (2) has a special female plug (3) supplying the equipment (1) being protected. The earth terminal of the plug is divided into two independent metal strips isolated from each other. One is connected to the earth of the supply and the other is connected to an impedance loop and to a microprocessor placed in the plug. The strips are connected by the male pin (8) of the equipment. When the plug is disconnected, the microprocessor (4) alerts a local unit (6) using ASCII code. The local unit receives and authenticates the message and gives an appropriate alarm. The local unit regularly requests identification signals from the microprocessor and gives an alert when no reply is received. The system may be expanded to give physical measurements and other data.