Detection device for stolen motor vehicles in cross-border traffic - utilises transmitter in vehicle, sending out digital signal with alphanumeric code, and receiver at border post

摘要

A security device for vehicles, especially for motor vehicles in cross-border traffic, incorporates a transmitter built into the vehicle, sending out a digital signal comprising an alphanumeric code. There is a receiver at the border post which detects, decodes and evaluates this signal. The transmitter comprises separate elements to store the sequence of digits or letters, to encode them using programmable ROM and to transmit them. A second different coded signal can be transmitted after a preset time interval from the first signal. The transmission frequency is 423.93 (433.93) MHz and the power is 20 mW, giving a range of 20 metres. ADVANTAGE- Stolen vehicles easily detected at border posts.