IR intruder detection device

摘要

The intruder detection device uses an IR transmitter (S) and an IR receiver (E) for the reflected IR radiation, which is compared with a reference signal, for signalling the presence of an intruder within the monitored space (R). The transmitted IR signal is modulated with a given modulation frequency (F1), the received IR signal modulated with a second modulation frequency (F2) and compared with a reference signal obtained by mixing the modulation frequencies.