摘要 |
Passive IR sensor detection circuitry is provided that consumes eighty to ninety percent less power than conventional PIR sensor detection circuitry. Whereas prior art PIR sensor detection circuitry employs multiple amplification stages, to boost the power of the weak sensor signal, and a window comparator to determine whether an occupancy condition exists, the present invention uses, at most, a single amplification stage and no window comparator. In place of multiple amplification stages and a window comparators, the PIR sensor circuitry of the present invention uses a sensitive microcontroller to both detect and process the signal. A peak detector can be added just before the signal-whether amplified or not-is received by the microcontroller. Decay time of the peak detector is adjusted so that the signal will not substantially decay between measurements.
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