LOW POWER OPERATING METHOD OF WIRELESS PASSIVE INFRARED DETECTOR TO PROLONG LIFETIME OF BATTERY AND LOW POWER OPERATING SYSTEM THEREOF

摘要

Provided is a low power operating method for prolonging lifetime of a battery in a wireless passive infrared (PIR) sensor and a low power operating system using the same. The low power operating system for prolonging lifetime of a battery in a wireless PIR sensor comprises: a PIR element sensing an object, an amplifier amplifying an electrical output signal from the PIR element, a window comparator receiving the output signal from the amplifier, and outputting a square wave when the received output signal has a predetermined voltage or higher, an A/D converter receiving the amplifier output signal and being controlled by an MCU, a temperature sensor sensing and outputting a temperature of ambient air, a second A/D converter receiving an output from the temperature sensor and being controlled by the MCU, and the MCU receiving an output from the window comparator, recognizing the received output as a reliable input in a case where the output is received as having a voltage equal to or higher than a preset voltage of 50 ms by considering ambient temperature, RF noise, and the like, and controlling the A/D converter to operate to determine whether a person has trespassed, and controlling the second A/D converter to operate to receive an output from the temperature sensor at every wake-up time repeated for every 30 minutes or one hours to change the preset voltage according to a change in an ambient temperature to compensate for a temperature.