This design uses BISS0001 to comple

This design uses BISS0001 to complete the processing of the output signal of the pyroelectric infrared sensor. Because the output signal of the pyroelectric sensor changes slowly and has a small amplitude, it cannot be directly used as the control signal of the light bulb. Therefore, the output signal of the sensor must pass through a special signal. The processing circuit converts the irregular waveform of the sensor output signal into a digital signal suitable for single-chip processing.In Figure 4, the output signal of the pyroelectric sensor is sent to pin 14 of BISS0001. After passing through the internal first-stage operational amplifier, it is coupled by C3 and input from pin 12 to the internal second-stage operational amplifier for amplification, and then is formed by a voltage comparator. After processing by the amplitude discriminator, the output signal (V0) from pin 12 is finally sent to the single-chip microcomputer for lighting control. Pin 1 of BISS0001 is connected to a high level, so that the chip can be triggered repeatedly. The delay time T1 of output V0 is adjusted by the size of external R8 and C7; the trigger blocking time T2 is adjusted by the size of R9 and C6.