June 16, 2022
PIR sensors
Often just called motion sensors, these are widely available and interesting.
PIR is Pyroelectric Infrared Sensor. The "P" may also be translated "passive".
This is in contrast to an active sensor that emits an IR beam from an LED or laser.
A PIR has two IR sensors that sense the IR being received from two zones in front
of the sensor. Changes in the two zones (differences between the two?) trigger
the sensor.
Have any comments? Questions?
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Tom's Electronics pages / tom@mmto.org