Infrared motion detectors work by sensing heat in the area they are scanning. All living things give off infrared energy as a part of their body heat. Internal sensors in the motion detector notice the change and set off a light or alarm. Beyond the sensor itself, the elements involved are very simple: just a power source, a central control unit, and an alarm. You can make a motion detector of your own with the right tools and a few electronic components.
Instructions
1. Connect the positive (+) wire from a 9v battery clip to the positive (+) terminal of a PolyBlock, and the negative (-) wire from the battery to the 0v terminal of the PolyBlock.
2. Connect the red wire from a PIR sensor to the 5v terminal on the PolyBlock. Then connect the black wire to the 0v terminal on the PolyBlock and the yellow wire to input 2 on the PolyBlock.
3. Set the function switch on the PolyBlock to 0010. That will keep the alarm on after the intruder leaves the range of the sensor.
4. Connect the positive (+) lead from a buzzer or alarm to the +V connector on the PolyBlock, and the negative (-) lead from the buzzer or alarm to the S0 connector on the PolyBlock.
5. Connect the battery to the clip. This will power the motion detector.
6. Adjust the onboard trimpot of the PolyBlock to determine how long the buzzer will sound once motion is detected. You can calibrate it to any amount between a second or two and fifteen minutes. For the shortest amount of time, set the trimpot counterclockwise. Gradually turn it clockwise to lengthen the duration.
Tags: terminal PolyBlock, motion detector, wire from, alarm connector, alarm connector PolyBlock, battery clip, buzzer alarm