Unidirectional motion sensor

Posted on Jun 11, 2012

This circuit detects an object passing in one direction but ignores it going the opposite way. Two sensors define the sense of direction. The object blocks the light to phototransistor Ql or Q2 first dependent on the direction of approach. When the object passes Ql then Q2, an output pulse is generated at D; while no pulse is seen at D as the object passes Q2 then Ql.

Unidirectional motion sensor
Click here to download the full size of the above Circuit.

Object length (measured along the direction of the two sensors) should be greater than the separation of the two sensors Ql and Q2.

Leave Comment

characters left:

New Circuits



Popular Circuits

Negative Voltage Generator Schematic
60 watt 2n3055 power amplifier
Mesa Mark IIc+ Preamplifier
Simple Square Wave Generator Circuits
Random Flasher for 8 LEDs Project
LED Circuit with Timer 555
Microchips MCP73113 Li-Ion Battery Charger
Harnessing the sun with solar garden light
Cheap 12V to 220V Inverter
Compressor For Electret Microphone