Wiring & diagram Info: infrared

Monday, October 13, 2014

Infrared Light Photo Detector Circuit This is a basic infrared light photo detector circuit In this circuit the light falling on the phototransistor

Infrared Light Photo-Detector Circuit

This is a basic infrared light photo detector circuit. In this circuit the light falling on the phototransistor will be from an Infrared Light Emitting Diode (IrLED) but otherwise it is the same as the phototransistor circuit shown above.

When the light falling on the phototransistor (Q1) is blocked, its conductance will decrease and the voltage across Q1 will rise. When the voltage rises above 1/2 of the supply voltage the output of the comparator will turn ON and the LED will be lit.

Source: Infrared Light Photo-Detector

Infrared motion detector circuit

Here is the schema diagram of an infrared motion detector that can be used to sense intrusions.Infra red rays reflected from a static object will be in one phase, and the rays reflected from a moving object will be in another phase.The schema uses this principle to sense the motion.

The IC1 (NE 555) is wired as an astable multivibrator .The IR diode connected at the output of this IC produces infrared beams of frequency 5Khz.These beams are picked by the photo transistor Q1 .At normal condition ie; when there is no intrusion the output pin (7) of IC2 will be low.When there is an intrusion the phase of the reflected waveforms has a difference in phase and this phase difference will be picked by the IC2.Now the pin 7 of the IC 2 goes high to indicate the intrusion.An LED or a buzzer can be connected at the output of the IC to indicate the intrusion.

Notes.

* Comparators IC2a and IC2b are belonging to the same IC2 (LM1458).So the power supply is shown connected only once.No problem.
* When there is disturbance in the air or vehicles passing nearby,the schema may get false triggered.
* POT R5 can be used for sensitivity adjustment.

Monday, October 13, 2014

Infrared Light Photo Detector Circuit This is a basic infrared light photo detector circuit In this circuit the light falling on the phototransistor

Infrared Light Photo-Detector Circuit

Thursday, August 28, 2014

Infrared motion detector circuit