Thursday, April 4, 2013
Infrared Motion Detector Circuit Using LM11458
This is a design circuit 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 circuit uses this principle to sense the motion. This circuit is work based on LM11458 IC as the controller of the circuit. This is the figure of the circuit.
The operation of the circuit is the following. The IC1 (NE 555) is wires as an astable multi vibrator .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, 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. Comparators IC2a and IC2b are belonging to the same IC2 (LM11458). So the power supply is shown connected only once. When there is disturbance in the air or vehicles passing nearby, the circuit may get false triggered. POT R5 can be used for sensitivity adjustment.
The operation of the circuit is the following. The IC1 (NE 555) is wires as an astable multi vibrator .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, 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. Comparators IC2a and IC2b are belonging to the same IC2 (LM11458). So the power supply is shown connected only once. When there is disturbance in the air or vehicles passing nearby, the circuit may get false triggered. POT R5 can be used for sensitivity adjustment.
