How-to make IRsensorproject | ir sensor detailed working | touchless door bell Module at home| Diy IRproximity sensor

An infrared sensor is an electronic device, that emits in order to sense some aspects of the surroundings. An IR sensor can measure the heat of an object as well as detects the motion.These types of sensors measures only infrared radiation, rather than emitting it that is called as a passive IR sensor.

How-to make IRsensorproject | ir sensor detailed working | touchless door bell Module at home| Diy IRproximity sensor

We know that the first application in electronics starts with sensors. The basic one is IR sensor and it is a very popular sensor, which is used in any kind of obstacle or object detection with different logic like sensing hand or person etc.

This sensor includes IR transmitter LED and IR sensing LED . This sensor can be made by different ways but we are going to make it using LM358 comparator IC. This IC has two Operational Amplifier ports. We are going to use one side as we need single side sensing task. In each port of this IC three pins are available which are non - inverting terminal PIN 2, inverting terminal PIN 3 and an output PIN 1. When voltage at non- inverting terminal is higher than inverting terminal the output gets high which means it will provide a voltage output as signal.

robotshapers lm358

fig.1.1 - LM358 ic

Circuit diagram:

fig .1.2 Ir proximity sensor circuit diagram

fig .1.3 Ir proximity sensor Breadboard diagram

Component required:

LM358NIC
IR Transmitter LED
IR Receiver LED
RESISTORS R1= 1K

R2 = 100 E

R3 =10K

Variable resistor Vr1 = 10k

LED
9v batterywith cap

Working:

In above circuit we have connected pin 3 with photo diode which is non inverting terminal when IR rays will hit sensor LED the ressistivity through it pins will be lowered and voltage supply will get high on the pin 3 which results as high output at PIN1 . In our requirement we want to make a variable sensing device so that we can manipulate the sensivity or set the value of intensity to be sensed . we add a variable resistor at pin 2. As the variable resistor is set for low resistance, the voltage on pin 2 gets high. The non- inverting terminal PIN 3 requires higher input signal to overcome the voltage on PIN 2 for higher output which means it is set for high intensity of IR light. As the resistance is improved the the sensivity of the sensor increases due to lesser voltage requirement in PIN3.