Infrared IR Sensor Circuit Diagram and Working Working Principle Tarun Agarwal Electronics,, Sensors Electronics An infrared sensor is 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 . sually in the infrared spectrum, all the objects radiate some form of thermal radiations. These types types of radiations are invisible to our eyes, eyes, that can be detected by an infrared infrared sensor.The emitter is simply an IR !E" #!ight # !ight Emitting "iode$ "iode$ and the detector is simply an IR photodiode which is sensitive to IR light of the same wavelength as that emitted by the IR !E". %hen IR light falls on the photodiode, The resistances and these output voltages, change in proportion to the magnitude of the IR light received.
IR Sensor
IR Sensor Circuit Diagram Diag ram and Working Principle An infrared sensor circuit is one of the basic and popular sensor module in an electronic device. device. This sensor is analogous to human&s visionary senses, which can be used to detect obstacles and it is one of the common common applica applicatio tions ns in real real time.T time.This his circuit circuit compri comprises ses of the follow following ing components •
!'()* I+ I+ IR transmitter and receiver pair
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Resistors of the range of -ilo ohms.
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ariable resistors.
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!E" #!ight Emitting "iode$.
IR Sensor +ircuit In this project, the transmitter section includes an IR sensor, which transmits continuous IR rays to be received by an IR receiver module. An IR output terminal of the receiver varies depending upon its receiving of IR rays. Since this variation cannot be analy/ed as such, therefore this output can be fed to a comparator circuit. 0ere an operational amplifier #op1amp$ of !' ((2 is used as comparator circuit. %hen the IR receiver does not receive a signal, the potential at the inverting input goes higher than that non1inverting input of the comparator I+ #!'((2$. Thus the output of the comparator goes low, but the !E" does not glow. %hen the IR receiver module receives signal to the potential at the inverting input goes low. Thus the output of the comparator #!' ((2$ goes high and the !E" starts glowing. Resistor R3 #344 $, R #34- $ and R( #((4$ are used to ensure that minimum 34 mA current passes through the IR !E" "evices li-e 5hotodiode and normal !E"s respectively. Resistor R #preset6)- $ is used to adjust the output terminals. Resistor R3 #preset634- $ is used to set the sensitivity of the circuit "iagram. Read more about IR sensors.
Different Types of IR Sensors and Their Applications IR sensors are classified into different types depending on the applications. Some of the typical applications of different types of sensors are The speed sensor is used for synchroni/ing the speed of multiple motors. The temperature sensor is used for industrial temperature control. 5IR sensor is used for automatic door opening system and ltrasonic sensor are used for distance measurement.
IR Sensor Applications
IR sensors are used in various Sensor based projects and also in various electronic devices which measures the temperature that are discussed in the below. Radiation Thermometers
IR sensors are used in radiation thermometers to measure the temperature depend upon the temperature and the material of the object and these thermometers have some of the following features •
'easurement without direct contact with the object
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7aster response
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Easy pattern measurements
Flame Monitors
These types of devices are used for detecting the light emitted from the flames and to monitor how the flames are burning. The !ight emitted from flames e8tend from to IR region types. 5bS, 5bSe, Two1color detector, pyro electric detector are some of the commonly employed detector used in flame monitors. Moisture Analyers
'oisture analy/ers use wavelengths which are absorbed by the moisture in the IR region. 9bjects are irradiated with light having these wavelengths#3.3 :m, 3.; :m, 3.2 :m, and .<:m$ and also with reference wavelengths. The !ights reflected from the objects depend upon the moisture content and is detected by analy/er to measure moisture #ratio of reflected light at these wavelengths to the reflected light at reference wavelength$. In =aAs 5I> photodiodes, 5bs photoconductive detectors are employed in moisture analy/er circuits. !as Analyers
IR sensors are used in gas analy/ers which use absorption characteristics of gases in the IR region. Two types of methods are used to measure the density of gas such as dispersive and non dispersive.
=as Anali/er Dispersi"e# An Emitted light is spectroscopically divided and their absorption characteristics are used to analy/e the gas ingredients and the sample ?uantity. $on dispersi"e# It is most commonly used method and it uses absorption characteristics without dividing the emitted light. >on dispersive types use discrete optical band pass filters, similar to sunglasses that are used for eye protection to filter out unwanted radiation.
This type of configuration is commonly referred to as non dispersive infrared #>"IR$ technology. This type of analy/er is used for carbonated drin-s, whereas non dispersive analy/er is used in most of the commercial IR instruments, for an automobile e8haust gas fuel lea-ages. IR Imaging De"ices
IR image device is one of the major applications of IR waves, primarily by virtue of its property that is not visible. It is used for thermal imagers, night vision devices, etc.
IR Imaging "evices
7or e8amples %ater, roc-s, soil, vegetation, an atmosphere, and human tissue all features emit IR radiation. The Thermal infrared detectors measure these radiations in IR range and map the spatial temperature distributions of the object@area on an image. Thermal imagers usually composed of a Sb #indium antimonite$, =d 0g #mercury1doped germanium$, 0g +d Te #mercury1cadmium1telluride$ sensors. An electronic detector is cooled to low temperatures using li?uid helium or li?uid nitrogen&s. Then the +ooling the detectors ensures that the radiant energy #photons$ recorded by the detectors comes from the terrain and not from the ambient temperature of objects within the scanner itself an IR imaging electronic devices. Thus, this is all about IR sensor circuit with wor-ing and applications. These sensors are used in many sensor based electronics projects. %e believe that, you might have got a better understanding of this IR sensor and its wor-ing principle.7urthermore, any doubts regarding this article or projects please give your feedbac- by commenting in the comment section below.0ere is a ?uestion for you, can the infrared thermometer operate in complete dar-ness https://www.elprocus.com/infrared-ir-sensor-circuit-and-working/
Principles of Operation %e have already discussed how a light sensor wor-s. IR Sensors wor- by using a specific light sensor to detect a select light wavelength in the Infra1Red #IR$ spectrum. By using an !E" which produces light at the same wavelength as what the sensor is loo-ing for, you can loo- at the intensity of the received light. %hen an o bject is close to the sensor, the light from the !E" bounces off the object and into the light sensor. This results in a large jump in the intensity, which we already -now can be detected using a threshold.
Depiction of the operation of an IR Sensor
Detecting Brightness Since the sensor wor-s by loo-ing for reflected light, it is possible to have a sensor that can return the value of the reflected light. This type of sensor can then be used to measure how CbrightC the object is. This is useful for tas-s li-e line trac-ing.
Depiction of the operationof an IR Sensor to measure brightness
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