A sensor is used to identify changes in events or quantities and produce the appropriate output signals, such as an optical or electrical signal. Although there are many different kinds of sensors, two main categories exist: analog sensors and digital sensors. The different kinds of sensors include those that measure pressure, temperature, gas, fire, pyroelectric, piezoelectric, infrared, and PIR, among others. This article focuses specifically on the operation of the PIR sensor circuit module.
PIR Sensors(What is a PIR sensor?)
Passive infrared (PIR) sensors are electronic sensors that are used to detect human or any physical movement within a specific range. They have an average value of around 10 meters, but their real detection range is between 5 and 12 meters. PIR sensors function as pyroelectric sensors that measure infrared radiation levels. There are various kinds of sensors; here we'll talk about PIR sensors that have dome-shaped Fresnel lenses.
For many electronics applications, the PIR sensor circuit is utilized to detect whenever any person enters or exits a certain space. These passive infrared sensors have a broad range of lens options, have flat control, and are simple to integrate with electronic circuits.
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| Fig: Pin Configuration |
The figure displays the PIR sensor's pin layout. Three pins make up a PIR sensor: power, signal, and ground at the bottom or side. PIR sensors typically have a 5V maximum power output; however, large-sized PIR modules use a relay instead of a direct output. Connecting a sensor to a microcontroller is a pretty straightforward process. The PIR's output can be either high or low, and it is often digital.
PIR Sensor circuit
The power supply pin, the output signal pin, and the ground pin make up the three pins that make up the PIR sensor circuit. In addition to the filter window and ceramic substrate depicted in the picture, the PIR sensor circuit also features a dome-shaped component known as a Fresnel lens.
PIR Sensor Working Principle(How pir sensor work?)
PIR sensors pick up infrared radiation from moving hot bodies whenever a human, or even a warm body or anything with some warmth, passes through their range of vision. Thus, the sensor's detection of infrared radiation produces an electrical signal that can be utilized to turn on an alarm, buzzer, or alert system.
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| Photo Courtesy: gl-e.uk |
PIR Sensor Applications
PIR sensors are widely used in many different fields, including covered parking areas, automatic door operating systems in shopping malls, automatic lighting control of outdoor lights, lift lobbies, common staircases, and garden lights based on human presence.
PIR Motion sensor wiring diagram
Most PIR modules have a three-pin connection on the side or bottom. One pin will be ground, another will be signal, and the last will be power. Power is typically 3-5VDC input, but can be as high as 12V. Larger modules do not always have direct output and rather operate a relay, in which case there are ground, power, and two switch connections.
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| Motion sensor light/alarm circuit |
