- In 1950, Samuel Bango created the first motion sensor, which he called a burglar alarm. He used the fundamentals of radar to detect things that humans cannot hear, like fire or robbery, using ultrasonic vibrations. The “Doppler Effect” is the underlying theory behind the Samuel motion sensor. The majority of motion detectors on the market today operate on Samuel Bango’s detector theory. Sensors that use infrared and microwave technology to detect motion by altering the frequencies they output. You must first be familiar with camera operation to comprehend how a motion sensor functions. The lens of the camera focuses light onto an image sensor, and each pixel records how the light interacts with the sensor.
- Security systems used in workplaces, banks, and shopping centers, as well as residential burglar alarms, can use motion sensors. By identifying people nearby the sensor, current motion detectors can avert major mishaps. Motion sensors in public areas can be watched. The dual IR reflective sensor is the fundamental component of the motion detector circuit.
What is a Motion Sensor?
- A motion sensor is a device that notices moving objects, mainly people. A motion sensor is frequently incorporated as a component of a system that routinely performs a task or else alerts a user of motion in a region. These sensors form a very important component of security, home control, energy efficiency, automated lighting control, and other helpful systems. The main principle of the motion sensor is to sense a burglar and send an alert to your control panel, which gives an alert to your monitoring center. Motion sensors react to different situations like movement in your living room, doors, windows being unbolted or closed, and also these sensors can.
- Activate a doorbell when someone comes close to the front door.
- These sensors give you an alert whenever kids enter some restricted areas in the home such as the medicine cabinet, the basement, or the workout room.
- Conserve energy by using this sensor lighting in empty spaces.
Types of Motion Sensors
There various kinds of motion sensors are available in the market, which have their ups and downs. They are namely PIR, Ultrasonic, Microwave, Tomographic and combined types.
Passive Infrared (PIR) Sensor
- All warm-blooded animals produce IR radiation. Passive infrared sensors include a thin Pyroelectric film material, that responds to IR radiation by emitting electricity. This sensor will activate the burglar alarm whenever this influx of electricity takes place. These sensors are economical, don’t use more energy, and last forever. These sensors are commonly used in indoor alarms.
Ultrasonic Sensor
- Ultrasonic sensors can be active (or) passive, with the latter listening out for specific noises like glass breaking or metal hitting metal. Despite their high sensitivity, these sensors are typically pricy and prone to false alerts. The reflection of these waves off a moving object is determined by active ones, which produce ultrasonic wave (sound wave) pulses. Animals that can hear these sound waves, such as cats, dogs, and fish, may become alarmed if an active ultrasonic alarm is present.
Microwave Sensor
- These sensors generate microwave pulses and then calculate their reflection of objects, to know whether objects are moving or not. Microwave sensors are very sensitive, but sometimes these can be seen in nonmetallic objects which can be detected as moving objects outside of the target range. It consumes a lot of power, so these sensors are frequently designed to cycle ON & OFF. This makes it feasible to acquire past them if you know the cycles. Electronic guard dogs utilize microwave sensors.
Tomographic Sensor
- These sensors generate radio waves and detect when those waves are troubled. They can notice through walls and objects and are frequently placed in a way that makes a radio wave net that cover-ups large areas. These sensors are expensive, so they are normally used in warehouses, storage units, and also in other situations that need a commercial level of security.
Combined types of Motion Sensors
- Some types of motion detectors mix some sensors to decrease fake alarms. But, dual sensors are only activated when both kinds sense motion. For instance, a dual microwave or PIR sensor will start on the passive infrared sensor setting, because that consumes less energy. When the passive infrared sensor is tripped, the microwave division will turn ON; then, if the remaining sensor is also tripped, the alarm will generate sound. This combined type is great for neglecting fake alarms but tuns the possibility of missing real ones.
