An IR LED, also known as IR transmitter, is a special purpose LED that transmits infrared rays(not visible to the naked eye) in the range of 760 nm wavelength. An infrared LED operates like a regular LED, but may use different materials to produce infrared light. Such LEDs are usually made of gallium arsenide or aluminium gallium arsenide. They, along with IR receivers, are commonly used as sensors.
Appearance
The appearance is same as a common LED. Since the human eye cannot see the infrared radiations, it is not possible for a person to identify whether the IR LED is working or not, unlike a common LED. To overcome this problem, the camera on a cellphone can be used. The camera can show us the IR rays being emanated from the IR LED in a circuit.
An infrared LED is, like all LEDs, a type of diode, or simple semiconductor. Diodes are designed so that electric current can only flow in one direction. As the current flows, electrons fall from one part of the diode into holes on another part. In order to fall into these holes, the electrons must shed energy in the form of photons, which produce light.
The wavelength and color of the light produced depend on the material used in the diode. Infrared LEDs use material that produces light in the infrared part of the spectrum, that is, just below what the human eye can see. Different infrared LEDs may produce infrared light of differing wavelengths, just like different LEDs produce light of different colors.
2.Infrared light can also be used to transfer data between electronic devices. Mobile phones, personal digital assistants (PDAs), and some laptops may have an infrared LED and receiver designed for short-range data transfer.
3.Although invisible to human eyes, many types of cameras and other sensors can see infrared light. This makes infrared LED technology well-suited to applications like security systems and night vision goggles. Many security cameras and camcorders use infrared LEDs to provide a night-vision mode. Hunters may use similar equipment to spot game at night, and some companies sell flashlights with an infrared LED to provide extra illumination for night-vision cameras or devices.
4.Robots may use an infrared LED to detect objects, and some utility meters even have an infrared LED to transmit data to a tool for easy meter reading.
Object Detection using IR light
It is the same principle in ALL Infra-Red proximity sensors. The basic idea is to send infra red light through IR-LEDs, which is then reflected by any object in front of the sensor.
For detecting the reflected IR light, we are going to use a very original technique: we are going to use another IR-LED, to detect the IR light that was emitted from another led of the exact same type.
This is an electrical property of Light Emitting Diodes (LEDs) which is the fact that a led Produce a voltage difference across its leads when it is subjected to light. As if it was a photo-cell, but with much lower output current. In other words, the voltage generated by the leds can't be - in any way - used to generate electrical power from light, It can barely be detected. that's why as you will notice in the schematic, we can use a Op-Amp (operational Amplifier) to accurately detect very small voltage changes.
Appearance
The appearance is same as a common LED. Since the human eye cannot see the infrared radiations, it is not possible for a person to identify whether the IR LED is working or not, unlike a common LED. To overcome this problem, the camera on a cellphone can be used. The camera can show us the IR rays being emanated from the IR LED in a circuit.
Concept of IR Sensor:
Interfacing:An infrared LED is, like all LEDs, a type of diode, or simple semiconductor. Diodes are designed so that electric current can only flow in one direction. As the current flows, electrons fall from one part of the diode into holes on another part. In order to fall into these holes, the electrons must shed energy in the form of photons, which produce light.
The wavelength and color of the light produced depend on the material used in the diode. Infrared LEDs use material that produces light in the infrared part of the spectrum, that is, just below what the human eye can see. Different infrared LEDs may produce infrared light of differing wavelengths, just like different LEDs produce light of different colors.
Application:
1.One or more LEDs inside the remote transmit rapid pulses of infrared light to a receiver on the television. The receiver then decodes and interprets these pulses as a command and carries out the desired operation.2.Infrared light can also be used to transfer data between electronic devices. Mobile phones, personal digital assistants (PDAs), and some laptops may have an infrared LED and receiver designed for short-range data transfer.
3.Although invisible to human eyes, many types of cameras and other sensors can see infrared light. This makes infrared LED technology well-suited to applications like security systems and night vision goggles. Many security cameras and camcorders use infrared LEDs to provide a night-vision mode. Hunters may use similar equipment to spot game at night, and some companies sell flashlights with an infrared LED to provide extra illumination for night-vision cameras or devices.
4.Robots may use an infrared LED to detect objects, and some utility meters even have an infrared LED to transmit data to a tool for easy meter reading.
Object Detection using IR light
It is the same principle in ALL Infra-Red proximity sensors. The basic idea is to send infra red light through IR-LEDs, which is then reflected by any object in front of the sensor.
For detecting the reflected IR light, we are going to use a very original technique: we are going to use another IR-LED, to detect the IR light that was emitted from another led of the exact same type.
This is an electrical property of Light Emitting Diodes (LEDs) which is the fact that a led Produce a voltage difference across its leads when it is subjected to light. As if it was a photo-cell, but with much lower output current. In other words, the voltage generated by the leds can't be - in any way - used to generate electrical power from light, It can barely be detected. that's why as you will notice in the schematic, we can use a Op-Amp (operational Amplifier) to accurately detect very small voltage changes.
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