IR Receiver Black 3mm

IR Photodiode functions as an IR receiver used to detect the light rays reflected from an IR LED.  The photodiode is basically a reverse-biased PN junction diode. When the photodiode is exposed to light, the electrical resistance across the diode decreases. Thereby increasing the reverse current. In case if the photodiode is not exposed to light, the resistance across the diode will be high. Hence the reverse current will be extremely small. This current is also known as a dark current.

When light falls on the surface of a photodiode, a sufficient amount of energy is acquired by the electrons to break the covalent bond. Thus free electrons and holes are created. These free electrons will increase the reverse current. The basic circuit of an IR sensor consists of an IR led and IR photodiode. During the forward-biased state, the IR transmitter LED will be emitting IR rays. IR rays from LED get reflected back when an obstacle is detected and the IR receiver will capture these rays. Finally, the IR receiver will conduct producing an active low output.

In an IR LED the type of incidence can be direct incidence or indirect incidence. Thus in the case of direct incidence, the IR LED is placed in front of the photodiode without any obstacle in between. Whereas in indirect incidence, both the diodes are placed side by side with an opaque object in front of the sensor. The light from the IR LED hits the opaque surface and reflects back to the photodiode. The amount of reflected light depends upon the colour of the reflected surface. This Infrared led comes in a 3 mm diameter. Moreover, these Transmitter and Receiver pairs are used as colour sensors, distance sensors, object sensors, line follower sensors, etc.

Applications:

• Obstacle Avoidance Robot
• Flame Sensor
• Anti-Falling Robot
• Object Detection Module
•  IR Proximity Sensor