LTH 1550-01 IR Transmitter Reciever module

LTH 1550-01 reflective object sensor combination of Infra-red emitting diode and an NPN silicon phototransistor. These are mounted side by side on a converging optical axis in a black plastic housing. This IR LED consists of two parts, a Transmitter, and a Receiver. The transmitter emits IR light, and the object reflects that light. The IR led inside the reflective sensor is forward biased, the sensor transmits IR rays. These rays get reflected back when it hits on an object/obstacle. The phototransistor (receiver) receives the reflected light. As soon as the light falls on the phototransistor, it starts conducting. As a result, the collector current increases and the collector voltage decreases.

The amount of reflection and reception varies with distance. These differences cause a change in the input and are thus used for proximity detection. IR LED sensor module has both the transmitter and emitter designed to work on the 940 nm wavelength. 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 phototransistor 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 phototransistor. The amount of reflected light depends upon the colour of the reflected surface.

Applications:

• Counter Circuits
• Obstacle Detection
• Obstacle Avoidance Robot
• Line Follower Robot
• Finger Heart Rate Monitor