Photo LED (Wiring Diagram)

Activation by clicking on the switch

Function

Like the light-emitting diode, the photodiode has the capability of switching through the circuit in only one direction. In addition, it still depends on the external influx of light energy. For this reason, it is used for photoelectric barriers. Then, instead of the light-emitting diode, the signal is processed; e.g., the doors of a lift are opened/closed.It can not only generate a yes/no signal, but can, more or less, control the current flow according to the incoming light energy. Thus, one can determine with photodiodes, apart from measuring using infrared beams, e.g., also the clouding in the exhaust gas flow of diesel engines.

Future

The diode is well known as a photoelectric barrier with which an infrared source of light from one side, shines onto a photosensitive semiconductor on the other side. This infrared light beam can be also used to explore the surroundings of a vehicle. The advantage compared with the radar technology is, in this case, the concurrent processing of several pixels. If this is done in various levels, one receives a three-dimensional image. 09/09