The work principle of the photo electric sensor (principle of infrared led sensor)
The ir led sensor is made by change of light intensity converted into the electrical signal and to achieve control of other device。in general the ir led sensor are divided into: transmitter receiver and detection circuitThe transmitter emits a light beam to the target, In generally the beam of light emitted from the semiconductor light source, such as light emitting diode (LED), laser diodes and infrared emitting diode(ir led). Beam launch continuously, or change the pulse width. The receiver has a photodiode, a photoelectric triode, light battery. In front of the receiver, with optical components such as lenses and aperture etc.. Behind of the detection circuit, it can filter out the effective signal and the application of the signal.In addition, the structural of the photoelectric switch has transmitter board and the optical fiber.Triangle reflecting plate is launching device firm structure. It consists of a triangularrcone reflecting material is very small, can make the beam accurately returned from thereflecting plate, has the practical significance. It can be in the 0 to 25 range and the optical axis changing emission angle, so that the beam is almost the rays from a root,after reflection, it’s will be returns from the roots of anti ray.Classification and working style
⑴ The tank type photoelectric sensor
A light emitter and a receiver face to face arranged on both sides of a groove is a groove shape photoelectric. Light emitting device emits infrared or visible light, in the absence of resistance under the condition of light receiver can receive the light. But when the detected object go through the groove and the light is blocked, the photoelectric switch action. The output a signal of switch control, switching on and off load current, thus completing a control action. The detection distance of groove shaped switch just only has only a few centimeters. Be case of the structure.
The correlation type ir led sensor
If the light emitting device and receiving device is separated, can make the detection distance is increased. By a light emitting device and a light receiving device is composed of a photoelectric switch is called a shot of the separation type photoelectric switch, referred to as the opposite type photoelectric switch. Its detection distances of up to a few meters or even tens of meters. When using the light emitting device and a light receiving device are arranged in the detected object through the path on both sides respectively, detection through to block the light path, a light receiving device will be output a switch control signal.
The reflection type ir led switchThe light emitting device and a light receiving device in a device, mount a reflecting plate in front of it, complete the photoelectric control function using the reflection principle，this is called reflection plate type (or mirror reflection type photoelectric switch). Under normal circumstances,
The receiver receiving the lights from the emitting device with the reflected light plate; once the object to be detected is blocked, the light receiving device receives no light, a photoelectric switch on the action, the output a signal of switch control.