Photoelectric Switch With On And Off Delay Function
Photoelectric switch (photoelectric sensor) is the abbreviation of the photoelectric proximity switch, it is the use of objects to detect the beam or reflection, by the synchronous loop gating circuit to detect the presence of objects. The object is not limited to metal, and all objects that reflect light can be detected. The photoelectric switch converts the input current into an optical signal on the transmitter. The receiver then detects the intensity of the received light or the presence or absence of the target object. Most of the photoelectric switch is selected near the wavelength of visible light infrared light wave.
Photoelectric switch is composed of transmitter, receiver and detection circuit composed of three parts. The emitter is aimed at the target beam, and the emitted beam is typically derived from a semiconductor light source, a light emitting diode (LED), a laser diode, and an infrared emitting diode. The beam is emitted continuously, or the pulse width is changed. The radiation intensity of the pulsed modulated beam is selected several times during the launch and runs unobstructed towards the target. Receiver has a photodiode or photoelectric transistor, composed of photovoltaic cells. In front of the receiver, there are optical elements such as lenses and iris. Behind it is the detection circuit, which filters out the effective signal and applies the signal. In addition, the structural components of the photoelectric switch also have a transmitting plate and an optical fiber. Triangular reflector is a solid structure of the launch device. It consists of a small triangular pyramidal reflective material that enables the beam to be accurately returned from the reflector, which is of practical significance. It can change the firing angle in the range of the optical axes 0 to 25 so that the beam is almost returned from an emission line, after reflection, or from the reflection line.
The photoelectric switch generally has a good hysteresis characteristic, so that even if the object is shaken in a small range does not affect the output state of the driver, so that it can be maintained in a stable work area. At the same time, the self-diagnosis system can also display the light receiving state and stable working area to monitor the work of the photoelectric switch at any time.
Photoelectric switch according to the structure can be divided into amplifier separation, amplifier built-in and power storage type three.
(1) amplifier separation is the amplifier and the sensor separation, and the use of special integrated circuits and hybrid installation process, the sensor has a very small and multi-species characteristics, and the amplifier more features. Therefore, the type of terminal block connection, and can be, DC power supply common. With the on and off delay function, you can set the light, the sound switch, can control the six kinds of output status, both contact and level output.
(2) amplifier built-in amplifier and sensor integration, the use of special integrated circuits and surface mount technology, the use of DC power supply work. The response speed of the situation (both 0.1ms and 1ms), can detect small and high-speed moving objects. Change the power polarity can be converted bright, dark, and can be set from the self-diagnosis stable work area indicator. Both voltage and current output of two ways to prevent mutual interference in the system installation is very convenient.
(3) power storage type is the amplifier, sensor and power supply integration, the use of special integrated circuits and surface mount technology. It is generally used AC power, suitable for the production site to replace the contact stroke switch, can be directly used for strong electric control circuit. Can also set self-diagnosis stable work area indicator, the output with SSR solid state relay or relay normally open, normally closed contacts, to prevent mutual interference, and can be installed in the system closely.