The working principle of photoelectric switch
After the modulated pulse generated by the oscillation circuit passes through the reflection circuit, the light pulse is radiated from the luminous tube GL. When the measured object enters the range of the light receiver, the reflected light pulse enters the photosensitive transistor DU. And in the receiving circuit, the optical pulse is demodulated into an electrical pulse signal, then amplified by an amplifier and synchronized gating and shaping, and then the interference is eliminated by digital integration or RC integration, and finally after a delay (or no delay), the driver is triggered to output the photo Switch control signal.
Photoelectric switches generally have good hysteresis characteristics, so even if the detected object shakes in a small range, it will not affect the output state of the driver, so that it can be kept in a stable working area. At the same time, the self-diagnostic system can also display the light receiving state and stable working area to monitor the work of the photoelectric switch at any time.
Features of photoelectric switch
With self-diagnosis and stable working area indication function, it can inform in time whether the working status is reliable;
Opposite-beam, reflective, and mirror-reflective photoelectric switches have the function of preventing mutual interference and are easy to install;
The setting of ES external synchronization (external diagnosis) control terminal can pre-check whether the photoelectric switch is working normally before running. It can accept interruption or detection instructions from the computer or programmable controller at any time, and the appropriate combination of external diagnosis and self-diagnosis can make the photoelectric switch intelligent;
The response speed is fast, the response speed of the high-speed photoelectric switch can reach 0.1ms, and it can perform 300,000 detection operations per minute, which can detect small objects moving at high speed;
Using ASIC and advanced SMT surface mounting technology, it has high reliability;
Small size (minimum only 20×31×12mm), light weight, simple installation and debugging, and short circuit protection function.