Common problems of photoelectric switches

The photoelectric switch is the abbreviation of the photoelectric proximity switch. It uses the shielding or reflection of the measured object and the beam to connect the circuit through a synchronization circuit to detect the existence of the object. Objects are not limited to metals, all objects that reflect (or block) light can be detected. So, what are the common faults of the ball switch photoelectric switch?

Ball switch

1. Start and burn the fuse, the output voltage is zero. This is usually caused by the fault of the switch tube, the short circuit of the emitter and the collector. At this time, you can remove the switch tube first, measure the resistance of the emitter and collector of the switch tube to ground, if it is zero or very small, you can replace it. However, you also need to check whether there are problems with other components before you can open it.

2. The grating has "S"-shaped distortion. This problem should be concentrated on the filter circuit and the voltage regulator circuit, usually because of the diode open circuit, from the full-wave rectifier to the half-wave rectifier, which may also be due to the filter capacitor Caused by lowering.

3. The filter circuit of the AC 220 V rectifier has a short-circuit failure, and starts and burns the insurance. First check whether the rectifier diode is short-circuited and the filter capacitor leaks seriously. You can also pull out the degaussing coil to check whether the degaussing thermistor has a short-circuit fault. If there is a fault, it should be replaced.

4. No grating, no display, no power indicator, but no burn insurance. At this time, check whether the AC mutual inductance transformer is turned on, whether the current limiting resistor of the rectifier circuit has an open circuit (burning) fault, or whether the rectifier diode is turned on.

5. There is no grating in the machine, no display, no abnormal sound. If the "squeak" sound indicates that the vibration frequency is low, check the vibration-related parts, such as the "tap" sound, which indicates the overcurrent protection of the power supply, and the overcurrent protection circuit.