Magnetic proximity switch
When the magnetic substance approaches the sensor, the sensor will act and output the sensor signal. In PLC control, this signal is used to determine the motion of the pusher and ejector cylinder to determine if the workpiece is pushed out or the cylinder is returned. The LED set on the sensor is used to display the signal status of the sensor for debugging purposes. When the sensor operates, the signal “1” is output; when the sensor is not activated, the LED does not light, and the signal “0” is output. The installation position of the magnetic switch sensor is adjusted by loosening the set screw of the magnetic switch, allowing the magnetic switch to slide in the slide rail of the cylinder, and after reaching the designated position, tighten the set screw again.
The function of the proximity switch is to send a signal when an object approaches the proximity switch and reaches a certain distance. It does not require the application of external force, is a non-contact main commander. Its use has far exceeded the trip control and limit protection provided by the trip switch.
Proximity switches can be used for high-speed counting, detection of the presence of metal bodies, speed measurement, level control, detection of part sizes, and use as contactless buttons.
The proximity switch can be divided into the following types according to the working principle:
1, high-frequency oscillation type: to detect various metal bodies
2. Capacitive type: used to detect various conductive or non-conductive liquids or solids
3, photoelectric type: used to detect all opaque substances
4, ultrasonic type: used to detect substances that do not transmit ultrasound
5, electromagnetic induction type: used to detect magnetic or non-magnetic metal
Inductive proximity sensors consist of three major components: an oscillator, a switching circuit, and an amplifier output circuit.