A4TS-M18-P8, A4TS-M12-P4-180 proximity switches

A4TS-M18-P8, A4TS-M12-P4-180 proximity switchesWide voltage - waterproof, high temperature resistant, replaceable small switches and limit switches. It is composed of sensors, oscillators, switches, outputs, and stabilized power supplies. After the electronic circuit is installed and adjusted, it is sealed with epoxy resin and has good moisture-proof and anti-corrosion properties.

When working, turn on the power and the oscillator will start oscillating immediately. When a metal object enters the magnetic field of a high-frequency oscillator oscillating at a certain stable frequency, eddy current losses are generated inside the metal object, causing hysteresis losses to the ferromagnetic object, increasing the resistance of the oscillation circuit and energy loss, resulting in weakened oscillation until it stops. Oscillation and stop oscillation are two different states, which are converted into binary switch signals through switches and outputs connected to the oscillation circuit, sending out signals to detect metal objects, and outputting corresponding control signals to control relays or other electrical appliances.

Proximity switch is a non-contact industrial automation accessory product used in PLC control systems. It is a new type of switch component that can achieve non-contact detection, control, and output switch signals to control equipment. Its working principle mainly uses metal for detection, and when the switch approaches a metal object, it emits an induction signal. When the metal target approaches this magnetic field without changing and reaches the induction distance, eddy currents are generated inside the metal target, causing oscillation attenuation and even stopping. The changes in oscillator oscillation and stop oscillation are processed by the post amplification circuit and converted into switch signals, triggering the driving control device to achieve non-contact detection.

Proximity switches, commonly known as contactless travel switches, are widely used in material sorting control systems and automatic detection. The proximity switches we commonly use include eddy current type, capacitive type, photoelectric type, Hall type, etc. They can detect the presence of objects approaching within a range of a few millimeters to tens of millimeters. When the distance between the object and the proximity switch reaches a certain range, it can emit a corresponding "action" signal. The core part of a proximity switch is the "sensing head", which has a high ability to sense and distinguish approaching objects.

Proximity switches, commonly known as contactless travel switches, are widely used in material sorting control systems and automatic detection. The proximity switches we commonly use include eddy current type, capacitive type, photoelectric type, Hall type, etc. They can detect the presence of objects approaching within a range of a few millimeters to tens of millimeters. When the distance between the object and the proximity switch reaches a certain range, it can emit a corresponding "action" signal. The core part of a proximity switch is the "sensing head", which has a high ability to sense and distinguish approaching objects.

Difference between PNP and NPN proximity switches

The high and low levels of PNP and NPN output signals are different

First, let's talk about the meanings represented by PNP and NPN. PNP type indicates that the signal output terminal outputs a high-level output, and the internal switch is connected between the signal terminal and the positive terminal; NPN type indicates that the signal output terminal outputs a low-level output, and its internal switch is connected between the signal terminal and the negative terminal.

The wiring methods of PNP and NPN are different

Taking a three wire output proximity switch as an example, there are differences in the wiring methods for PNP and NPN normally open proximity switches. When the proximity switch is PNP type, the black and blue wires are connected to the negative terminal of the power supply. When the proximity switch is activated, the blue and brown wires are connected to obtain a signal at both ends of the load; When the proximity switch is of NPN type, the black wire and brown wire are connected to the positive pole of the power supply in parallel. When the proximity switch is activated, the blue (negative) wire and black wire are connected to receive a signal at both ends of the load. The wiring diagram is shown below.

Therefore, the specific method of wiring them is: when the NPN type three wire proximity switch is in a low-level output mode. Connect brown to positive, blue to negative, and black to the input terminal; When the PNP type three wire proximity switch is in a high-level output mode. Connect the brown wire to the positive pole, the blue wire to the negative pole, and one end of the black wire to the PLC input terminal.

Regarding maintenance and upkeep of proximity switches:

In order to ensure the long-term stable operation of the proximity switch, like general control machines, please perform the following regular checks

1. Check whether the installation position of the object and proximity switch is offset, loose, deformed, etc

2. Check for looseness, poor contact, or broken wires in the connecting parts of the wiring

3. Is there any accumulation of sticky metal dust or other substances

4. Check for any abnormalities in temperature conditions, surrounding environmental conditions, etc

5. Check for any abnormalities in the distance

A4TS-M18-P8, A4TS-M12-P4-180 proximity switchesKey Features

Using dedicated ICs to improve product anti-interference performance
Built in power reverse protection circuit
Built in surge protection circuit
Built in overcurrent protection circuit
Long lifespan, high reliability, economical and easy to operate
The working status of the proximity switch can be confirmed through the red LED light
IP67 protection level (IEC specification)
Widely applicable, can replace micro switches and limit switches

Selling inductive sensors: metal casing, threaded cylindrical shape, DC 2-wire, 3-wire, 4-wire, AC 2-wire, AC/DC 2-wire, yellow LED indicator light, red LED indicator light, IP67 protection level, fully threaded proximity switch, plug-in proximity switch, wired proximity switch, square proximity switch, corner pole proximity switch, planar proximity switch, diameter 8mm proximity switch, diameter 12mm proximity switch, diameter 18mm proximity switch, diameter 30mm proximity switch, PNP proximity switch, NPN proximity switch.