How to connect a three-wire proximity switch instead of a two-wire proximity switch?

Switches have two-wire, three-wire and four-wire systems, which are divided into DC and AC. Compared with the two-wire system, the three-wire proximity switch actually has independent zero lines, namely power supply, signal feedback and zero line. The two-wire system has only power supply and signal feedback. Just don't connect the zero line.

The two-wire system is connected in series with the load, and the three-wire system is generally a brown wire connected to the positive electrode, a blue wire connected to the negative electrode and a black or yellow wire connected to the load. For example, NPN type: the output level is low, brown is positive, blue is negative and black is connected to the load, and the load outlet is connected to the positive electrode, while PNP type is the opposite.

Two wires of the three-wire proximity switch are connected with a DC24V power supply, and the other wire is a signal wire; One line of the two-wire proximity switch is connected to the DC24V power supply, and the other line is the signal line. The two-wire loop must be loaded with its allowable current before it is connected to the power supply.

Extended data

Proximity switch, also called contactless proximity switch, is an ideal electronic switch sensor. When the metal detector approaches the sensing area of the switch, the switch can quickly send out electrical instructions without contact, pressure and sparks, and accurately reflect the position and stroke of the moving mechanism;

Even if it is used for general travel control, its positioning accuracy, working frequency, service life, convenience of installation and adjustment and adaptability to harsh environment are incomparable to general mechanical travel switches. Widely used in machine tools, metallurgy, chemical industry, textile, printing and other industries. It can be used as limit, counting, positioning control and automatic protection in automatic control system.

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