Limit switch, close to switch the two position switch is in the equipment industry common switch, according to the different site has different choices. The advantages and disadvantages of them . A comparison:

The proximity switch : no need to touch the object detection, eddy current metal detection objects caused by electromagnetic induction in a way to detect objects, such as HWL HTL-Q05N1E uses this principle to detect ferromagnetic objects, detection distance 5MM, 10-30vdc power supply, and is 1, non-contact, so it won't wear and the inspection object damage. 2, with no contact output mode, so life is prolonged, the output of the NPN/PNP, .3 isn't affected by detecting objects and oil stains, water docking point of life without influence, only the magnetic induction. 4, the response speed of up to 3KHZ

Disadvantages: 1, according to the detection of objects of different materials, the detection distance has significant differences, the general object detection for non magnetic metal ( such as aluminum), so the detection distance is smaller

2, mutual interference refers to the adjacent sensor magnetic ( or capacitance ) influence, output in an unstable state

3, close to the sensor OFF, due to the operation of the circuit and a small amount of leakage current, therefore, occur within a small amount of residual current load ( load residual voltage ), the load reduction of adverse

The limit switch is a contact switch, to realize the switch function using mechanical switching contacts. For example, SL1-A, single contact limit switches, LDVS-5204 is the 2 contact limit switches, LDVS-5414 is the 4 contact limit switches

Advantage.

1 no matter what material, as long as the operation contact force reaches a certain value, start switch.

2 the contact output mode, with the external voltage is different and different output, no leakage phenomenon.

3, not to be influenced by the adjacent sensor, output stability.

Disadvantages:

1 contact, so will wear and damage detection of objects, precise object does not recommend the use of the method

2, contact, limited mechanical life.