一、 Limit switch description

Limit switch is mainly used in equipment position detection, opening detection, over-limit protection and so on

二、switch types, mechanical switches are divided into the following three types:

1, pendulum rod type

2、Micromotion

3, direct action

三、What is SPDT and DPDT?

SPDT: single pot double throw, with 1 pair of contacts NC+NO, can output 2 switching quantities DPDT: double pot double throw, with 2 pairs of contacts 2x (NC+NO), can output 4 switching quantities.

Each single-pole double-throw switch has three terminals connected to two contacts and a knife

四、 what is dry contact, wet contact?

Usually mechanical switches are dry contacts, and proximity switches are wet contacts.

When we need proximity, dry contact magnetic switch, we can choose TOPWORX and WESTLOCK two brands such as go switch 73 series

1, wet contact: active switch, with power and no power of two states, there is polarity between the two contacts, can not be reversed;

2, dry contact: passive switch, reaction line switch and closed two states, 2 contact no polarity can be exchanged. Has a certain capacity.