Single pole double throw intermediate stop button switch XT-13A
Push button switch refers to the switch that uses the push button to push the transmission mechanism, make the dynamic contact and static contact on or off, and realize the circuit replacement. Push button switch is a kind of master electrical appliance with simple structure and wide application. In the electric automatic control circuit, it is used to send control signals manually to control contactors, relays, electromagnetic starters, etc.
Button switch, also known as control button (button for short), is a low-voltage electrical appliance that can be reset manually and automatically. Buttons are usually used to send start or stop commands in the circuit to control the on and off of the coil current of electromagnetic starters, contactors, relays and other electrical appliances.
Push button switch is a kind of electrical appliance that acts when pressed and resets when released, which is used to turn on and off small current circuits. It is generally used in the control circuit with AC / DC voltage below 440V and current less than 5A. Generally, it does not directly operate the main circuit, but can also be used in interconnected circuits.
In actual use, in order to prevent misoperation, the buttons are usually marked or painted with different colors, including red, yellow, blue, white, black, green, etc. Generally, red indicates the operation under the condition of "stop" or "danger"; Green means "start" or "on". The emergency stop button must be a red mushroom head button. The button must have a metal protective retaining ring, and the retaining ring shall be higher than the button cap to prevent accidental touch of the button and misoperation. The material of the button board and button box for installing the button must be metal and connected with the main grounding bus of the machine.
There are many types of button switch structures, which can be divided into ordinary button type, mushroom head type, self-locking type, self resetting type, rotary handle type, with indicator light type, with light symbol type and key type, including single button, double button, I button and different combination forms. Generally, it adopts ponding structure, which is composed of button cap, return spring, static contact, moving contact and shell. It is usually made into composite type, with a pair of normally closed contacts and normally open contacts. Some products can increase the number of contacts through the series connection of multiple elements. There is also a self-contained button, which can automatically maintain the closed position after being pressed, and can only be opened after power failure.