Push-button switch refers to a switch that uses a button to push the transmission mechanism to make the moving contact and the static contact press on or off and realize circuit switching. The push button switch is a kind of master electrical appliance with simple structure and wide application.

In electrical automatic control circuits, it is used to manually issue control signals to control contactors, relays, electromagnetic starters, etc.
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There are many structural types of push button switches, which can be divided into ordinary button type, mushroom head type, self-locking type, self-resetting type, rotary handle type, indicator type, lamp symbol type and key type, etc.

There are single Button, double button, triple button and different combinations are generally made of building block structure, composed of button cap, return spring, bridge contact and shell, etc., usually made of composite type, with a pair of normally closed contacts and normally open Contact, some products can increase the number of contact pairs by connecting multiple components in series. There is also a self-contained button that automatically maintains the closed position when pressed, and can only be opened when power is removed.

What is a key switch

The button switch can complete basic control such as start, stop, forward and reverse rotation, speed change and interlock. Usually each push button switch has two pairs of contacts. Each pair of contacts consists of a normally open contact and a normally closed contact. When the button is pressed, the two pairs of contacts act simultaneously, the normally closed contact is disconnected, and the normally open contact is closed.
In order to indicate the function of each button and avoid misoperation, the button caps are usually made of different colors to show the difference. The colors are red, green, black, yellow, blue, white, etc. For example, red means stop button, green means start button, etc. The main parameters, type, installation hole size, number of contacts and current capacity of the contacts of the push button switch are detailed in the product manual.

The meaning of the button switch model

Buttons can be classified according to operation mode and protection mode. Common button categories and characteristics:

Open type: suitable for embedded and fixed on the switch board,
Button switch on the panel of the control cabinet or console. Codenamed K.
Protective type: with a protective shell, which can prevent the internal button parts from being mechanically damaged or touching the live parts, the code is H.
Waterproof: With a sealed casing, it can prevent the intrusion of rainwater. Codenamed S.
Anti-corrosion type: can prevent the intrusion of chemical corrosive gases. Codenamed F.
Explosion-proof: It can be used in places containing explosive gas and dust without causing explosion, such as coal mines and other places. Codenamed B.
Knob type: The contact is rotated by hand, with two positions on and off, generally panel-mounted. Codenamed X.
Key type: The key is inserted and rotated for operation, which can prevent misoperation or be operated by special personnel. Codenamed Y.
Emergency type: there is a big red mushroom button protruding outside,
Self-sustaining button: The button is equipped with a self-sustaining electromagnetic mechanism, which is mainly used in power plants, substations or test equipment. Codenamed Z.
Illuminated button: The button is equipped with a signal lamp, which is used for issuing operation commands and also serves as a signal indication, and is mostly used on the panels of control cabinets and consoles. Codenamed D.