The construction parameters of the button switch
Button switch: an electrical appliance that turns on or off a small current circuit for a short time. It does not directly control the on and off of the main circuit, but sends out manual "commands" in the control circuit to control electrical appliances such as contactors, relays, and so on. To control the main circuit, it is called the "master electrical appliance".
The appearance of the button switch
The structure of the button switch: It is composed of a button cap, a return spring, a fixed contact, a movable contact, a shell and a pillar connecting rod.
Normally open contact: refers to the contact where the fixed contact and the movable contact are separated in the initial situation. Normally open button switch
, when not pressed, the contact is open, when pressed, the contact is closed and connected; when released, the button switch is reset and opened under the action of the reset spring. In the control circuit, the normally open button is often used to start the motor, also known as the start button.
The normally closed button switch
is the opposite of the normally open button switch. When it is not pressed, the contact is closed, and when it is pressed, the contact is disconnected; when the hand is released, the button switch is reset and closed under the action of the reset spring. The normally closed button is often used to control the parking of the electric motor, also called the parking button.
Compound button switch: a button switch that combines a normally open and a normally closed button switch
, that is, it has a normally closed contact and a normally open contact. When not pressed, the normally closed contact is closed, and the normally open contact is open. When the button is pressed, the normally closed contact is firstly disconnected, and the normally open contact is closed; when released, the button switch
will firstly disconnect the normally open contact and then close the normally closed contact under the action of the return spring , The compound button is used in the interlock control circuit.