Push button category
Before you start the article, tell a story. Compared to when you used a ballpoint pen, you must have tried it and clicked it to go in. I don't know if you have thought about why this is happening, or you can take the ballpoint pen apart and find out. In fact, it is the structure of the structure. This article discusses the composition of the button switch similar to the ballpoint pen to guide the mystery!
The structure of the push button: consists of a button cap, a return spring, a fixed contact, a movable contact, a housing and a strut link.
Metal button switches are mainly classified as follows
1. Normally open contact (moving contact): refers to the contact in the original state (the appliance is not subjected to external force or the coil is not energized), and the fixed contact and the movable contact are separated.
2. Normally closed contact (moving contact): refers to the contact in the original state (the appliance is not subjected to external force or the coil is not energized), and the fixed contact and the movable contact are in a closed state.
3. Normally open (push) push button, when not pressed, the contact is open, the contact is closed when pressed; when released, the push button is reset and disconnected under the action of the return spring. In the control circuit, the normally open button is often used to start the motor, also called the push button.
4. The normally closed (open) push button is opposite to the normally open push button. When the button is pressed, the contact is closed, and the contact is broken when pressed; when the hand is released, the push button is under the action of the return spring. Reset closed. The normally closed push button is often used to control motor parking, also known as self-resetting push button.
5. Composite push button: A push button that combines a normally open and normally closed button switch, that is, 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 first disconnected, and the normally open contact is closed, which can be regarded as a self-locking push button; when released, the push button is firstly opened by the return spring under the action of the return spring. Open, and then close the normally closed contact. The composite push button is used in the interlock control circuit.