Red key switch 6.2 * 6.2 * 2.5 direct insertion light touch switch. There are many types of light touch key switch structures, which can be divided into ordinary push 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, etc. There are single button, double button, three button and different combination forms, which are composed of button cap, reset spring, bridge contact and shell, etc. They are usually made of composite type, with a pair of normally closed contacts and normally open contacts, Some products can increase the number of contact pairs by connecting multiple components in series. There is also a self holding button that can automatically remain in the closed position after being pressed, and can only be opened after power is cut off. The button switch can complete basic controls such as start, stop, forward and reverse rotation, speed change, and interlocking. Usually, each button switch has two pairs of contacts. Each pair of contacts consists of one normally open contact and one normally closed contact. When the button is pressed, both pairs of contacts act simultaneously, causing the normally closed contacts to open and the normally open contacts to close. In order to indicate the function of each button and avoid misoperation, the button cap is usually made into different colors to indicate differentiation, including red, green, black, yellow, blue, white, etc. For example, red represents the stop button, green represents the start button, etc. The main parameters, type, installation hole size, number of contacts, and current capacity of the button switch, which can be disconnected as soon as the circuit is released by hand. Of course, the inching switch can also form a self-locking switch through a self-locking circuit. Two inching switches and a self-locking circuit can form a self-locking switch, but this form is more complex than mechanical self-locking switches and requires professional knowledge. So it is only suitable for specific occasions. What is the difference between a single button self-locking switch and an unlocked switch? A self-locking switch is a mechanical device that locks its circuit switch state through the switch itself. When it comes to button switches in our daily life, it is probably well-known to everyone. This type of switch has two structures: one press to turn on self-locking, another press to turn off and reset, and the other press to turn off and reset without locking (unable to lock, turned on when pressed, reset when released). What are the common types of button switches? The multi key combination key switch is divided into structural types such as self-locking, interlocking, and unlocked. The eight button or twelve button switch was early used as a program preselection switch in televisions, while the four button switch was early used as a washing state selection switch in wave wheel washing machines.