The control button is a simple structure and widely used manual master electrical appliance, It can be used with or in conjunction with the realization of remote automatic control for realizing the interlock of the control line.
As shown in Figure 1, the control button is composed of a button cap, a reset spring, a bridge contact and a housing, etc., usually made of compound type, that is, with normally closed contact and normally open contact. When press the button, disconnect the normally closed contact first, and then connect the normally open contact; After the button is released, under the action of the reset spring, the button contacts automatically reset in the opposite order. Usually, in the absence of special instructions, the contact action sequence of contact appliances is "break first and then close".
1- Button cap 2- reset spring 3- dynamic contact 4- normally open static contact 5- normally closed static contact
In the electrical control circuit, the normally open button is commonly used to start the motor, also known as the start button, the normally closed button is often used to control the motor to stop, also known as the stop button, and the composite button is used in the interlock control circuit.
There are many types of control buttons, including press-button type, emergency type, key type, knob type, lamp type and break in structure
