An Analysis of the Basic Circuit Principle of Push Button Switches
Push Button Switches is used to intercept and connect the control circuit of the low-voltage switch appliances. The contact current of the Push Button Switches is rated at 5A. Therefore, the operation of the Push Button Switches is controlled by the circuit to the small current circuit.
Button has a single pole two-bit switch or bipolar two-position switch, it is kinetic energy and use is divided into start button, reset button, view button, control button, limit button and so on.
The Push Button Switches has a moving (normally open) and dynamic (normally closed) points.
Micro-button with conductive rubber or metal sheet as a conductor, can be used as condition selector switch for small semiconductor radio, remote control, checkout and other products.
Push Button Switches: a short-term on or off the small current circuit of the electrical appliances, it does not directly control the main circuit off, and in the control circuit issued a manual "command" to control contactors, relays and other electrical appliances, and then by them To control the main circuit, so called "master electrical".
The appearance of the Push Button Switches
1. The structure of the Push Button Switches
Push Button Switches structure: by the button cap, reset the spring, fixed contact, movable contact, shell and pillar connecting rod and so on.
Normally open contact (moving contact): refers to the initial situation (electrical appliances are not external or coil is not energized), fixed contact with the movable contact in the separation of the contacts.
Normally closed contact (moving contact): refers to the initial situation (electrical appliances are not subject to external force or coil is not energized), fixed contact with the movable contact in the closed contact.
Normally open (switch) Push Button Switches, when not pressed, the contact is broken, press the contact closed when connected; when released, the Push Button Switches in the role of reset the return of the spring off. In the control circuit, normally open button is often used to start the motor, also known as the launch button.
Normally closed (switch off) Push Button Switches and normally open Push Button Switches, the end of the press, the contact is closed, press the contact when the disconnect; when the hand is released, the Push Button Switches in the role of reset the return of the closed The Normally closed buttons are often used to control motor parking, also known as parking button.
Composite Push Button Switches: normally open and normally closed Push Button Switches combination as one of the Push Button Switches, that is, normally closed contact and normally open contact. When not pressed, the normally closed contact is closed and the normally open contact is disconnected. When the button is pressed, the normally closed contact is disconnected, and the contact is closed. When the button is released, the Push Button Switches is turned off under the action of the return spring, and the normally closed contact is closed. The The composite button is used in the interlock control circuit.
In the button is not allowed to use a multimeter to measure, pass, press the button nowhere that is often closed, nowhere, press the button that is often open point.
Push Button Switches normally open normally closed because some occasions need to use normally open contacts, and some occasions need to use normally closed contacts, such as the use of buttons to start with normally open, stop button to use normally closed, in order to be universal, Push Button Switches is usually equipped with often Open and normally closed the two contacts (constitute a normally open contact, a normally closed contact), it and our Push Button Switches, the difference is that the button a loose contact to reply to the situation when not pressed Stick the button). Button can not afford maintenance.
Push Button Switches is a circuit breaker, from the load maintenance, short circuit maintenance effect, after closing, if there is no fault situation, has always adhered to the closed state, unless people put it open.
Push Button Switches selected normally closed reasons:
1. From the moment of action
The normally closed contact is much shorter than the normally open contact from the natural condition to the closed time. Perhaps you want to say, how much less how much? Such a short time does not matter. But I would like to say that this is particularly important when the risk appetite is urgent.
At this time, then a short time, even if the millisecond and even microsecond time is also very important. In such a short time, you use the normally open contact may not stop the machine or disconnect the switch, the formation of a serious machine damage or personal injury. But the use of normally closed contact may have the machine to stop or make people instantaneous short time to prevent all this attack.
2. From the button organization
Emergency stop button Whether it is normally closed or normally open contact, do not press the place (according to the case), will start from scratch, so that the action to effect. When using the normally open contact, when the emergency stop button is not in place, the emergency stop is not to achieve any effect (due to open contact is not closed); and the use of normally closed contact is not the same, regardless of emergency stop Button press not in place, only by contact action, and emergency stop on the effect of the.