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Buttons have a wide range of uses, such as starting and stopping of lathes, forward rotation and reverse rotation, etc.; start, stop, rise, fall, forward, backward, left, right, slow or fast operation of tower cranes, etc., all need buttons control.
The push button switch refers to a switch that uses a button to push the transmission mechanism to make the moving contact and the static contact press on or off and realize the circuit switching. The push button switch is a kind of master electrical appliance with simple structure and wide application. In electrical automatic control circuits, it is used to manually send control signals to control contactors, relays, electromagnetic starters, etc.
The button switch may be the simplest component in the electrical circuit, but it controls the lifeblood of the entire control circuit, so it is also called the "master switch". Understanding all kinds of button switches and using them skillfully and flexibly can make us get twice the result with half the effort.
Button switches are used to switch on or off small current circuits in a short period of time, and are mainly used in electrical control circuits. The current allowed to flow through the button switch is small, generally not more than 5A.
The button is generally composed of a button cap, a return spring, a bridge-type moving contact, a static contact, a pillar connecting rod, and a housing. The opening and closing state of the contacts when the button is not subjected to external force (that is, static), is divided into a stop button (that is, a dynamic break button), a start button (that is, a dynamic close button) and a reset button (that is, a combination of a dynamic close and a dynamic break. integrated button). When the button is under the action of external force, the opening and closing state of the contact changes: the normally open contact under static state is closed, and the normally closed contact under static state is open.
Start and stop button switch, generally used for start and stop. Generally, there are green, red, yellow and so on. We usually use the green button as start, the red button as stop, and the yellow button as jog.
In fact, their internal structure is the same.
See the start, pass, and reset in the first picture for the physical picture. The start and reset buttons are different from the pass button. The start and reset buttons are push button switches with indicator lights. The physical contact diagram is as follows:
Wiring problem with button switch
1. How to wire the button switch with light. There are five terminals on the button. Now I can only measure how to connect the power line, but I don’t know how to connect the light.
Answer: This situation is relatively simple. This kind of switch should have two terminals connected to the light, and the other three terminals are for switches. Find out the terminal connected to the light and the terminal of the switch, and then distinguish which two terminals you want to use to connect Switch, directly connect the light and the switch terminal to be connected in series, so that when the switch is turned on, the light will be on.
Classified according to the purpose and structure of the contact
(1) Normally open button
(2) Normally closed button
(3) Compound button classified according to operation mode and protection mode Buttons can be classified according to operation mode and protection mode, common button categories and characteristics:
(1) Open type: suitable for embedded and fixed on the panel of switch board, control cabinet or console.
(2) Protective type: with a protective shell, which can prevent the internal button parts from being mechanically damaged or people touching the live parts.
(3) Waterproof type: with a sealed shell, which can prevent rainwater from intruding.
(4) Anti-corrosion type: it can prevent the intrusion of chemical corrosive gases.
(5) Explosion-proof type: It can be used in places containing explosive gas and dust without causing explosion transmission, such as coal mines and other places.
(6) Illuminated button: There is a signal light inside the button, which is not only used to issue operation commands, but also serves as a signal indicator, and is mostly used on the panels of control cabinets and consoles.
(7) Key type: Insert and rotate with a key to operate, which can prevent be operated by a special person.
(8) Emergency type: There is a big red mushroom button protruding outside, which is used to cut off the power supply in case of emergency.
(9) Self-holding button: The button is equipped with a self-holding electromagnetic mechanism, which is mainly used in power plants, substations or test equipment. Operators communicate with each other and issue instructions, etc., and are generally panel-operated.
(10) Knob type: The contact is operated by rotating the handle, with two positions of on-off, generally panel-mounted.
(11) Combined type: combination of multiple buttons. (12) Interlocking type: Multiple contacts interlock with each other. Code-named off, on.
The main technical parameters
Switch rating: ac-15 36v/10a 110v/10a 220v/5a 380v/2.7a 660v/1.8a dc-13 24v/4a 48v/4a 110v/2a 220v/1a 440v/0.6a
Conventional thermal current: 1th 10a
Electric shock Resistance: ≤50mΩ
Insulation resistance: ≥10mΩ
Mechanical life: general button n≥100×10 times; knob ≥30×10 times.
Key button n≥5×10 times; emergency stop button ≥5×10 times
Signal indicator light, a device that uses light to monitor the working or position status of circuits and electrical equipment. It is also the most intuitive and unique monitoring component in automation equipment. The main function is usually used to reflect the working state of the circuit (with or without electricity), the working state of electrical equipment (running, outage or test) and position state (closed or disconnected), etc. To remind the operator to deal with the fault in time, or operate a certain function to complete the relevant action.
Push button switch, also known as control button (referred to as button), is a low-voltage electrical appliance that can be manually reset and generally automatically reset. Buttons are usually used in circuits to issue start or stop commands to control the on and off of electric coil currents such as electromagnetic starters, contactors, and relays.
Main functions: generally used in control circuits with AC and DC voltages below 440V and currents less than 5A, generally do not directly manipulate the main circuit, but can also be used in interconnected circuits. In order to control the operation of the equipment, stop, pause or reset and other functions.
Waterproof push button switches, as the name suggests, are switches that can be operated with wet hands. In some humid environments, it can be used with confidence because it has good sealing performance. The highest IP rating of the waterproof switch is IP68. The waterproof button switch has a reasonable design, long service life, high temperature resistance, and current shock resistance, which can meet your specific use needs.
Precautions
The specific application of these waterproof switches is restricted by many factors, such as the installation method and the installation direction of the product, the pressure difference of the airflow acting on the product, the strength of the fluid rebound and the working voltage. We also need to prevent the intrusion of corrosive gases or the intrusion of substances.
The waterproof metal switch cooperates with the circuit breaker to perform switch operations according to the needs of the system operation mode, and change the system operation wiring mode.