What is Pushbutton switch? Construction, Types, Advantages, Disadvantages

 

What is a Pushbutton switch? 

A pushbutton switch is an electrical switch that is activated by pressing a button or a momentary contact switch. It is a simple switch that is used to open or close an electrical circuit when the button is pressed or released, respectively. Pushbutton switches are commonly used in a variety of applications, including consumer electronics, industrial equipment, and automotive systems.

Components of a Pushbutton switch

The basic components of a pushbutton switch include:

1. Actuator: The actuator is the part of the switch that is pressed by the user to open or close the contacts. It can be a simple button or a more complex shape, depending on the design of the switch.
2. Contacts: The contacts are the electrical connections that open or close when the switch is activated. There are two types of contacts in a pushbutton switch: normally open (NO) and normally closed (NC). When the switch is activated, the NO contacts close and the NC contacts open.
3. Terminals: The terminals are the electrical connections that allow the switch to be connected to an electrical circuit. The terminals can be in the form of solder lugs, quick-connect terminals, or screw terminals, depending on the design of the switch.
4. Spring: The spring is used to provide the necessary force to return the actuator to its original position when the switch is released. The spring can be a separate component or integrated into the switch mechanism.
5. Housing: The housing is the outer casing of the switch that protects the internal components and provides a mounting surface for the switch. The housing can be made of plastic, metal, or other materials, depending on the intended use of the switch.
6. LED indicator: Some pushbutton switches have a built-in LED indicator that lights up when the switch is activated. This can be useful for indicating the status of the switch or providing feedback to the user.

Overall, pushbutton switches are relatively simple components that can be used in a wide range of electrical applications. They are available in many different sizes, shapes, and configurations to meet the needs of different types of devices and circuits.

Types of Pushbutton switches

There are two main types of pushbutton switches:

1. normally open (NO) and
2. normally closed (NC).

In a normally open switch, the contacts are open when the button is not pressed and close when the button is pressed.

In a normally closed switch, the contacts are closed when the button is not pressed and open when the button is pressed.

Here are some of the most common types of pushbutton switches:

1. Momentary pushbutton switch: A momentary pushbutton switch is a switch that only makes contact while the button is being pressed. When the button is released, the contacts open again. This type of switch is often used for temporary switching applications.
2. Latching pushbutton switch: A latching pushbutton switch is a switch that stays in the position it was last set until it is manually reset. This type of switch is often used for on/off switches or to set the state of a circuit.
3. Illuminated pushbutton switch: An illuminated pushbutton switch is a switch that has a built-in light source, such as an LED, that illuminates the button when the switch is activated. This type of switch is often used in low-light environments or to indicate the status of the switch.
4. Sealed pushbutton switch: A sealed pushbutton switch is a switch that is designed to be waterproof and dustproof. This type of switch is often used in outdoor or industrial applications where exposure to the elements is a concern.
5. Miniature pushbutton switch: A miniature pushbutton switch is a small switch that is designed for use in compact devices or tight spaces. This type of switch is often used in consumer electronics, such as mobile phones or handheld gaming devices.
6. Tactile pushbutton switch: A tactile pushbutton switch is a switch that provides a physical "click" or "snap" feedback when it is activated. This type of switch is often used in keyboards or other devices where a tactile response is desired.
7. Emergency stop pushbutton switch: An emergency stop pushbutton switch is a switch that is designed to immediately shut down a machine or device in an emergency situation. This type of switch is often used in industrial equipment or machinery.

Overall, the type of pushbutton switch that is best for a particular application will depend on the specific requirements and characteristics of the device or circuit.

Advantages and disadvantages of Pushbutton switches

Advantages of Pushbutton switch:

1. Easy to use: Pushbutton switches are very easy to use and require very little force to activate, making them ideal for applications where quick and frequent switching is required.
2. Versatility: Pushbutton switches are available in a wide variety of sizes, shapes, and configurations, making them highly versatile and suitable for use in a range of different applications.
3. Compact size: Pushbutton switches are relatively small and compact, making them ideal for use in devices where space is limited.
4. Durability: Many pushbutton switches are designed to be highly durable and long-lasting, with robust construction and materials that can withstand repeated use.
5. Customization: Pushbutton switches can be customized with different colors, markings, and LED lights to suit specific applications or user preferences.

Disadvantages of Pushbutton switch:

1. Limited switching capacity: Pushbutton switches are typically designed for low-current applications, and may not be suitable for high-power circuits or devices.
2. Limited functionality: Pushbutton switches are generally simple on/off switches, and may not be suitable for more complex applications that require multiple functions or settings.
3. Vulnerability to accidental activation: Because pushbutton switches can be activated with very little force, they may be more prone to accidental activation than other types of switches.
4. Limited tactile feedback: Some pushbutton switches may not provide a strong tactile feedback, which can make it difficult for users to know whether the switch has been activated or not.

Overall, pushbutton switches are highly versatile and easy to use, but may not be suitable for all types of applications. When choosing a pushbutton switch, it's important to consider the specific requirements of the application and select a switch that is capable of meeting those needs.