A tactile switch offers the passage of electricity in an electrical circuit whenever the operation section is pressed by the user. The switch serves as a supplier of input signals such that the device gets operated. It is structured with a small impression appropriate for mounting onto the surface area of PCB (Printed Circuit Sheets) made to associate electronic segments to shape electronic circuits.
Whenever pressed the switch gets activated and gets turned off when released. This action is termed as ‘momentary action' which can only be executed at low current and low voltage. There is a wide range of tactile switches available in the market. They are also popular with the name of tact switch or tactile push switch. They have found their use in several areas like industrial machinery, household appliances, commercial equipment, and office equipment. A user can choose any kind of tactile switches for their equipment based on board mounting, size (external dimension) and sealing structure.
Structure
A typical tactile switch has four of the most important things. They are discussed below:
- Cover: The cover defends the switch’s internal parts. The covers are generally made up of metals and are attached to the base. For static electricity protection, some covers also come with a ground terminal.
- Plunger: Basically the plunger is a button that is pressed by the user to activate the switch. It transfers the squeezed force to the contact dome. The arrangement of the plunger surface can be either projected or flat. Generally, plungers are constructed using molded resin but to offer long strokes some come with rubber materials.
- Contact Dome: The contact dome gives a feeling of click and also behaves like a movable contact. When a certain amount of operating force is provided to the plunger the contact dome reverses its shape and connects the 2 fixed circuits electrically to power the circuit. After the removal of this operating force, the dome returns to its original shape. The contact dome that is made up of rubber provides a softer tactile response by increasing the operation stroke. On the other hand, the metal dome provides a sharper tactile response by decreasing the operation stroke.
- Base: The base of the switch is made using molded resin. Resin materials are only used because they can withstand the heat of soldering.
Features
- Click Response: One of the most characteristics features of tact switches is the click response of the button i.e. it gives the individual a chance to feel the reaction from the switch. A feeling of clicking is initiated from the contact dome inside the tact switch. The shape and the material of the contact dome determine the sharpness of the click sense.
- High Durability: The contact dome also serves as a movable contact in tact switches. The contact resistance (resistance value) is formed between fixed contacts and movable contacts whenever the switch is ON. It can be stabled down by utilizing specific materials, shape which provides high durability that is capable of holding a hundred thousand to ten million times of use and surface processing.
This was a brief article regarding tactile switches. Hope you liked reading it. Brands that make it are C&K, Panasonic and E-Switch. Make sure to check them out using their links.
View all the Tactile Switches