A switch that is operated by rotation is known as a rotary switch. It consists of a rotating shaft that is connected to a terminal. That terminal is responsible for either setting up or breaking up a connection with other terminals. Rotary switches include diverse switch positions that can be established by pivoting the switch axle in different directions. Places where rotary switches can be used are band selectors present in multi-band radios or multi-speed fans and even on electrical metering equipment as range selectors. Till the early 1970s, these switches were also utilized on TV receivers as channel selectors

Generally, rotary switches find their use at places where there is a demand to operate an enormous number of electrical circuits covering a wide range of voltages, power, and current requirements. Presently they are used in applications as follows:

• Computers
• Instrumentation
• Aircraft equipment
• Communications equipment
• Medical equipment
• Industrial controls

A coded rotary selector switch or a coded rotary switch is very much like the normal rotary switch, however, the output is compiled in binary format to lessen pin requirement. It helps in selecting any one of the several choices.

Now let’s have a look upon the structure of this kind of switches.

A coded rotary switch comprises of "rotor" or a shaft that has a "spoke" or a contact arm that projects out from its surface like a cam. Around the rotor, there are several terminals in a circular arrangement. Each of them provides a contact for the shaft through which any distinctive electrical circuits can be associated. The switch is in a layered framework, thus, allowing the utilization of multiple poles. There is a detent component whose operation is initiated when the switch is moved from one position to another. Hence a coded rotary switch gives more prominent pole and throws abilities than simpler switches do. The detent mechanism, as well as the sensor/contact system, determines the total number of switching combinations that are possible.

The switches that are used presently work upon the principle of the "star wheel" mechanism to offer the switching position. Nylon cams are then mounted behind this component and spring-stacked electrical contacts slide around these cams. The cams are cut at locations where the contact should be closed, to sum up the electrical circuit. Some rotary switches are even client configurable in connection to the number of positions.

So this was all about regarding coded rotary switches. Hope you like this article. Brand that makes them are NKK Switches, Apem, and C&K. Make sure to check them out through their links.

View all the Coded Rotary Switches

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