Keyswitches are at the heart of one of the most used human input devices, the keyboard. They are produced in a number of different form factors and styles. When the keycap is depressed the keyswitch presses into a pcb located below it, which in turn completes a circuit sending an electrical impulse to the device resulting in the predetermined action.
Description
Keyswitches are at the heart of one of the most used human input devices, the keyboard. They are produced in a number of different form factors and styles. When the keycap is depressed the keyswitch presses into a pcb located below it, which in turn completes a circuit sending an electrical impulse to the device resulting in the predetermined action. These keyswitches preform the same type of action that a momentary, non-latching, switch preforms. The basic action is a temporary state change.
Data sheets
Link to folder containing all the datasheets for the given keyswitches
Basic information of from the datasheet
- Switching Voltage 12V AC/DC max – 2V AC/DC min
- Switching Current 10mA AC/DC max – 10µA min
- Insulation Resistance 100MΩ/DC 500V
- Withstand Voltage 100V AC 1 minute
- Dielectric Strength 500V 50Hz
- Actuation Force 45cN-95cN
Example Uses
The keyswitch is first and foremost design to use in keyboards. Most have a fast response time and because of the pcb and firmware used often times multiple keypresses from different keys at the same time still register. although these keyswitches are predominantly found in keyboards the possibilities for use in other areas is quite broad. There are some mice on the market that use these type of switches for under the two main left and right buttons. Furthermore there are many different types of keyswitches in terms of feel, clicky, quiet, tactile, and are also available with different actuation force.
Strengths and Weaknesses
The major weakness of all keyswitches on the market today is the need for a specific pbc ,layout and the need for a specific housing. The size of most keyswitches has been somewhat standardized over the past few years however, the pcb layout and interface have not.
Example Circuit Schematic
Example diagram of Cherry MX Red switch
linear actuation no sound.
Example diagram, Cherry MX Blue
Tactile and Audible
Example Microcontroller Code
One way to use a keyswitch is as a momentary switch, thusly an code that would take advantage of a momentary switch for a state change will work. {INSERT CODE HERE). The other way is to use it with this code(INSERT CODE HERE) and a keyboard library or firmware like QMK.
