Switches and Buttons exist in many different forms. They both come in many different shapes and sizes and also function in many different ways. They are used in just as many ways in our electronics. Switches are a fundamental component we use every single day. They control the lights in our homes, allow us to engage with our appliances and tools, are the input for our videogames and computers, and more!
There are just as many types of switches as there are applications for switches. They can be built for whatever need is required. To the right are some common switches.
The most basic switch, a single-pole/single-throw (SPST), is two terminals with a half-connected line representing the actuator (the part that connects the terminals together).
Switches with more than one throw, like the SPDT and SPTT below, add more landing spots for the actuator.
Switches with multiple poles, usually have multiple, alike switches with a dotted line intersecting the middle actuator.
There are also switches that look like dials and have current flowing depending on which way the dial is moved. Those are called rotary switches.
Finally, there are some niche switches for niche applications like temperature shut-offs, temporary or limit switches that act more like a button, float switches that turn on when a water level gets high enough, and more!
Buttons are a little more basic. While they can come in just as many varieties as the switches do with just as many throws and poles, the basic button comes down to one of two features: Momentary or Permanent. A momentary button is a button that is only activated when pressed having a spring to bring it back to its original position. A permanent button, often just called a button, will have a clip that latches it into its activated position until pressed again. Their symbols are annotated to the left.
For more information on Buttons and a few experiments to build to further understand them, check out our page on Capacitors in a Circuit where we first seen buttons added to the circuits we will explore on MakerLessons.