Switches and Relays

Toggle Switch

To start off we will begin with the toggle switch. The toggle switch is used to make electricity choose between two different paths. Beyond that, there are a few types of toggle switches. The main one we will be focusing on is a SPDT, or single pull double throw. This is where a switch can be connected to one of two different points at one time. An example of this would be a light switch.


Other types of toggle switches can be determined by A) the amount of poles it has B) whether it is single or double throw and C) if it has an off center or not. So a Double Pull Double Throw switch would be read as DPDT.

Tactile Switch

The tactile switch works as a button. If you were to press the button down it would complete a circuit and allow current to pass through.



A relay is used to allow a magnetic field to control internal toggle switches to choose which path the electricity will flow to. In a DPDT relay, there are 8 contacts. 2 of these contacts are connected to a PSU and will form an electromagnetic field. That field will then move the internal toggle switch to connect to a different pole.



Now in schematics

here are some examples of what these switches would look like in schematics




The ability to choose which path to send electricity is key to understanding how to wire up certain circuits and in what order to do so. This key component is simple to understand but essential in performing even the most simple of functions, so it is best to think creatively about different ways they can be used.



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