Term - Switch

From VEX Wiki

A switch is a mechanical device used to make or break connections within an electrical circuit. In robotics, switches can be used by the operator to give the robot commands. Switches can also be placed on the robot to respond to external triggers.

When a switch is triggered, it completes a circuit which sends a signal to the VEX Microcontroller. This signal can be interpreted by the programming in the Microcontroller to trigger some robot action.

The focus in this phase is on the VEX Bumper Switch and VEX Limit Switch and two momentary switches. A momentary switch is one that sends a signal only when it is triggered. When the trigger is removed, it springs back to its natural state and there is no signal.

A bumper switch is inside a plastic casing. As its name suggests, it is designed to act as a bumper. It can be exposed to impacts without risking damage to the switch itself. For this reason, it is useful in any application in which the trigger can be high impact.

A limit switch has a function similar to that of a bumper switch. Unlike the bumper switch, the limit switch has a thin sheet-metal arm as its trigger mechanism. This switch is not as durable as the bumper switch. In the event of a high impact, the metal arm will bend or break. However, this is also the biggest advantage of the limit switch. The metal arm is designed to be rebent into different shapes. By bending the arm, you can set up the limit switch to fit different applications.

A limit switch is most commonly used to determine when an arm has reached the limit of its travel (hence, the name limit switch). Typically, two limit switches are used, one at each end of the arm's travel. When the arm is all the way up, it hits the top limit switch, which signals the Microcontroller not to let the arm rise any farther. When the arm is all the way down, it hits the bottom limit switch, which signals the Microcontroller not to let the arm drop any farther.