We’re used to thinking of limit switches as a mechanical device that cuts the motor connection before physical damage can occur. [Anthony] decided to try a different route with this project.

This is not a fail-safe arrangement as the scheme will not work if a switch wire breaks or disconnects ... impedance of any transients that are heading towards the board. The limit switch pairs go in ...

Understanding how these components work together is key to understanding ... little physical force used in safety interlocks and limit switches ...