Hi. Use NC limit switches. That means that there's normally a voltage present in the circuit and there's no action during that state. When the switch opens, the voltage goes to zero and the limit action is triggered. That's called an active-low switch.
NC switches are preferred because they fair better in electrically noisy environments. If you use NO switch a voltage spike caused by noise can trigger the limit switch action (which would be active-high for NO).
JR |