3 terminals, applicable to AC control circuits.Designed to control the movement of a mechanical part.Typically utilized in industrial control applications to automatically monitor and indicate whether the travel limits of a particular device have been exceeded.High precision mechanism design offering acute operation and long life.In snap action contacts, the movement of the actuator applies force to an overcenter mechanism.This mechanism creates a quick change in contact state when the trip point is reached.Reversing the motion of the actuator to a given reset point causes the contacts to snap back to their original position.Snap action contacts have different trip and reset points.The distance between the trip and reset point is called the travel to reset, hysteresis, or differential.Finite travel to reset helps to avoid multiple changes of state if the object actuating the switch is subject to vibration.Snap action contacts ensure repeatable performance in applications that involve low speed actuators.The amount of travel of the contacts is also not dependent on the amount of travel by the actuator.