A kind of small current master switch is a kind of travel switch and position switch. Using the collision of the moving parts of the production machinery, the contact action can be achieved to connect or break the control circuit, so as to achieve certain control purposes. Usually, this type of switch is used to limit the position or stroke of mechanical motion, so that the motion machinery is automatically stopped in a certain position or stroke, reverse motion, variable speed motion, or auto round and round motion.

In electrical control system, the role of position switch is to realize sequential control, location control and position detection. It is used to control the travel and limit protection of mechanical equipment. Structure: it consists of operation head, contact system and shell. In actual production, the stroke switch is installed in the pre arranged position. When the module is installed on the moving parts of the machine, the contact action of the stroke switch is carried out to realize the switch of the circuit. Therefore, the stroke switch is a kind of electrical apparatus that switches the circuit according to the travel position of the moving parts. Its working principle is similar to that of the button.

The trip switch is widely used in all kinds of machine tools and hoisting machinery to control its journey and terminal limit protection. In the elevator control circuit, we also use the travel switch to control the speed of the car door, the limit of the automatic switch door and the upper and lower limit protection of the car. A stroke switch can be installed on a relatively stationary object (such as a fixed frame, a door frame, etc., for short) or on a moving object (such as a driving, door, etc.). When the animal approaches the still object, the contact of the connecting rod driving switch of the switch causes the closed contact point or the broken contact closure. The operation of the circuit and mechanism is controlled by the change of the opening and closing state of the switch contacts