Variable resistor with a switch

摘要

A variable resistor with a switch which minimizes appearances of an arc and prevents incomplete contact between contacts of the switch originating from such an arc. The variable resistor with a switch includes a torsion coil spring having one end connected to a movable contact element supported for pivotal motion around a support shaft and the other end connected to a cam member also supported for pivotal motion around the support shaft. When the cam member is pivoted by movement of a slider receiver, a connecting point between the torsion coil spring and the cam member moves across a straight line interconnecting the support shaft and another connecting point between the torsion coil spring and the movable contact element so that a movable contact on the movable contact element is instantaneously brought into or out of contact with a fixed contact to turn the switch on or off irrespective of the speed of movement of the slider receiver.