Variable resistor without rotation angle limitation and having regular changes in resistance value

摘要

A variable resistor has a substrate, an insulating film, a resistance element, a rotary assembly and a wiper. The substrate has a first terminal having an annular segment, a second terminal and a third terminal having a semi-circular segment disposed adjacent to the annular segment of the first terminal. The insulating film has a central hole corresponding to the annular segment and covers the second terminal and the semi-circular segment. The resistance element is mounted on the insulating film and contacts the second terminal and the distal end of the semi-circular segment through two gaps of the insulating film. The rotary assembly is mounted on the substrate. The wiper is rotated by the rotary assembly and has multiple contacts respectively contacting the resistance element and the annular segment. Therefore, The rotary assembly can be continuously rotated to prevent accidental breakage without short-circuiting.