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

A variable resistor comprising:

• a casing having an open end
• a substrate being mounted on the open end of the casing and having
• a front surface;
• a rear surface;
• a through hole;
• and
• a terminal group being conductive and formed on the front surface of the substrate and having
• a first terminal having an annular segment surrounding the through hole and a connector extending from the annular segment;
• a second terminal being separated from the first terminal and having a connector adjacent to the connector of the first terminal;
• and
• a third terminal being separated from the first terminal and the second terminal and having
• a semi-circular segment being disposed adjacent to the annular segment of the first terminal and having a proximal end and distal end;
• and
• a connector extending from the proximal end of the semi-circular segment adjacent to the terminal of the second terminal;
• an insulating film being annular, covering the second terminal and the semi-circular segment of the third terminal, surrounding the annular segment and having
• a central hole corresponding to the annular segment of the first terminal;
• and
• two gaps respectively corresponding to the second terminal and the distal end of the semi-circular segment of the third terminal;
• a resistance element being annular, being mounted correspondingly on the insulating film and respectively contacting the second terminal and the distal end of the semi-circular segment of the third terminal through the gaps of the insulating film;
• a rotary assembly being mounted on the substrate and attached to the casing;
• and
• a wiper being attached to and rotated by the rotary assembly and having multiple first contacts contacting the resistance element;
• and
• multiple second contacts contacting the annular segment of the first terminal of the terminal group.