Patent ID: 7746214

Claim:
A rotary variable resistor comprising: a support member; a variable resistor body having a front face mounted directly to a rear face of the support member; a bearing tube extending through a first aperture defined in the support member and away from a front face of the support member; a rotor shaft rotatably supported on the bearing tube and protruding away from the front face of the variable resistor body; a control knob coupled to an outer end of the rotor shaft, wherein the support member is disposed entirely between the variable resistor body and the control knob; a plate-shaped stopper extending through a second aperture defined in the support member and projectingly provided, along a rotational direction of the rotor shaft, on the front face of the variable resistor body from which the rotor shaft protrudes; and first and second restricting portions provided on the control knob in a side-by-side arrangement relative to each other and along the rotational direction of the rotor shaft, wherein the first and second restricting portions alternately abut against the stopper and define an actual rotational angle (β) of the rotor shaft.