| 摘要 |
A variable resistor for use in a frequency regulator comprises an actuator having an intermediate portion pivotally supported by a casing, and a pair of opposite actuating end portions exposed from the casing. A pair of opposite feed pawls depend from the actuator to engage a rotor pivotally supported by the casing between the opposite feed pawls. The rotor has on peripheral edges thereof teeth meshing with the feed pawls, and carries a slider. A resistor base plate is mounted on the casing and has an arcuate resistor layer facing the slider of the rotor. The actuator is angularly movable in response to depression of one at a time of the actuating end portions thereof for turning the rotor in one direction through meshing engagement between the feed pawls and the teeth to thereby cause the slider to slide on the arcuate resistor layer. Therefore, the resistance of the variable resistor can be varied simply by pushing the actuator angularly back and forth. The variable resistor also includes a first light-emitting element for indicating operation of the variable resistor and a second light-emitting element for indicating an angular position of the rotor.
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