A single pole, double throw, self-canceling rotary switch for selectively coupling a first circuit to a second or a third circuit by rotating a rotary element to couple or decouple electrical contacts. The rotary switch includes first and second pawls pivotally attached to the rotary element and coupled to one another by a spring. Rotation of the rotary element causes a ramp cam to act on one of the pawls, causing it to pivot, and thereby causing the spring to exert a force on the other pawl, moving a tooth on the other pawl into the locus of rotation of a central shaft that includes a groove. Rotation of the central shaft in one direction has no effect on the position of the rotary element, but rotation of the central shaft in the other direction engages the groove and the tooth, causing the rotary element to decouple the contacts.