Abstract: The switch of the invention is a double deck type rotary switch having a position deck for detecting a home position and means for determining each position of the switch relative to the home position. A switching deck, rotated together with the position deck, selectively applies operating voltage to a plurality of operative devices, such as sprinkling valves.The system incorporates a microprocessor to control a motor for driving the rotary switch to a commanded position. The position deck signals the microprocessor as the deck reaches the predetermined position and the processor provides a delay before applying voltage to the switching deck, insuring that good load contact is made, so that arcing is avoided. The switching deck makes its load contact a few degrees ahead of the position deck in order that the load contacts for the work voltage are in the center of their terminal spring clips before the microprocessor is signaled that the predetermined position has been attained.