Patent ID: 8396603

Claim:
An irrigation controller, comprising: a plurality of control wires; an auxiliary ground wire; valve actuation control circuitry for generating a valve actuation control signal on at least a first control wire of the plurality of control wires for specifying a valve actuation period, wherein the valve actuation control signal comprising valve actuation period information for defining a first valve actuation period for a first of a plurality of valves electrically coupled between the first control wire and the auxiliary ground wire; a valve actuation selector for selecting one of the plurality of valves for actuating with the valve actuation control signal; wire tracker transmitter circuitry for transmitting a wire tracker signal on one the plurality of control wires, said wire tracker transmitter circuitry comprising: a signal transmitter for generating the wire tracker signal, wherein the wire tracker signal comprises an oscillating frequency; a wire tracker control wire selector for selecting one of the plurality of control wires for transmitting the wire tracker signal; a two-mode switch for, in a first mode, electrically coupling together a first pair of nodes and electrically coupling together a second pair of nodes, the first pair of nodes being electrically isolated from the second pair of nodes, and for electrically isolating from one another a third pair of nodes, and for, in a second mode, electrically isolating from one another the first pair of nodes and for electrically isolating from one another the second pair of nodes and for electrically coupling together the third pair of nodes, the two-mode switch further comprises: a first electrical connection between a first node of the first pair of nodes and the signal transmitter; a second electrical connection between a second node of the first pair of nodes and the wire tracker control wire selector; a third electrical connection between a first conductor in the second pair of nodes and the signal transmitter; a fourth electrical connection between a second node of the second pair of nodes and the auxiliary ground; a fifth electrical connection between a first node in the third pair of nodes and the valve actuation control circuitry; and a sixth electrical connection between a second conductor in the third pair of electrical conductors and the valve actuation selector.