Patent ID: 7365453

Claim:
A control system comprising: a control module, the control module including: a first switch, the first switch providing a low impedance path between a control module output and a first voltage when the first switch is actuated, wherein the actuated first switch sinks current from the control module output; a second switch, the second switch providing a low impedance path between the control module output and a second voltage when the second switch is actuated, wherein the actuated second switch sources current to the module output; and a switch control circuit for controlling the first and second switches in accordance with a control module input, wherein the first switch is periodically actuated when the control module input is at a first state, the second switch is periodically actuated when the control module input is at a second state different from the first state, and neither switch is actuated when the control module input is at a third state wherein in the third state a high impedance is presented at the control module output, and no appreciable current is sourced or sunk through the control module.