An appliance's control and sensing circuit selectively applies AC electrical power to a load (72). The circuit includes a relay (44) having contacts (52) connected in series between an AC power source and the load (72). When energized, the relay's electromagnetic coil (54) changes the contacts (52) to supplying electrical power to the load (72) or conversely. The control and sensing circuit measures AC voltage induced in the coil (54) by an alternating magnetic field produced by AC electrical current supplied to the load (72) through the relay's contacts (52). A microcontroller (46) included in the control and sensing circuit: 1. measures the AC voltage produced by the coil (54); 2. compensates the measured voltage for inductive coupling between the AC current flowing through the contacts (52) and the coil (54); and 3. determines various characteristics of the AC power supplied to the load (72).