Methods and apparatus for detecting ice readiness

Accurate sensing of ice readiness in an ice maker is accomplished using, as an ice readiness sensor, a capacitance bridge circuit having a first capacitor connected as a first bridge arm a second capacitor connected as a second bridge arm, a tunable capacitor connected as a third bridge arm and a probe connected as a fourth bridge arm. The probe includes a pair of electrode strips placed in close proximity to the belt of a belt ice maker. First and second bridge arms are connected at a first bridge node first and third bridge arms are connected at a second bridge node, second and fourth bridge arms are connected at a third bridge node, and third and fourth bridge arms are connected at a grounded fourth bridge node. The first and fourth bridge nodes are input terminals for receiving an AC drive signal from an AC source, and the second and third bridge nodes are output terminals. A signal processor, coupled to the second and third bridge nodes, includes an amplifier having its output coupled to a rectifier, and an output filter capacitor coupled to the rectifier. An output signal from the signal processor is supplied to a controller which controls the movement of the belt.