Capacitively coupled sensor system for conveyor belts

A sensor system for a conveyor belt comprising a sensor stage on the conveyor belt and a stationary drive and detection stage external to the conveyor belt in the belt carryway. In an exemplary version, the sensor stage includes a capacitor sensor whose capacitance varies with the weight of a load atop a pressure platform at the belt's conveying surface. An oscillator in the drive and detection stage drives the capacitor sensor through capacitors formed when plates in the sensor stage in the advancing conveyor belt overlap stationary plates in the drive and detection stage during the belt's passage along the carryway. The corresponding plates in the belt and the carryway have different longitudinal dimensions to ensure constant plate overlap area of longer duration and despite lateral belt-tracking offset. The drive and detection stage detects the capacitance of the sensor and converts it into a weight value.