Capacity-type position sensor for electromagnetic load-compensation weighing apparatus

摘要

The position of the movable member relative to the stationary member of weighing apparatus of the electromagnetic load-compensation type is sensed by a variable-capacity alternating-current bridge network, use being made of two pairs of coplanar capacitive plate electrodes arranged in successively spaced opposed relation between planar parallel electrically-grounded surfaces of the movable and stationary members of the weighing apparatus. Opposed electrodes of each pair are connected in the bridge network to define two capacitive voltage dividers across the center points of which is developed an electrical signal corresponding with the deviation of the movable member from its zero position. The position sensor is manufactured in a simple manner and affords precise operation. All of the circuit connections are to fixed plate-type capacitive electrodes that may be mounted on a carrier member immediately adjacent the other electronic equipment.