Weigh scale

In a weigh scale of the dual-beam type having large and small platform supports supporting high-flow and low-flow buckets respectively, a linear variable differential transformer to detect vertical movement of said platform supports, a ball screw with a movable poise weight operatively attached to one of said dual beams to keep said scale in balance while media is flowing into one of said buckets by movement of said poise weight, an encoder operatively attached to said ball screw to record the movement thereof, a poise motor to turn said ball screw, a pulse encoder, and a pulse encoder circuit to produce pulse train signals related to the movement of said ball screw, and a poise control circuit to accept signals from said pulse encoder circuit and said linear variable differential transformer to control the operation of said poise motor to keep said scale in balance as media enters said flow buckets, the improvement consisting of an improved poise control circuit including in combination circuitry providing low gain with high integration for use while said scale is running and, in addition, being adapted to provide a DC gain boost when said scale is being calibrated to provide for high gain and derivative action of said circuitry during calibration.