Abstract: A digital weigh feeder includes a conveyor belt for transporting material thereon. The conveyor belt has an average tare weight. A digital weight transmitter provides at least first and second outputs having first and second frequencies respectively. The ratio of the first and second frequencies is indicative of the weight of material on the belt. A weight processor digitally computes a scaled ratio of the first and second frequencies. An auto tare circuit digitally computes the average tare weight of the conveyor belt. The computed average tare weight is substracted from the computed scaled ratio of the first and second frequencies to obtain a reading of the actual weight of material on the belt.

Abstract: Apparatus for generating a belt tare compensation signal including a load cell in operative contact with a feed conveyor belt dividable into N equal segments. The output of the load cell is strobed each time the conveyor belt advances one sampled and a pulse train representative of the output of the load cell is generated. The pulse train is applied to a pulse counter if the output of the load cell is greater than a predetermined value and is applied to a minus counter if the output of the load cell is less than a predetermined value. At the end of a single revolution of the conveyor belt, a signal representative of the difference between the count in the plus and minus counters is generated. This signal is divided by N so as to generate a belt tare compensation signal which is representative of the average output of the load cell during a single non-loaded revolution of the conveyor belt.