Load-compensating weighing apparatus including signal modifying means

In a weighing apparatus of the return-to-zero load compensating type including a support (20);

• a weighing pan (10) normally having a given zero position relative to said support;
• means operable when the pan is displaced from the zero position by the application of a load thereto for returning the pan to its zero position, comprising pan sensing means (30) for generating a position signal (Ua) which is a function of the degree of displacement of the pan from its zero position, control signal generating means (32, 52) responsive to said position signal for generating a pan return signal (UR), and pan return means (14, 16) operable by said pan return signal for returning the pan to its zero position;
• and indicating means (36, 38) responsive to said pan return signal for providing an indication that is a function of the magnitude of the load applied to the pan;
• the improvement which comprises
• threshold circuit means including voltage-responsive impedance means having a severely curved voltage characteristic connected between said pan sensing means and said pan return means for modifying those pan position signals (Ua) having an amplitude less than a given amplitude, thereby to reduce the effect of external interference vibrations and accelerations on the control means and to increase the stability of the indication presented by said indicating means.