Electrical balance

Claim 1

IN A FORCE MEASURING SYSTEM WHICH INCLUDES, MEANS DEFLECTABLE IN ONE DIRECTION FROM A REFERENCE POSITION IN RESPONSE TO A FORCE TO BE MEASURED, ELECTRICALLY ACTIVATED RESTRAINING MEANS COUPLED TO SAID DEFLECTABLE MEANS FOR URGING SAID DEFLECTIBLE MEANS IN THE OPPOSITE DIRECTION WHEN A VOLTAGE OF A PREDETERMINED POLARITY IS APPLIED THERETO, THE COMBINATION OF: A POSITION TRANSDUCER FOR SENSING THE POSITION OF SAID DEFLECTABLE MEANS FOR PRODUCING AN ELECTRIC SIGNAL HAVING CHARACTERISTIC VARIATIONS CORRESPONDING TO CHANGES IN THE POSITION OF SAID BALANCE BEAM, ELECTRIC CIRCUIT MEANS COUPLED TO SAID POSITION TRANSDUCER AND RESPONSIVE TO SAID ELECTRIC SIGNAL TO PRODUCE A VOLTAGE ACROSS ITS OUTPUT A CHANGE IN VOLTAGE APPEARING ACROSS SAID OUTPUT BEING PROPORTIONAL TO A CHANGE IN THE MAGNITUDE OF SAID FORCE, MEANS CONTROLLED BY SAID ELECTRIC CIRCUIT MEANS FOR APPLYING VOLTAGE TO SAID RESTRAINING MEANS TO MAINTAIN SAID DEFLECTABLE MEANS SUBSTANTIALLY IN SAID REFERENCE POSITION, AND A VOLTAGE-MEASURING CIRCUIT COUPLED TO SAID ELECTRIC CIRCUIT MEANS FOR MEASURING CHANGES IN VOLTAGE APPEARING IN THE OUTPUT THEREOF, SAID VOLTAGE MEASURING CIRCUIT COMPRISING A ZERO-SUPPRESSION VOLTAGE SOURCE AND MEANS FOR MEASURING THE DIFFERENCE BETWEEN THE VOLTAGE SUPPLIED BY SAID SOURCE AND THE VOLTAGE PRODUCED BY SAID ELECTRIC CIRCUIT MEANS, SAID VOLTAGE SOURCE COMPRISING A POTENTIOMETER AND A VOLTAGE SUPPLY CONNECTED THEREACROSS, SAID MEASURING MEANS COMPRISING A RESISTOR CONNECTED IN SERIES WITH AN ADJUSTABLE PART OF SAID POTENTIOMETER ACROSS THE OUTPUT OF SAID ELECTRIC CIRCUIT MEANS, AND A VOLTAGE MEASURING DEVICE HAVING A PREDETERMINED RANGE CONNECTED ACROSS SAID ELECTRIC CIRCUIT MEANS AND HAVING A RANGE LESS THAN THE VOLTAGE PRODUCED ACROSS SAID ELECTRIC CIRCUIT MEANS.