Digital output transducer

Claim 1

A CIRCUIT FOR PROVIDING A DIGITAL INDICATION OF THE MAGNITUDE OF AN UNKNOWN FORCE COMPRISING MEANS FOR PRODUCING AN ELECTRICAL SIGNAL REPRESENTATIVE OF THE DIFFERENCE BETWEEN THE VALUE OF SAID UNKNOWN SOURCE AND A REFERENCE VALUE, A REVERSIBLE COUNTER, MEANS COUPLING SAID COUNTER TO THE OUTPUT OF SAID SIGNAL PRODUCING MEANS, SAID COUPLING MEANS INCLUDING MEANS FOR CAUSING SAID COUNTER TO ADD IF SAID ELECTRICAL SIGNAL IS GREATER THAN SAID REFERENEC VALUE AND SUBTRACT IF SAID ELECTRICAL SIGNAL IS LESS THAN SAID REFERENCE VALUE, A SOURCE OF PULSES, MEANS COUPLED TO SAID PULSE SOURCE AND OPERABLE IN RESPONSE TO SAID ELECTRICAL SIGNAL TO PASS PULSES TO BE COUNTED TO SAID COUNTERT, AN AMPLIFIER HAVING AN OUTPUT AND FIRST AND SECOND INPUTS, MEANS FOR DEVELOPING A FORCE IN OPPOSITION TO SAID UNKNOWN FORCE, A REFERENCE SOURCE COUPLED TO SAID FIRST INPUT OF SAID AMPLIFIER, FEEDBACK CIRCUIT MEANS COUPLING SAID FORCE DEVELOPING MEANS BETWEEN SAID OUTPUT AND SAID SECOND INPUT OF SAID AMPLIFIER, AND MEANS COUPLING SAID FEEDBACK CIRCUIT MEANS TO SAID COUNTER AND OPERABLE TO VARY THE SIGNAL FED BACK TO SAID SECOND INPUT BY SAID FEEDBACK CIRCUIT MEANS.