Self-compensating encoder

Claim 1

AN ENCODER COMPRISING, IN COMBINATION, A SOURCE OF MESSAGE CURRENT; A SOURCE OF REFERENCE CURRENT; A SOURCE OF BIAS CURRENT; A SUMMING NODE; MEANS FOR CONVEYING ALL OF SAID CURRENTS TO SAID SUMMING NODE; MEANS FOR CONVERTING THE ALEGBRAIC SUM OF SAID CURRENTS INTO A TRAIN OF PULSES AND SPACES DESCRIPTIVE OF A PULSE CODE; SAID SOURCE OF REFERENCE CURRENT COMPRISING A WEIGHTED NETWORK THAT INCLUDES A PLURALITY OF SWITCHES BY WHICH SAID REFERENCE CURRENT TO SAID SUMMING NODE IS ALTERED, SAID SWITCHES HAVING A FINITE IMPEDANCE AND CONTACT POTENTIAL WHEN CLOSED AND DIVERTING PART OF SAID REFERENCE CURRENT TO GROUND WHEN IN THIS CONDITION; SAID SOURCE OF BIAS CURRENT COMPRISING A THIS CONDITION; SAID SOURCE OF BIAS CURRENT COMPRISING A ENCE CURRENT, AND A CURRENT GATE, RESPONSIVE TO SAID SWITCHING DEVICE, FOR CHANGING THE LEVEL OF SAID BIAS CURRENT INVERSELY AS THE LEVEL OF SAID REFERENCE CURRENT AT SAID SUMMING NODE IS AFFECTED BY THE COMBINED FINITE IMPEDANCE AND CONTACT POTENTIAL OF SAID SWITCHES WHEN THEY ARE ALL CLOSED.