Decimal number to log analogue conversion

Claim 1

APPARATUS FOR CONVERTING A DECIMAL NUMBER INTO AN APPROXIMATION OF THE COMMON LOGARITHM OF THE NUMBER COMPRISING: (A) A DECIMAL NUMBER-TO-BINARY CONVERTER HAVING BINARY OUTPUT TERMINALS CORRESPONDING TO 2*1 THROUGH 2*N RESPECTIVELY, FOR CONVERTING A VOLTAGE CORRESPONDING TO A DECIMAL NUMBER INTO BINARY FROM REPRESENTED BY A PULSE FROM ONE OF THE OUTPUT TERMINALS OR COINCIDENT PULSES FROM MORE THAN ONE OF THE OUTPUT TERMINALS, (B) N DIRECT VOLTAGE CIRCUITS EACH HAVING A BINARY INPUT TERMINAL, (A) EACH CIRCUIT BEING CONNECTED TO A RESPECTIVE BINARY OUTPUT TERMINAL OF SAID NUMBER-TO-BINARY CONVERTER, (B) EACH CIRCUIT HAVING A STABLE OPERATING STATE AND A TRANSITORY OPERATING STATE WHEN TRIGGERED BY AN INPUT PULSE FROM SAID DECIMAL NUMBER TO BINARY CONVERTER, (C) SAID CIRCUITS WHEN IN THE STABLE OPERATING STATE PROVIDING IDENTICAL OUTPUT REFERENCE VOLTAGES, (D) EACH CIRCUIT BEING IN THE TRANSITORY OPERATING STATE ONLY WHEN TRIGGERED BY AN OUTPUT PULSE FROM THE RESPECTIVE BINARY TERMINAL, (E) EACH CIRCUIT WHEN IN THE TRANSITORY OPERATING STATE PROVIDING A PREDETERMINED OUTPUT VOLTAGE DIFFERING FROM THE REFERENCE VOLTAGE BY AN INTEGRAL MULTIPLE OF ONE VOLT, THE INTEGRAL MULTIPLE CORRESPONDING TO THE BINARY EXPONENT OF THE TERMINAL TO WHICH THE RESPECTIVE CIRCUIT IS CONNECTED, (C) A LINEAR AMPLIFIER WHEREIN INPUT AND OUTPUT ARE IN THE RATIO OF LOG 10 2, (D) MEANS CONNECTED TO THE OUTPUTS OF SAID CIRCUITS TO PASS TO SAID LINEAR AMPLIFIER ONLY THE LARGEST OF COINCIDENT VOLTAGE DIFFERENTIALS FROM SAID CIRCUITS, (E) WHEREBY THE OUTPUT OF SAID DIFFERENTIAL AMPLIFIER IN VOLTS IS A ROUGH APPROXIMATION OF THE COMMON LONGARITHM OF THE NUMBER.