Electric circuits for generating an output voltage which is approximately proportional to a function of an input voltage

Claim 1

A FUNCTION GENERATOR COMPRISING AN INPUT TERMINAL TO WHICH AN INPUT VOLTAGE IS ARRANGED TO BE SUPPLIED, AN OUTPUT TERMINAL, AN ADDING CIRCUIT INCLUDING AN AMPLIFIER HAVING AN INPUT AND AN OUTPUT, A DIRECT CONNECTION BETWEEN THE OUTPUT OF SAID AMPLIFIER AND SAID OUTPUT TERMINAL, AND CIRCUIT MEANS INCLUDING A PATH CONNECTING SAID OUTPUT TERMINAL TO THE INPUT OF SAID AMPLIFIER, FIRST MEANS ARRANGED TO SUPPLY TO THE INPUT OF SAID AMPLIFIER IN DEPENDENCE UPON SAID INPUT VOLTAGE A FIRST CURRENT WHICH IS PROPORTIONAL TO THE FIRST TERM IN A CONVERGENT POWER SERIES, AND SECOND MEANS ARRANGED TO SUPPLY TO THE INPUT OF SAID AMPLIFIER IN DEPENDENCE UPON SAID INPUT VOLTAGE A SECOND CURRENT WHICH IS PROPORTIONAL TO THE SUM OF THE SECOND AND SUCCESSIVE TERMS IN SAID POWER SERIES, SAID SECOND MEANS INCLUDING A NON-LINEAR RESISTANCE HAVING AN INPUT AND AN OUTPUT AND HAVING A CURRENT/VOLTAGE CHARACTERISTIC SUBSTANTIALLY OF THE FORM I=KVA, WHERE I IS THE CURRENT FLOWING IN SAID NON-LINEAR RESISTANCE FOR A VOLTAGE V BETWEEN ITS INPUT AND OUTPUT, K IS A CONSTANT, AND A IS CONSTANT FOR A RANGE OF VALUES OF V, SAID ADDING CIRCUIT ADDING SAID FIRST AND SECOND CURRENTS AND SUPPLYING TO SAID OUTPUT TERMINAL AN OUTPUT VOLTAGE WHICH IS PROPORTIONAL TO THE REQUIRED FUNCTION OF SAID INPUT VOLTAGE.