Function generator using linear elements

Claim 1

APPARATUS FOR PRODUCING A SIGNAL REPRESENTING A NONLINEAR FUNCTION OF A VARIABLE THAT CONTINUALLY CHANGES SLOPE ONLY IN ONE DIRECTION COMPRISING FIRST MEANS ADAPTED TO PRODUCE A FIRST SIGNAL THAT VARIES AS A LINEAR FUNCTION OF SAID VARIABLE AT A RATE THAT IS NEVER GREATER AND NEVER LESS RESPECTIVELY THAN THE MINIMUM AND MAXIMUM RATES AT WHICH SAID NONLINEAR FUNCTION VARIES WITH RESPECT TO SAID VARIABLE WHEN THE SLOPE OF SAID NONLINEAR FUNCTION RESPECTIVELY CONTINUALLY INCREASES AND CONTINUALLY DECREASES, SECOND MEANS FOR MULTIPLYING TWO SIGNALS TO PRODUCE A PRODUCT OUTPUT SIGNAL, MODIFYING MEANS RESPONSIVE TO SAID PRODUCT SIGNAL TO INCREASE AND DECREASE THE MAGNITUDE OF SAID LINEAR FUNCTION SIGNAL IN PROPORTION TO THE INSTANTEOUS MAGNITUDE OF SAID PRODUCT SIGNAL WHEN RESPECTIVELY THE SLOPE OF SAID NONLINEAR FUNCTION SIGNAL CONTINUALLY INCREASES AND CONTINUALLY DECREASES, AND THIRD MEANS RESPONSIVE ACCORDING TO THE MAGNITUDE OF SAID FIRST SIGNAL TO PRODUCE A MULTIPLIER SIGNAL THE INSTANTANEOUS MAGNITUDE OF WHICH IS SUCH THAT THE PRODUCT OF THE SIGNAL FROM SAID MODIFYING MEANS AND SAID MULTIPLIER SIGNAL VARIES LIKE A NONLINEAR FUNCTION OF SAID VARIABLE, SAID MULTIPLIER SIGNAL AND THE SIGNAL FROM SAID MODIFYING MEANS BEING THE TWO SIGNALS APPLIED TO SAID MULTIPLYING MEANS.