Pulse telemetering apparatus for transmitting to a remote location the value of a magnitude

Claim 1

A TELEMETERING SYSTEM FOR TRANSMITTING THE MAGNITUDE OF A PHYSICAL QUANTITY COMPRISING IN COMBINATION: A TRANSMITTER COMPRISING TRANSDUCING MEANS FOR DERIVING FROM SAID QUANTITY A FIRST VOLTAGE PROPORTIONAL TO THE MAGNITUDE OF THE QUANTITY, INTEGRATOR MEANS COMPRISING A RESISTOR AND A CAPACITOR, SAID CAPACITOR BEING CONNECTED TO BE CHARGED BY SAID FIRST VOLTAGE THROUGH THE RESISTOR, MEANS FOR GENERATING A REFERENCE VOLTAGE, VOLTAGE COMPARATOR MEANS HAVING FIRST AND SECOND INPUTS, SAID FIRST INPUT BEING CONNECTED ACROSS SAID CAPACITOR TO RECEIVE THEREFROM A SECOND VOLTAGE PROPORTIONAL TO THE CHARGE ON SAID CAPACITOR, THE SECOND INPUT RECEIVING SAID REFERENCE VOLTAGE, AND AN OUTPUT DELIVERING AN ELECTRICAL SIGNAL EACH TIME SAID SECOND VOLTAGE BECOMES SUBSTANTIALLY EQUAL TO SAID REFERENCE VOLTAGE, MEANS CONNECTED TO SAID OUTPUT OF SAID VOLTAGE COMPARATOR FOR DISCHARGING SAID CAPACITOR IN RESPONSE TO SAID ELECTRICAL SIGNAL, WHEREBY A SUBSTANTIALLY SAW TOOTH VOLTAGE IS PRODUCED ACROSS SAID CAPACITOR HAVING A REPETITION RATE OF SUBSTANTIAL LINEAR RELATION TO SAID FIRST VOLTAGE, MEANS FOR GENERATING A CARRIER FREQUENCY AND FOR PRODUCING A MODULATED CARRIER WAVE HAVING A FREQUENCY PROPORTIONAL TO THE FREQUENCY OF THE SAW TOOTH VOLTAGE, MEANS FOR TRANSMITTING TO A DISTANCE THE MODULATED CARRIER SIGNAL, AND A RECEIVER COMPRISING MEANS FOR DERIVING FROM SAID MODULATED CARRIER SIGNAL A PULSE SIGNAL OF A REPETITION FREQUENCY EQUAL TO THAT OF SAID SAW TOOTH VOLTAGE, AND MEANS FOR MEASURING THE REPETITION FREQUENCY OF THE PULSES IN SAID PULSE SIGNAL, THE REPETITION FREQUENCY BEING LINEARLY RELATED TO SAID MAGNITUDE.