Peak analysis and digital conversion apparatus

Claim 1

APPARATUS FOR ANALYSIS OF A VARIABLE SIGNAL VOLTAGE TO INDICATE THE OCCURRENCE OF PEAKS THEREIN COMPRISING FIRST MEANS OPERABLE TO COMPARE A PAIR OF INPUT SIGNALS AND TO SUPPLY ONE OUTPUT WHEN THE DIFFERENCE THEREBETWEEN IS GREATER IN THE POSITIVE SENSE THAN A FIRST PREDETERMINED LEVEL AND ANOTHER OUTPUT WHNE THE DIFFERENCE THERBETWEEN IS GREATER IN THE NEGATIVE SENSE THAN A SECOND PREDETERMINED LEVEL, SAID PREDETERMINED LEVELS DEFINING A DEADBAND CENTERED AT ABOUT ZERO DIFFERENCE, THE SIGNAL AND A REFERENCE SIGNAL FORMING THE TWO INPUT SIGNALS TO SAID FIRST MEANS, SECOND MEANS OPERABLE TO SUPLY SAID REFERENCE SIGNAL IN PERIODICALLY INCREASING LEVEL AS LONG AS SAID ONE OUTPUT IS AVAILABLE FROM SAID FIRST MEANS AND IN PERIODICALLY DECREASING LEVEL AS LONG AS SAID OTHER OUTPUT IS AVAILABLE FROM SAID FIRST MEANS, AND THIRD MEANS CONNECTED TO SAID FIRST MEANS AND OPERABLE ONLY WHEN SAID DIFFERENCE REMAINS IN SAID DEADBAND FOR AT LEAST A PREDETERMINED TIME PERIOD TO PROVIDE AN INDICATION OF A PEAK IN SAID SIGNAL VOLTAGE.