Regulator

Claim 1

IN A SYSTEM FOR REGULATING THE SPEED OF A ROTARY DEVICE: A SIGNAL-GENERATING TACHOMETER HAVING A SELECTIVE PLURALITY OF OUTPUTS, EACH CORRESPONDING TO A DIFFERENT ROTARY SPEED RANGE AND EACH BEING A DIFFERENT MULTIPLE OF THE INPUT FROM THE ROTARY DEVICE, SAID TACHOMETER BEING COUPLED TO THE DEVICE FOR ROTATION THEREWITH; A FIXED FREQUENCY REFERENCE SIGNAL SOURCE; A MIXING CIRCUIT FOR COMBINING THE SIGNALS FROM SAID TACHOMETER AND SAID SOURCE TO PRODUCE A SIGNAL HAVING A FREQUENCY EQUAL TO THE ACTUAL DIFFERENCE BETWEEN THE SELECTED TACHOMETER AND SOURCE SIGNALS; A RESONANT DISCRIMINATOR CIRCUIT COUPLED TO THE MIXING CIRCUIT, SAID DISCRIMINATOR CIRCUIT INCLUDING COMPONENTS TUNABLE TO A FREQUENCY EQUAL TO A PRESELECTED DIFFERENCE BETWEEN THE FREQUENCIES OF THE TACHOMETER AND SOURCE SIGNALS; AND SPEED CORRECTION MEANS INTERCONNECTING THE DISCRIMINATOR CIRCUIT AND SAID DEVICE, SAID DISCRIMINATOR CIRCUIT HAVING AN OUTPUT ONLY WHEN THE ACTUAL DIFFERENCE VARIES FROM THE RESONANT FREQUENCY.