Rotary test table rate smoother

Claim 1

APPARATUS FOR MAINTAINING THE ANGULAR VELOCITY OF A SLOWLY ROTATING BODY DRIVEN BY A SYNCHRONOUS MOTOR AT A SUBSTANTIALLY CONSTANT VALUE, SAID APPARATUS COMPRISING: AN ANGULAR POSITION MONITOR COUPLED TO SAID BODY FOR PRODUCING AN ELECTRICAL PULSE AFTER EACH 360/N DEGREES OF ROTATION OF SAID BODY, WHERE N IS AN INTEGER; A STABLE OSCILLATOR HAVING A FREQUENCY D1D2N/P, WHERE D1 AND D2 ARE INTEGERS AND P IS THE ROTATIONAL PERIOD OF SAID BODY; MEANS FOR DIVIDING THE FREQUENCY OF SAID OSCILLATOR BY D1 AND FOR APPLYING THE RESULTING FREQUENCY TO A FREQUENCY CHANGER HAVING TWO POSSIBLE STATES IN ONE OF WHICH IT INCREASES THE APPLIED FREQUENCY BY A SMALL PREDETERMINED AMOUNT AND IN THE OTHER OF WHICH IT DECREASES THE APPLIED FREQUENCY BY SAID PREDETERMINED AMOUNT; MEANS COUPLED TO THE OUTPUT OF THE SAID CHANGER AND TO SAID MOTOR FOR ENERGIZING SAID MOTOR AT THE CHANGER OUTPUT FREQUENCY; MEANS FOR DIVIDING THE FREQUENCY APPLIED TO SAID CHANGER BY D2 TO PRODUCE A REFERENCE WAVE; AND MEANS FOR COMPARING THE PHASE OF THE PULSE WAVE PRODUCED BY SAID MONITOR WITH THE PHASE OF SAID REFERENCE WAVE AND OPERATING WHEN SAID MONITOR PULSE WAVE LAGS SAID REFERENCE PULSE WAVE TO PLACE SAID FREQUENCY CHANGER IN ITS FREQUENCY INCREASING STATE AND OPERATING WHEN SAID MONITOR PULSE WAVE LEADS SAID REFERENCE WAVE TO PLACE SAID FREQUENCY CHANGER IN ITS FREQUENCY DECREASING STATE.