Hunting and its Cure in a Precision Dynamometer Automatic Torque Mechanism

This thesis deals with the problem of eliminating hunting in the precision dynamometer torque mechanism of the Hydraulic-Machinery Laboratory of the Metropolitan Water District of Southern California at the California Institute of Technology, and its solution by apparatus built by and from plans proposed by the author. In addition to solving the particular problem here-in presented, the author, as part of his duties as a member of the laboratory staff, designed and built other apparatus for use in the laboratory. Some of these devices were built purely as experimental apparatus, while others were incorporated as permanent and necessary additions to the laboratory equipment. The following examples will serve as illustrations. The contacts of the automatic precision pressure gauges and venturi manometer required too frequent maintenance due to the delicacy of the instruments and the currents necessary for the contacts to control. A device using eight vacuum tubes solved this problem. It was desired to have a visual check of the laboratory “constant” frequency against a known standard radio station frequency. By utilizing a cathode ray tuning device such as the popular radio “Magic Eye”, an instrument was designed and constructed which showed deviations in frequency from zero cycles per second upwards. It is felt by the author that the following pages describing the elimination of dynamometer hunting show the manner in which he attacked and solved those problems presented to him.