A Free Quartz Pendulum: Electrostatically Driven and Photoelectrically Controlled as a Means of Precision Timekeeping

Citation

Atwood, Albert William, Jr. (1933) A Free Quartz Pendulum: Electrostatically Driven and Photoelectrically Controlled as a Means of Precision Timekeeping. Master's thesis, California Institute of Technology. doi:10.7907/c5s0-qx08. https://resolver.caltech.edu/CaltechTHESIS:10272024-015633448

Abstract

After making a careful study of the field of timekeeping the pendulum was found to be the best timekeeper. A lengthy investigation was made of all the factors that affect the period of a pendulum, and these are outlined in the report. Choosing a free pendulum in preference to the compensated compound pendulum, the period of one half second was taken, and the physical dimensions of a pendulum worked out. It was decided to make the pendulum entirely of quartz, and to operate it in a vacuum. An original electrostatic drive was adopted as the means of keeping the pendulum in motion. This drive required the design of a special circuit which has been worked out, and the constants of this circuit calculated with an assumed damping factor.

Construction was started, but much difficulty was encountered, especially in the making and fastening of a fine quartz spring to the rod. A strong mounting and the driving condenser have also been built. A good bibliography has been worked up for t he aid of the person who carries on this work.

Thesis Files