American Microsystems, Inc.

Bruce G Erickson

A visual tuning-aid system for aligning an electronic timepiece to a correct reference frequency is disclosed. A reference oscillator in the system provides a reference signal at a precisely fixed predetermined frequency which is, or is converted to, the correct alignment frequency for the timepiece. A sensor electrostatically detects a time base signal in the timepiece and a bandpass amplifier removes any extraneous signals. The reference signal and the time base signal are provided to a phase shift indicating device of a multiphase motor in the system which provides a visual display, the movement of which is proportional to the rate of phase change between the reference signal and the time base signal. Alignment of the timepiece to the correct frequency stops the phase change and thereupon the visual display stops moving.

Frequency tuning system with visual display

A visual tuning-aid system for aligning an electronic timepiece to a correct reference frequency is disclosed. A reference oscillator in the system provides a reference signal at a precisely fixed predetermined frequency which is, or is converted to, the correct alignment frequency for the timepiece. A sensor electrostatically detects a time base signal in the timepiece and a bandpass amplifier removes any extraneous signals. The reference signal and the time base signal are provided to a phase shift indicating device in the system which provides a visual display, the movement of which is proportional to the rate of phase change between the reference signal and the time base signal. Alignment of the timepiece to the correct frequency stops the phase change and thereupon the visual display stops moving.

Apparatus for ascertaining that the resonant frequency of a crystal frequency determining element lies within a predetermined frequency range is disclosed. A crystal whose frequency is to be measured is connected to an oscillator which provides vertical and horizontal deflection signals to a cathode ray tube device. Two crystal controlled signal generators provide series of short duration output impulses which are applied to the control grid of the cathode ray tube. One oscillator operates at the upper frequency limit of the frequency range, and the other oscillator operates at the lower frequency limit. If the crystal undergoing tests lies between the two frequencies of the two reference generators, two spots appearing on the screen of the cathode ray tube will rotate countercurrent with one another. If the frequency of the crystal undergoing test lies outside of the frequency range fixed by the two signal generators, those spots will rotate in the same direction, either clockwise or counterclockwise, depending upon whether the frequency of the crystal lies above or below the desired range.

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Santa Clara, CA, United States of America

Bruce G Erickson