ARRANGEMENT TO MEASURE AND COMPENSATE FOR CRYSTAL ORIENTATION CHANGE

• US 3,600,951 A
• Filed: 03/12/1969
• Issued: 08/24/1971
• Est. Priority Date: 03/12/1969
• Status: Expired due to Term

• Current Assignee: Roger L. Easton
• Original Assignee: Roger L. Easton
• Inventors: Easton, Roger L.
• Primary Examiner(s): QUEISSER, Richard C.
• Assistant Examiner(s): Goldstein, Herbert
• Application Number:
  US04/806,640
• Time in Patent Office: 895 Days
• Field of Search: 73/382,517 33/204.3 331/56,162,166,175 310/8.4
• US Class Current: 73/382.00R
• CPC Class Codes: H03B 5/00 Generation of oscillations using amplifier with regenerative feedback from output to input H03B9/00, H03B15/00 take precedence

Abstract

Method and apparatus for symmetrically arranging two or more crystals so that changes of orientation can be measured but will not disturb the frequency of an ultrastable crystal oscillator.

Claims

1. A method of obtaining a very stable output from crystal oscillators comprising the steps of:

supporting in a symmetrical arrangement approximately matched crystals which control two or more oscillators in a manner such that the natural frequency shifts in the crystals caused by changing the gravitational orientation are compensatory and combining the outputs of said two or more oscillators, whereby the sum of said combined outputs is substantially independent of the gravitational orientation of said crystals.

2. The method of claim 1 including the further step of measuring the said natural frequency shifts in the crystals as an indication of said change of gravitational orientation.

3. A method of compensating for the change in frequency in a crystal oscillator caused by a change of orientation comprising the steps of:

supporting in a symmetrical arrangement approximately matched crystals in a plurality of crystal oscillators in such a manner that the sum of the natural frequencies of said crystals is substantially independent of the orientation of said crystals and combining the outputs of said plurality of crystal oscillators.

4. The method of claim 3 including the further step of measuring the difference in natural frequencies of two of said crystals as an indication of the magnitude of said change of orientation.

5. A combination stable crystal oscillator system and an orientation indicator for use on a vehicle comprising:

one or more pairs of crystals mounted in said vehicle, each pair of crystals being symmetrically supported and selected so that when one crystal rests on its support the other is suspended from its support and so that the sum of the natural frequencies of said pair of crystals is substantially independent of the orientation of said vehicle and each pair of crystals being arranged in a pattern that is orthogonal to the arrangement pattern of the others of said pairs of crystals;

a plurality of oscillators individually connected to and controlled by a crystal of said one or more pairs of crystals;

adding means connected to the outputs of said plurality of oscillators and functioning to combine said outputs and frequency difference measuring means connected to the outputs of the oscillators controlled by at least one of said pairs of crystals and functioning to measure the difference in the natural frequencies of said pair of crystals, whereby the output of said adding means is very stable and substantially independent of the orientation of said vehicle and the output of said frequency difference measuring means is a measure of the gravitational orientation of said vehicle.