The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 31, 1981
Filed:
Dec. 19, 1977
Guy R Olbrechts, Bellevue, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
A modulator for controlling the frequency of the power applied to a gyroscope to rotate the seismic mass (wheel) of the gyro so as to compensate for movement of the gyro case about the spin axis of the gyro is disclosed. The modulator includes a slow acting phase-locked loop that includes: a high frequency (e.g., 20 MHz) crystal controlled voltage controlled oscillator (VCXO); a divider for dividing the VCXO frequency down by several decades (e.g., six decades); a phase comparator for comparing the relatively low frequency output of the divider with a low frequency reference signal; a loop filter for filtering the output of the phase comparator so as to give the loop its desired dynamic response characteristic and bandwidth; and, a summing amplifier for summing the output of the phase comparator with a rate signal having a voltage level linearly related to the rate of movement of the gyro case about its spin axis. The rate signal is obtained from a second gyro mounted so as to sense movement about the spin axis of the gyro whose power frequency is being modulated. The power frequency control signal is derived from the output of the VCXO via a divider, which may form part of the divider of the slow acting phase-locked loop.