Patent
Self-compensating ovenized clock adapted for wellbore applications
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TLDR
In this paper, a temperature maintenance device and an oscillator crystal are disposed in a thermally insulated chamber and a processor is adapted to calculate a substantially constant frequency clock signal from the second output.Abstract:
A clock system is disclosed which includes a dual mode oscillator crystal having a first output having a frequency related to a temperature of the oscillator crystal and a second output having a frequency substantially stable with respect to temperature. The clock includes a temperature maintenance device. The temperature maintenance device and the oscillator crystal are disposed in a thermally insulated chamber. The clock includes a processor operatively coupled to the temperature maintenance device and the oscillator crystal. The processor is adapted to operate the temperature maintenance device so as to maintain a temperature of the chamber within a predetermined range. The processor is adapted to calculate a substantially constant frequency clock signal from the second output and a ratio of the frequency of the first output with respect to the frequency of the second output.read more
Citations
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Patent
Precision oscillator for an asynchronous transmission system
TL;DR: In this article, an integrated system on a chip with serial asynchronous communication capabilities includes processing circuitry for performing predefined digital processing functions on the chip and having an associated on-chip free running clock circuit for generating a temperature compensated clock.
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Downhole clock having temperature compensation
TL;DR: In this article, a downhole crystal-based clock that is substantially insensitive to the factors that may cause frequency deviation as a result of downhole temperature is presented, where the clock may include a plurality of crystals, where a first crystal may be more stable, with respect to temperature, than a second crystal.
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Apparatus and methods for acquiring seismic data while tripping
Otto N. Fanini,James C. Jackson +1 more
TL;DR: In this paper, a system for acquiring logging data comprises a controller for causing the generation of a signal in a formation surrounding a wellbore, and a receiver is deployed in the well-bore and is adapted for detecting the signal.
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Two way check shot and reverse VSP while drilling
TL;DR: In this article, the authors describe a system in which seismic energy is transmitted into the earth using a surface seismic source and then received with one or more surface receivers located on the surface of the earth.
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Method and apparatus for seismic data acquisition during drilling operations
TL;DR: In this article, an apparatus and a method for obtaining formation data while drilling is described, where a drill string and a plurality of sensors are provided, at least two of the sensors are spaced apart along the drill string a approximately the same distance as a length of a segment of the drill.
References
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Patent
Lower power oscillator with heated resonator (S), with dual mode or other temperature sensing, possibly with an insulative support structure disposed between the resonator (S) and a resonator enclosure
TL;DR: In this paper, a temperature sensing mechanism, control system and heating element comprise a temperature feedback control system which allows the crystal to stably operate at or very near its desired temperature.
Patent
Temperature compensated crystal oscillator
Takao Watanabe,Hayashi Mutsuo,Matsumoto Kazunari,Chikara Tsuchiya,Eiji Nishimori,Matsui Takashi +5 more
TL;DR: In this article, a data conversion circuit receives an analog temperature signal Vt from a temperature to voltage converter circuit, a digital compensation signal V1 from a memory and operation circuit and a voltage reference Vr from an auxiliary circuit.
Patent
Oven-heated crystal resonator and oscillator assembly
Abstract: A crystal resonator assembly is described wherein a piezo-electric resonator (14) is mounted over a heat conducting substrate (28) and one or more heat generating elements (40) are located on the substrate. The heating elements provide heat both by conduction and radiation and by virtue of the use of a heat conducting substrate enable a uniform and efficient heating of the crystal resonator to a desired oven temperature.
Patent
Temperature compensated crystal oscillator
TL;DR: In this article, a temperature compensated crystal oscillator with a temperature detecting circuit and a control signal generating circuit was presented. But the control signal was not applied to the operation temperature.
Patent
Quartz resonator cut to compensate for static and dynamic thermal transients
TL;DR: In this article, a method and apparatus utilizing a quartz crystal resonator with an orientation substantially equal to (yxwl) 21.93°/33.9° vibrating simultaneously in two thickness modes to accurately measure temperature and unknown frequencies or to provide a stable frequency signal source is described.