Abstract: A crystal oscillator in which IC control terminal electrodes for writing temperature compensation data in an IC chip are formed on side surfaces of a main body while being distanced from the top and bottom surfaces of the main body. The IC control terminal electrodes will not be short-circuited with a conductive pattern for sealing the crystal oscillating element on the top surface, and the IC chip will not be destroyed by a welding current which flows when a metal cover is mounted on the top surface. The IC control terminal electrodes will not be short-circuited with other wiring conductors during the soldering to bond the crystal oscillator to a printed circuit board. The compensation data or other data written in the IC chip can be stably maintained, thereby securing a stable operation.

Abstract: The frequency of a quartz oscillator having a trimmer 2, a quartz oscillator 3 on which its temperature characteristic is printed in the form of a bar code 6, and a storage device 4 is adjusted to a predetermined frequency, and the temperature at that time is measured by a noncontact temperature sensor of a frequency adjusting device 10, and is written into the storage device 4. The temperature characteristic of the quartz oscillator is read by a bar code reader 21, and optimally suited temperature compensating data is selected from among a plurality of pieces of temperature compensating data stored in advance in a temperature-compensating-data writing device. Further, a frequency deviation between the temperature at the time of adjustment and a standard temperature is calculated, and the temperature compensating data including that frequency deviation is stored in the storage device 4.

Abstract: An ultrasonic sensor has a built-in temperature compensation capacitor housed in a casing and facilitates an inside-the-casing lead-wire bonding connection process and a connection verifying process while increasing reliability. The ultrasonic sensor is provided with a piezoelectric vibration element and a capacitor for temperature compensation capacitor both housed in a casing. The temperature compensation capacitor includes a pair of electrodes located on one common surface of a dielectric body thus allowing the ultrasonic sensor to be electrically connected to lead wires on the one common surface.

Abstract: A digital temperature compensation oscillator by which its AFC operation to a receive signal cannot be disturbed by temperature compensation operation. A digital temperature compensation oscillator comprises a temperature sensor, an address creating section, a ROM, latching means, and a voltage-controlled crystal oscillator. The temperature sensor produces an output signal varied according to ambient temperatures. The address creating section converts an output from the temperature sensor into a signal and then creating it as a ROM (read-only memory) address. The ROM stores a control voltage to compensate a frequency variation due to ambient temperatures of a voltage-controlled crystal oscillator. The latching means holds or passes data output from the ROM according to an external control signal. The D/A converter produces a control voltage for the voltage-controlled crystal oscillator according to the latching means.

Abstract: A crystal oscillator and method for manufacturing same including excitation electrode portions formed upon a crystal substrate and thus forming an excitation portion of the area defined between the electrode portions. Axis inversion portions possess an electrical axis (-X) opposite to the electrical axis (X) of the excitation portion, these axis inversion portions being formed within the crystal substrate at a position other than that of the excitation portion. A stable resonance frequency and filter frequency can be obtained even under conditions of ambient temperature fluctuation, by means of a relatively simple temperature compensation circuit, wherein handling is easy and no complicated adjustment is necessary, and low costs can be realized.

Abstract: A resonant circuit of the present invention has a ceramic substrate, a quartz element provided on said substrate, and a capacitor for temperature compensation. Connection terminals are formed on the rear of the substrate in order to mount the resonant circuit to another substrate. A seam ring for air-tight sealing is positioned at the edges of the substrate. The quartz oscillator with this configuration can be mounted without resorting to leads.

Abstract: A piezoelectric resonator includes a base member having a piezoelectric member at the center and dielectric members disposed at opposite ends. A plurality of internal electrodes are provided in the base member. The piezoelectric member layer at the center of the base member is polarized in the longitudinal direction of the base member in opposite directions at both sides of each internal electrode. The center section of the base member is used as a vibrating section. On the other hand, the dielectric members at both ends of the base member are not polarized and are used as capacitor sections. Adjacent internal electrodes are connected to external electrodes serving as input and output electrodes, respectively.

Abstract: 36.degree. -rotated Y-cut X-propagation lithium niobate substrate (LiNbO.sub.3) was used as a piezoelectric substrate to compose a surface acoustic wave filter and is connected with a dielectric filter in series. The dielectric filter having a sign of the frequency temperature characteristic which is opposite to that of the surface acoustic wave filter was used. Accordingly, a high frequency filter, comprising a surface acoustic filter and a dielectric filter connected in series, which can secure sufficient attenuation without an increase in the insertion loss within the band can be provided.

Abstract: A vibration detecting sensor includes a vibrating plate, a vibration detecting piezo-electric element attached to the upper surface of the vibrating plate, a temperature compensating piezo-electric element attached to the upper surface of a second plate, covering members for covering the respective plates, and lead-in wires connected electrically to the respective piezo-electric elements.

Abstract: A vibration gyroscope having stable sensitivity characteristic against temperature change has an amplifier circuit which amplifies a detection signal derived from a piezoelectric vibrator. The amplifier circuit includes an input terminal, an operational amplifier having a non-inversion input connected to the input terminal and an inversion input which is grounded, an output terminal connected to the output of the operation amplifier, a first temperature-sensitive element connected between the non-inversion input of the operation amplifier and the ground, and a second temperature-sensitive element connected between the inversion input of the operational amplifier and the output of the same.

Abstract: A vibrating gyroscope includes a vibrator having a triangular prism shaped vibrating body and piezoelectric elements. An oscillation circuit is connected between two piezoelectric elements and another piezoelectric element. Output signals from two piezoelectric elements are applied to input terminals of a differential circuit. The differential circuit is connected to a synchronous detecting circuit, and the synchronous detecting circuit is connected to a smoothing circuit. A temperature compensating capacitor is connected between two piezoelectric elements that are connected to the differential circuit. The oscillation circuit consists of an amplifier and a phase shifter having a resistor and a capacitor. As the capacitor used in the phase shifter, the temperature compensating capacitor may be used.

Abstract: A vibration-type angular velocity detector is for accurately correcting temperature-induced variations of an angular velocity signal without using a temperature sensor. A driving piezoelectric element, a detecting piezoelectric element and reference piezoelectric element are disposed on a vibration element. Using an output signal of the reference piezoelectric signal, a feedback control loop for applying driving voltage to the driving piezoelectric element is provided using an amplifier, a phase-shifting circuit, a rectifier, a reference voltage generator, a differential amplifier and a multiplier so as to vibrate the vibration element at a fixed amplitude. In addition, using an output signal of the detecting piezoelectric element at the time of vibrating the vibration element, an angular velocity signal is output. Here, the output voltage of the differential amplifier is a signal corresponding to the temperature of the vibration element.

Abstract: An ultrasonic aerosol apparatus having a piezoelectric element which generates ultrasonic signals in response to signals received from an oscillating circuit, where the temperature of the piezoelectric element is controlled by an electronic device such as an N.T.C. thermistor. The temperature control device senses the temperature of the piezoelectric element and controls the power fed to the oscillator circuit in accordance with the temperature of the piezoelectric element. Rather than cut power completely to the oscillator circuit (thereby interrupting the atomization process of the apparatus), the temperature control device reduces power fed to the oscillator circuit when the piezoelectric element temperature rises above a predetermined value, and increases power fed to the oscillator circuit when the piezoelectric element temperature falls below a predetermined value. Leakage of liquids (e.g.

Abstract: A method for controlling a piezoelectric actuator includes: a safety range setting process in which a safety range V.sub.range1 or V.sub.range2 of an applied voltage is set so that an area of 180.degree. domain rotation is within one third or less of an area of full 180.degree. domain rotation S.sub.1 or S.sub.2 in a positive or negative region of the applied voltage; and a driving process in which the voltage is applied to the piezoelectric actuator with a limitation of the safety range V.sub.range1 or V.sub.range2. A controller which drives a piezoelectric actuator according to the controlling method is also provided. A temperature compensation is applied if necessary. The 180.degree. domain rotation is limited by the lower or upper limit of the safety range, so that local concentration of inner stress is suppressed and the actuator is driven at its maximum ability without cracks or splits.

Abstract: In a portable telephone which uses a CPU, a memory, a temperature sensor, a D/A converter, and an A/d converter as control elements, and which has an oscillation circuit including a crystal resonator and a variable-capacitance diode, temperature compensation of the output frequency is made by using these existing control elements. The memory is previously stored with control information for correcting an output frequency drift of the portable telephone caused by a temperature change. The temperature of the oscillation circuit is detected with the temperature sensor and converted into a digital value in the A/D converter. The CPU reads control information corresponding to the detected temperature from the memory and applies it to the variable-capacitance diode of the oscillation circuit through the D/A converter, thereby maintaining the output frequency at a constant level.

Abstract: An oven assembly for a crystal resonator and oscillator utilizes a thermally symmetrical design to provide a high thermal gain. The oven assembly includes an encasement that forms a hermetically sealed oven chamber that is substantially cylindrical. Concentric with the oven chamber is an annular oven mass that functions as a heat reservoir for the crystal resonator that is contained within the oven mass. The cylindrical oven chamber and the concentric annular oven mass provide two levels of circular symmetry that help achieve a thermally isotropic oscillator environment. Wide-area uniform heat transfer promotes high thermal gain and minimizes thermal gradients. Another factor is the geometry and circuitry for temperature monitoring. Temperature sensors are equidistantly spaced from each other and are equidistant from the center of the oven chamber. Signals from the various thermistors are averaged to provide a more accurate temperature determination for regulating the heaters.

Abstract: In order to realize highly accurate temperature compensation of a crystal oscillation frequency, a current in proportion to the cube of a difference between an ambient temperature T.sub.a and a reference temperature T.sub.0 is generated. For this purpose, provided are a first series circuit of two diodes; a second series circuit of three diodes; a third series circuit of two diodes; a fourth series circuit of three diodes; a current source for allowing a constant current to flow into the first series circuit; a current source for allowing a constant current to flow from the third series circuit; a current source for allowing a current in proportion to T.sub.a -T.sub.0 to flow into the second series circuit when T.sub.a .gtoreq.T.sub.0 and allowing a current in proportion to .vertline.T.sub.a -T.sub.0 .vertline. to flow from the fourth series circuit when T.sub.a <T.sub.

Abstract: An acceleration sensor includes a vibrator and a plurality of pairs of piezoelectric elements which are arranged so as to confront each other through the vibrator. The vibrator is structured so as to be uniformly deformed in accordance with temperature variations. Two pairs of the confronting piezoelectric elements are polarized in opposite directions. An oscillation circuit is connected between the piezoelectric elements and the vibrator to supply the piezoelectric elements with the same driving signals. A first differential circuit is connected to one pair of piezoelectric ceramic elements and a second differential circuit is connected to the other pair of piezoelectric ceramic elements. A third differential circuit is connected to receive the outputs of the first and second differential circuits and provides the output of the acceleration sensor.

Abstract: In a digital temperature compensated crystal oscillator, ADC circuit and DAC circuit are combined into a data conversion circuit which comprises a first section for DA conversion, a second section for converting an analog temperature voltage signal into a digital form in cooperation with the first section, and a third section for supplementing the DA conversion of the first section and thereby generating an analog control voltage for a VCO from a digital temperature compensation data. There is further provided a switch circuit for connecting the output of the first section to either of the second and third section.

Abstract: A substantially sealed frequency source (10) including a crystal oscillator (14) and a programmable IC (22) thermally and electrically coupled on a substrate (12). The IC (22) is accessed through an interface (26) with programming signals (42) so as to provide an analog temperature control signal (34) and a crystal oscillator frequency adjustment signal (36). The substrate (12) maintains a substantially constant temperature at a turning point (82) on a frequency-temperature response curve (80) of the crystal (64). The IC (22) allows programming of the source (10) after sealing to compensate for shifts in the crystal frequency-temperature response (80) due to sealing. The IC (22) provides electrical correction of the substrate temperature setpoint and the crystal oscillator frequency without mechanically or thermally disturbing the internal components of the source (10).

Abstract: An acoustical resonator comprising top and bottom electrodes that sandwich a PZ layer. The resonance frequency of the acoustical resonator may be adjusted after fabrication by utilizing heating elements included in the acoustical resonator and/or by adjusting the thickness of a tuning layer. In the preferred embodiment of the present invention, the electrodes comprise Mo layers. One embodiment of the present invention is constructed on a Si.sub.3 N.sub.4 membrane. A second embodiment of the present invention is constructed such that it is suspended over a substrate on metallic columns. In the preferred embodiment of the present invention, the electrodes are deposited by a method that minimizes the stress in the electrodes.

Abstract: A vibration type actuator device, and particularly a vibration type actuator device is heated for a predetermined time at the starting of the actuator device, and is operated thereafter.

Abstract: A vibration control apparatus that can impart stabilized self-induced vibration without amplitude changes even under changes in ambient temperature is disclosed. When the apparatus is used with a vibrating gyroscope, detection accuracy is increased without temperature dependence of detection sensitivity on input angular velocity. The vibration control apparatus imparts self-induced vibration to a vibrator which has a pair of piezo-electric elements on the side surface of a vibration member having a resonance point. The vibrator is given self-induced vibration while the combined current value of the respective currents flowing through the pair of piezo-electric elements is held fixed. A drive signal output circuit outputs a drive signal applied to the pair of piezoelectric elements and has a voltage gain with a temperature dependence corresponding to the temperature dependencies of the equivalent resistances of the vibrator.

Abstract: A pressure sensor comprises a movable structure which is movable in accordance with a pressure applied thereto. A piezoelectric transducer is employed against which a pressure is applied when the movable structure is moved. The transducer has opposed electrodes between which a voltage is generated when the transducer is pressed. The capacitance between the opposed electrodes increases with increase of temperature. A dielectric member is arranged in the vicinity of the piezoelectric transducer. The dielectric member has opposed electrodes the capacitance between which decreases with increase of temperature. The piezoelectric transducer and the dielectric member are electrically connected in series.

Abstract: A driving circuit which drives piezo element connected to a movable member, thereby moving the movable member. A current from a DC power source flows in an induction device. During each drive cycle, a switch mechanism cuts the current in the induction device to induce a driving voltage from the induction device. The switch mechanism cuts the current in the induction device at a first moment in a respective drive cycle occurring when the current is increasing. The driving voltage becomes substantially flat at a second moment during the respective drive cycle occurring after the first moment in the respective drive cycle. A voltage detection device detects the driving voltage induced from the induction device and compares the driving voltage with a predetermined reference level. In accordance with the comparison by the voltage detection device at the second moment during each drive cycle, a control unit determines a first moment for the next drive cycle.

Abstract: A piezoelectric actuator is driven by continuously applying a pulse voltage or an AC voltage to a piezoelectric element, so as to cause the piezoelectric element to generate heat because of a dielectric loss of the piezoelectric element itself. If the temperature of the piezoelectric element reaches a temperature not less than 15.degree. C., moisture contained in atmosphere is effectively prevented from entering into a resin casing of the piezoelectric actuator enclosing therein the piezoelectric element. Otherwise, moisture condensation or sweating would occur on a surface of the piezoelectric element. Therefore, even if the piezoelectric actuator is used in atmosphere of high humidity, a discharge breakdown will not occur, and reliability is remarkably increased.

Abstract: A method of manufacturing is employed to produce a size-reduced frequency control device (300), according to the present invention. A temperature compensation circuit (304) and an unsealed piezoelectric element (302) are disposed on a substrate (306) such that the compensation circuit and the unsealed piezoelectric element are electrically connected. A hermetic seal (318) is established between a lid (308) and the substrate such that the unsealed piezoelectric element and at least a temperature sensitive portion of the temperature compensation circuit occupy a sealed environment (320). In this manner, dimensions (322, 324) of the frequency control device are reduced.

Abstract: An electronic circuit including a frequency-selective part including a piezoelectric crystal and an inductance; The crystal is shaped relative to its crystal axes in such a way that its temperature coefficient and the temperature coefficient of the inductance have opposite signs in order to reduce the influence temperature on the pulling range of the frequency-selective part of the circuit.

Abstract: A Colpitts-type oscillation circuit, employing a ceramic resonator vibrating in the energy trapping thickness shear slide mode is disclosed in which, an antiresonance frequency of the ceramic resonator has a negative temperature characteristic which is less step than that of its resonance frequency. Capacitance between terminals of the ceramic resonator is set so that an oscillation frequency (Fosc) of the oscillation circuit at the ordinary temperature is higher than a central frequency ((Fr+Fa)/2) of the ceramic resonator. Thus, it is possible to employ a ceramic resonator having a large bandwidth (.DELTA.F), thereby improving the temperature characteristic of the oscillation frequency.

Abstract: To drive a piezoelectric element for use in a dot matrix printer for a period of time defined by .pi.LC/2, the fact that the electrostatic capacitance C of a piezoelectric element changes depending on the temperature thereof is considered. The piezoelectric element is supplied with a voltage from a D.C. power source when a switching transistor is being ON. A temperature sensor is provided which senses the temperature of the piezoelectric element. A microcomputer serving as a control circuit has a ROM in which ON durations Ton for the switching transistor are stored in relation to temperatures to be output from the temperature sensor. At the time of printing, a suitable ON duration corresponding to the sensed temperature is selected by the control circuit from the table so that the piezoelectric element is always displaced the same amount independently of the temperature of the piezoelectric element.

Abstract: A system and method for compensating in real time the dynamic power variation of a computer chip containing CMOS devices is provided. The present invention functions to control the temperature variations on the chip thus eliminating the drift to analog signals associated with CMOS devices. The present invention controls the temperature with the use of a compensation heater located on the CMOS chip. The compensation heater is driven by a plurality of signals which act in harmony with one another to control the temperature on the chip when it becomes unstable. The system and method includes driving the compensation heater with a maximum dynamic power value to effectively maintain the temperature on the chip, evaluating the chip for temperature fluctuation, and compensating for the temperature fluctuation by driving the compensation heater with at least one compensation power value.

Abstract: A method of directly bonding a crystal to a crystal includes the steps of mirror-polishing the surfaces of the crystals and then rinsing them with a cleaning material and then affecting a baking operation and then bonding them together and thereafter annealing them within a temperature range where crystal crystallization is not transited in phase so that a further strong bonding force is obtained. A crystal resonator is obtained where electrodes are oppositely established across a ply crystal blank with at least two sheets of crystal blanks having a desired cut angle and a desired thickness being directly bonded so that the respective crystal axes intersect at the desired angles. The ply crystal blank may have a central portion which is either thicker or thinner than a surrounding portion.

Abstract: A low frequency sonar projector for use with a projector array having at least one ceramic stack comprised of lead magnesium niobate-lead titanate (PMN-PT) having a Curie temperature Tm approximately equal to the operating temperature of the projector. A mechanism is provided for applying heat to and for controlling the temperature of the ceramic stack to within a fixed operating range. A biasing circuit is included for providing a first electrical signal to polarize the ceramic stack. A driving circuit is also included for providing a second electrical signal to generate an output signal from the ceramic stack. Finally, a mechanism is included for transmitting the output signal from the ceramic stack to a fluid medium. In a preferred embodiment, a PMN-PT ceramic stack is in intimate enclosed contact with an elliptical-shaped outer projector shell. The Curie temperature Tm of the PMN-PT is selected to maximize the electrostrictive effects of the ceramic stack (102) for improving projector performance.

Abstract: A temperature compensated oscillator and a temperature detector have a temperature sensor having a single case in which a pair of AT cut crystal resonator having substantially the same natural oscillation frequency and different cut angles from each other are accommodated. The crystal resonators each constitutes the resonance circuit of respective one of two oscillation circuits. A difference in frequency between the output frequencies of the oscillation circuits is representative of a detected temperature.

Abstract: A crystal oscillator for generating an output oscillation whose frequency is maintained constant independently of the variation of temperature including a first quartz vibrator arranged in a heating unit which includes a thermostat and vibrating at a fundamental frequency, a second quartz vibrator arranged also in the same heating unit and vibrating at a third overtone frequency, a frequency multiplying circuit for multiplying the fundamental frequency by three, a frequency comparator for comparing the fundamental frequency multiplied by three with the third overtone frequency to derive a frequency difference which represents a temperature of the thermostat, and a temperature controlling circuit for controlling the temperature setting of the thermostat in accordance with the detected frequency difference. Any one or both of the fundamental and third overtone oscillations may be derived as an output oscillation.

Abstract: A structure for a piezo film impact detector eliminates or minimizes false outputs due to pyroelectric effects. The detector structure has particular application to outdoor and underground use.

Abstract: In order to compensate for the effects of temperature variations on a transducer such as a piezo-resistive bridge, the bridge is fed from a temperature dependent power supply circuit. The power supply circuit comprises a temperature sensitive element with first and second adjustment means for adjusting the slope of supply voltage for the transducer against temperature on first and second sides, respectively, of a predetermined temperature. The second adjustment means provides an adjustment which is independent of the first adjustment means so that repeated temperature cycling during calibration is unnecessary.

Abstract: A resonator heating element is attached to the surface of a crystal resonator. Resonator temperature sensing may be accomplished either by a sensor attached to the crystal enclosure, or through dual mode temperature sensing, or by both. A control system converts the sensed temperature into a series of variable-width pulses applied to the resonator heating element. Thus, the temperature sensing mechanism(s), 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. In an especially preferred embodiment, an integrated circuit from a switching power supply may be used in a novel manner to perform certain of the functions in the temperature feedback control loop. Plural resonators may be present in the enclosure, one of which may be directly involved in temperature sensing. In other embodiments, a ring-shaped insulative structure may additionally be disposed between the resonator and its enclosure.

Abstract: A dot-matrix impact printer, including a print head including a piezoelectric element, and a print wire which is movable from a non-operated position thereof to an operated position thereof, owing to displacement of the piezoelectric element, to produce an imprint on a surface of a recording medium. The printer uses a piezoelectric control device which is responsive to a wire activation command, for applying a controlled drive voltage to the piezoelectric element to thereby activate the print wire to the operated position, wherein the drive voltage includes a static voltage which decreases with increasing paper thickness and which gets the wire close to the paper, and a dynamic voltage which provides the print force and increases with increasing paper thickness.

Abstract: A device utilizing a quartz crystal resonator with an orientation substantially equal to 21.93.degree./34.10.degree.. The crystal resonator is capable of vibrating simultaneously in two thickness modes, namely the B-mode and the C-mode. Because of the nature of the difference between the B- and C-modes, the B-mode may be used as an indication of the resonator temperature in order to compensate the C-mode frequency signal. A digital technique for temperature compensation by using the crystal itself as a sensor and a feedback loop varies the heater on the surface of the crystal. The temperature sensor compensation system contains a quartz resonator with a heater affixed thereon. The resonator is arranged as part of the oscillator to generate both B-mode and C-mode frequency signals. The C-mode signal is used as a time standard or frequency reference. Initially, the frequency of the B-mode is counted. The count is started at the same time the frequency count of the C-mode is initiated.

Abstract: A quartz crystal resonator is situated in an enclosure whose interior is substantially a vacuum. A heating element is attached to the crystal surface. A sensor is attached to the crystal enclosure, and may be sandwiched between the crystal enclosure and the circuit board to which the crystal enclosure is attached. A control system converts the sensed temperature into a series of variable width pulses applied to the resonator heating element. Thus, the sensor, control unit and heating element comprise a temperature feedback control system which allows the crystal to operate at or very near its desired temperature. Further, the crystal enclosure may be substantially surrounded by an external material insulator. The external material insulator maximizes thermal resistance between the sensor and the environment in comparison to the thermal resistance between the crystal and the sensor.

Abstract: In a liquid injection recording method, the falling time of a voltage pulse applied to electromechanical converting means for generating energy for discharging liquid droplets to a recording medium is made longer under a high temperature environment than under a room temperature environment.

Abstract: An impact dot-matrix printer having a print head which includes a piezoelectric element and a print element such as a print wire activated by the piezoelectric element, wherein the print head is movable between a printing area and a non-printing area of the printer. A pressure detector is provided for detecting a printing pressure of the print element. The detector includes a pressure-sensitive element which is disposed in a predetermined position in the non-printing area, in which the print element is operable to act on the pressure-sensitive element. A voltage controller connected to the pressure detector and the piezoelectric element is provided for controlling a voltage applied to the piezoelectric element, based on an output of the pressure detector, such that the printing pressure coincides with a predetermined value.

Abstract: In a driving circuit for a piezoelectric ultrasonic motor (23) supplying driving signal from an astable oscillator (51), which comprises an oscillation IC (49), a capacitor (48) and charge-discharge resistors (45, 46, 47), is controlled by controlling leakage current through a leakage resistor (47) to a point E, through controlling of the voltage of the point E by a temperature-dependent voltage producing circuit 52.

Abstract: A high stability quartz crystal oscillator is made from a quartz crystal te by first cutting the quartz crystal plate at the angles that result in a resonator having a turnover temperature below the lowest operating temperature of the equipment in which the oscillator is to be used. A resonator is made from the quartz plate; the resonator when connected into a high stability oscillator circuit, and the oscillator-circuit/resonator combination placed into a temperature controlled environment where the temperature is maintained at a temperature between the lowest operating temperature of the equipment in which the oscillator is to be used to about -250.degree. C.

Abstract: An improved gas density transducer which compares the resonant frequency of an enclosed, reference tuning fork crystal oscillator with the resonant frequency of a detector tuning fork crystal oscillator exposed to the surrounding gas. The frequency of oscillation of the detector crystal oscillator exposed will vary in accordance with the gas density because of the motional resistance of the gas to vibrations of the tuning fork oscillator. The frequency of the detector oscillator can be compared to the frequency of the reference oscillator to determine the gas density.

Abstract: A frequency locked loop having a surface acoustic wave time delay device disposed on the same substrate, or a substrate on the same material, as a surface acoustic wave device being compensated. As temperature causes changes in the surface acoustic wave device, changes in the time delay of the surface acoustic wave time delay device will also occur. These changes in the time delay are used by the frequency locked loop to adjust the frequency of an incoming signal of the frequency locked loop and to provide an adjusted input signal frequency to the surface acoustic wave device. This adjusted input compensates for the change in the output caused by the temperature change.

Abstract: A surface acoustic wave (SAW) device provides a phase shift and a first predetermined phase shift variation as a function of temperature. A passive network including a passive, reactive component is thermally and electrically coupled to the SAW device. An electrical characteristic of the component has a predetermined variation as a function of the temperature of the reactive component which provides the network with a second, predetermined phase variation as a function of temperature to compensate for the first predetermined phase variation as a function of temperature provided from the surface acoustic wave device. With this arrangement, the phase shift provided from the surface acoustic wave device is substantially invariant with temperature.

Abstract: A displacement generation device includes: a bimorph piezoelectric vibrator for receiving an externally applied drive voltage and for generating a displacement in response to the drive voltage; and a temperature-compensation capacitor element electrically connected in series with the piezoelectric vibrator. The capacitor element has a capacitance with a temperature coefficient with the same absolute value but opposite sign to that of the capacitance of the piezoelectric vibrator. When the capacitance of the piezoelectric vibrator changes in accordance with a change in the ambient temperature, the capacitor element properly changes the drive voltage supplied to the piezoelectric vibrator, thereby compensating for the displacement of the piezoelectric vibrator caused by the change in ambient temperature.

Abstract: An apparatus for controlling the temperature of a device whose temperature is to be stabilized within a preset range is disclosed. The apparatus is particularly applicable to stabilizing the temperature, and thus frequency of operation of, a crystal controlled oscillator, without expending additional energy in specialized crystal heating apparatus. The apparatus preferably includes first and second power supply regulators coupled to a source of unregulated voltage. The second power supply regulator preferably has a higher output voltage than the first power supply regulator and the outputs of the two regulators are coupled together. The cyrstal is attached to the second regulator so that heat generated by the second regulator is dissipated in the crystal. A temperature sensing device is coupled to the crystal and generates a signal proportional to the temperature of the crystal.