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 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: The present invention relates to a piezoelectric resonator having adherent or non-adherent electrodes, the piezoelectric crystal comprising a central portion and a peripheral portion forming a ring that surrounds the central portion and that is connected thereto by an intermediate portion in which a slot is formed, the peripheral portion being connected to the central portion by a single connection bridge constituted by a non-slotted portion of said intermediate portion that extends over a small fraction of the periphery of said intermediate portion. The central portion constitutes the active vibrating portion of the crystal and the peripheral portion is held in the box by fastening means disposed in such a manner as to be thermally as remote as possible from the single connection bridge. The secured portion and the bridge constitute means for suspending the crystal.

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 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: Heat-generating ovenized crystal oscillators can be directly mounted to a circuit board. Thermal isolation of an OCO from heat-sinking circuit board material and other temperature-sensitive components on a circuit board is accomplished by means of perforations (12) in the circuit board that surround the mounting area of the OCO on the board.

Abstract: A piezoelectric resonator (1) consists of a piezoelectric reed (2) encased in a housing composed of a cap (7) and a base (8). The resonator (1) is placed in a thermostatically controlled containment (10). The thermostatically controlled containment (10) consists of an inner cell (40) which is screwed into an outer cell (30). These cells (30, 40) each possess sides (34, 44) and a bottom (35, 45). A thermal seal (16) is inserted between the bottom (35) of the outer cell (30) and the bottom (45) of the inner cell (40). The cap (7) of the resonator is soldered over its entire outer surface to the sides (44) and to the bottom (45) of the inner cell (40). The thermostatically controlled containment (10) is placed in a secondary containment (21). A narrow space (22) separates the two containments (10, 21), and the surface of the contact between the two containments is as small as possible. The invention is used for ultrastable on-board oscillators.

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: An ovenized oscillator having a temperature sensitive section of an oscillator and a heater supported in a chamber within an enclosure having an insulating gas surrounding the oscillator section and heater. Insulating walls may be added within the chamber to reduce convective heat loss through the gas. These walls form cavities around the oscillator section and are separated from each other except for small vent holes to equilibrate the pressure between cavities.

Abstract: A contact heater arrangement is disclosed for a piezoelectric effect crystal resonator. The piezoelectric effect crystal element may be an SC cut quartz crystal disc having electrodes affixed to one side thereof to generate a lateral field in the crystal disc. The contact heater element is applied to the side of the crystal element opposite the side on which the electrodes are affixed. The particular pattern of the heater leaves the center of the crystal element exposed for frequency adjustment purposes. Locating the heating element and electrodes on opposite sides of the crystal element generates a constant temperature which has been found effective to uniformly heat a piezoelectric effect crystal element, and with appropriate control circuitry, allows for temperature stabilization of the crystal element.

Abstract: This invention relates to a thermostatted oscillator comprising an assembly support constituted by a printed circuit provided with an opening, on the edge of which is fixed, at a reduced number of points, an electrically insulating secondary support on which are fixed, on the one hand, a piezo-electric resonator and, on the other hand, a prediffused circuit comprising in integrated form the essential elements of the electronic circuits for regulating the supply voltage of the assembly, of the electronic circuits for maintaining and amplifying the oscillations of the resonator, and of the electronic circuits for regulating the temperature of the resonator. The invention is more particularly applicable to miniature oscillators of high stability and low consumption.

Abstract: A method and a device for regulating the heating of a thermostatically controlled enclosure of a quartz oscillator. During a first stage, the thermostatically controlled enclosure is exposed to an external temperature close to the maximum operating temperature and the frequency of the oscillator is measured. During a second stage, the thermostatically controlled enclosure is exposed to an external temperature close to the minimum temperature of the range and the difference between the frequency of the oscillator and the frequency previously measured is cancelled out by modifying the distribution of the powers dissipated by the heating elements of the thermostatically controlled enclosure. The heating of the enclosure is performed by a chain of voltage stabilizer semiconductor circuits connected in series, each of the circuits being traversed by a regulated heating current. The regulating of the heating action is performed by modifying the stabilized voltages of the circuits.

Abstract: This invention is directed to a narrow band filter for eliminating out-of-band noise in the oscillator signal of a doppler radar system. It provides a very high Q filter derived from a Bulk Acoustic Resonator's (BAR) high Q, L-Band response and uses thermal feedback to lock the BAR's response band onto the input frequency. The BAR is a very narrow band filter with a Q near 40,000 and a comblike frequency response having passbands occurring every 5 MHz, approximately. The comblike response of the BAR shifts down 60 KHz for every 1.degree. C. rise in temperature. In this invention a frequency sensitive heater is used to move the response comb of the BAR up or down in accordance with changes in the frequency of the incoming signal. The input frequency can be allowed to drift and the heat source will produce more heat or less heat, keeping the response right at the input frequency.

Abstract: A resonator with an integrated infrared thermostat, having a sealed casing enclosing reflectors including concave spherical domes covered with an interior coating of reflecting metal, placed on either side of a piezoelectric crystal, an infrared heating means device positioned on either side of the crystal in front of the spherical domes, and a temperature sensor including a thermocouple of two thin metal layers superimposed seriatim on one side of the active part of the crystal and constituting additionally and simultaneously one of the excitation electrodes for the crystal.

Abstract: A device for regulating the temperature of an electronic component, such as a surface acoustic wave (SAW) component in a hybrid package, without dissipating large amounts of power. The device includes a positive-temperature-coefficient thermistor positioned in contact with the component of which the temperature is to be controlled, and an insulating body with included air spaces, positioned between the thermistor and the package, to provide a high thermal resistance between the thermistor and the package. In one preferred form of the invention, the insulating body is a length of glass tubing that has been deformed to include two flat surfaces for contacting the thermistor and the package. Another disclosed embodiment includes a second thermistor and insulator combination, to further increase the thermal resistance between the component and the package.

Abstract: The disclosed temperature-compensated crystal resonator unit has a crystal resonator element with a first ceramic member attached thereto, which resonator element is housed in a vessel with a second ceramic member being mounted on the housing and electrically connected to said first ceramic member in series thereto, both of said first and second ceramic members having positive temperature coefficients of electric resistance, said second ceramic member being mechanically separated from both the first ceramic member and the crystal resonator element.

Abstract: An autothermostatic high frequency oscillator comprising a piezoelectric resonator of the type having electrodes which are not adhered to the crystal. The contact between the part of the crystal 1 serving to support the vibrating part of the crystal and the dielectric plates 2,3 supporting the excited electrodes is limited to a discontinuous surface of reduced scope constituted by a finite number of elements of contact surface. At least an infra-red reflector screen (200) located at the very interior of the water tight cavity (400) surrounding the resonator is situated immediately adjacent said resonator and the electric power applied to the excited electrodes is at least in the range of about 50 microwatts. The invention permits one to achieve oscillators with small consumption of energy and high stability.

Abstract: A process and apparatus are disclosed for heating a piezoelectric crystal sonator by infrared radiation.

Abstract: A crystal oven for radio frequency control crystals includes a crystal socket board, mounted directly on one side of a printed circuit board. The crystal sockets extend through and are soldered to corresponding cyrstal socket terminals on the opposite side of the printed circuit board. A housing surrounds the crystal socket board and is attached to the printed circuit board. An oven temperature control circuit including a power transistor controls the amount of current flowing through a heating wire, which is wrapped around and mounted to the housing. The collector plate of the power transistor is mounted to a heat sink, which overlies the crystal socket terminals. Heat generated by the collector plate as a result of current through the power transistor is distributed across the heat sink and is transferred by convection to the crystal socket terminals to reduce the amount of heat transfer through the crystal socket terminals.

Abstract: Heating electrode means provided directly on a quartz vibrator body in a specific angular range does not effect on the change in the resonant frequency which is normally to be caused by direct heating of the body so that a highly stable piezoelectric quartz vibrator can be provided without a constant temperature box.

Abstract: A unitary molded socket provides mounting for non-temperature compensated crystals, a resistor heating element for each crystal, and a thermistor. Each heating element is positioned adjacent a crystal housing for preventing the housing temperature from going below a given temperature. The thermistor is thermally coupled to one of the resistors for sensing its temperature and electrically coupled to control circuitry for providing the appropriate heating current to the resistor heating elements. A spring clip biases each crystal against its resistor, clamps it into the socket and is pivotable for replacement of components.