Abstract: A variable capacitance unit that configures a voltage controlled piezoelectric oscillator including a first variable capacitance diode, a first condenser connected in parallel with the first variable capacitance diode, the second variable capacitance diode, a second condenser inserted and connected between a cathode of the first variable capacitance diode and an anode of the second variable capacitance diode, a third condenser inserted and connected between an anode of the first variable capacitance diode and a cathode of the second variable capacitance diode. The external control voltage is applied to the first variable capacitance diode and the second variable capacitance diode so that respective polarities thereof are reversed.

Abstract: The high-strength non-combustible magnesium alloy is obtained by adding at least one supplementary additive selected from among carbon (C), molybdenum (Mo), niobium (Nb), silicon (Si), tungsten (W), alumina (Al2O3), magnesium silicide (Mg2Si) and silicon carbide (SiC) to small chip-like blocks of a non-combustible magnesium alloy resulting from adding 0.5 to 5.0% by mass of calcium to a magnesium alloy to produce a crushed product, and subjecting the same to forming, sintering and plastic working. The high-strength non-combustible magnesium alloy exhibits excellent joining ability, and can therefore enhance weldability when used in a filler metal.

Abstract: In conventional frequency control by single-direction voltage control to a variable capacitance diode, there is a limit in an amount of correction for obtaining a straight line. The variable capacitance unit that configures a voltage controlled piezoelectric oscillator comprises a first variable capacitance diode, a first condenser connected in parallel with the first variable capacitance diode, the second variable capacitance diode, a second condenser inserted and connected between a cathode of the first variable capacitance diode and an anode of the second variable capacitance diode, a third condenser inserted and connected between an anode of the first variable capacitance diode and a cathode of the second variable capacitance diode. The external control voltage is applied to the first variable capacitance diode and the second variable capacitance diode so that respective polarities thereof are reversed.

Abstract: In order to remove external noise of the same phase, such as a power supply noise, on an crystal oscillator, one oscillation output has been conventionally obtained from one oscillation circuit, and by using a differential amplifier, the one oscillation output is turned into two oscillation outputs that are 180 degrees out of phase. However, it has been impossible to remove the noise of the same phase that occurs in the oscillation circuit.

Abstract: In a piezoelectric oscillator a non-inverted output terminal (3) of an ECL circuit (10) is grounded via a capacitor (C3) and is connected to a non-inverting input terminal (5) of the ECL circuit (10) via a series connection of capacitors (C4) and (C5). The non-inverting input (5) is connected via a resistor R1 to an inverting input terminal (4) of the ECL circuit (10) and is grounded via a capacitor (C2). The connection point of the series connection of the capacitors (C4) and (C5) is grounded via a crystal oscillator (X'tal) and a frequency control capacitor (C1). The output from the ECL circuit (10) is provided at its inverted output terminal 2.

Abstract: A piezoelectric oscillator including a piezoelectric vibrator that vibrate at desired frequency; a first transistor for exciting the piezoelectric vibrator; a second transistor whose collector connects to an emitter of the first transistor, the second transistor being a base grounded type; a first capacitor connected between the emitter of the first transistor and ground; a series circuit comprising the piezoelectric vibrator and a second capacitor being connected between a base of the first transistor and an emitter of the second transistor, in which the first capacitor and a composition capacitance between base and emitter of the first transistor functions as a split capacitor for a feedback circuit of the Colpitts oscillator.

Abstract: Design means is provided to prevent electronic parts used in a high-stability piezoelectric oscillator from deterioration due to aging by heat when the high-temperature side of the working temperature range is as high as 85° C. A high-stability piezoelectric oscillator, which is provided with a first constant temperature oven having housed therein a piezoelectric resonator and electronic parts for oscillation, a second constant temperature oven having housed herein said first constant temperature oven, and temperature control means for controlling the temperature of each constant temperature oven, and in which the temperature of said first constant temperature oven is set lower than the temperature of said second constant temperature oven, is characterized in that a heat source is disposed near said piezoelectric resonator.

Abstract: A highly stable piezoelectric oscillator includes a heat-generating component mounted on a base printed circuit board; an erected printed circuit board placed upright on the base printed circuit board by fitting a fitting end part in a fitting slit that is formed to penetrate the base printed circuit board; a piezoelectric resonator which is disposed horizontally and directly on the heat-generating component on the base printed circuit board and whose lead electrode part is connected and fixed on the erected printed circuit board; and an oscillation circuit component to obtain an oscillation output using the piezoelectric resonator as a frequency source.

Abstract: A piezoelectric oscillator includes an inverter amplifier, a first load impedance constituting together with the inverter amplifier a connection circuit that is inserted between the power supply and the ground, a piezoelectric resonator being inserted between the input of the inverter amplifier and the ground, a second load impedance being serially inserted and connected between the input of the inverter amplifier and a connecting point of the inverter amplifier and the first load impedance, and a resistor being connected between the input and an output of the inverter amplifier.

Abstract: A piezoelectric oscillator using a pair of first and second inverter amplifiers, includes a piezoelectric vibrator inserted between gate inputs of the first and second inverter amplifiers; load capacitors inserted between a ground and each of the gate inputs of the first and second inverter amplifiers; and resistors inserted between an input and an output of each of the first and second inverter amplifiers. In the piezoelectric oscillator, the output terminal of the first inverter amplifier is connected to the input terminal of the second inverter amplifier by a first capacitor for cutting direct current, and the input terminal of the first inverter amplifier is connected to the output terminal of the second inverter amplifier by a second capacitor for cutting direct current.

Abstract: A SC cut crystal microbalance includes a SC cut crystal oscillator, a C mode/B mode switching-type oscillation circuit, a frequency countermand a frequency information processing device, wherein the C mode/B mode switching-type oscillation circuit is switched by a signal received from the frequency information processing device, the frequencies of C mode and B mode is measured respectively, variations by temperature change are compensated from frequency variations of C mode based upon temperature information by the frequency change of B mode, and whereby mass change is measured.

Abstract: In an inverter oscillation circuit an output terminal 2 of an inverter 1 with its input and output interconnected via a high resistance R1 is grounded via a series connection of a capacitor C1 and parallel tuning circuit composed of a capacitor C2 and an inductor L1 connected in parallel, and the connection point of this series connection is grounded via a parallel circuit of diodes D1 and D2 connected in opposite polarities. The connection point of the series connection is connected to an input terminal 3 of the inverter 1 via series-connected capacitors C3 and C4, and the connection point of this series connection is grounded via a piezoelectric vibrator Xtal and a frequency adjusting capacitor C7. The inverter oscillation circuit is configured to provide its output via a series circuit composed of a resistor R2 and a capacitor C6.

Abstract: A thin and highly stable piezoelectric oscillator is provided with a piezoelectric vibrator, a mother printed board which supports a piezoelectric vibrator main body on its one face and connects lead terminals to a wiring pattern, oscillating circuit parts which are mounted on one face of the mother printed board to be disposed in close contact with one face of the piezoelectric vibrator main body, adjusting circuit parts which are mounted on the other face of the mother printed board, an internal printed board which is provided in contact with the other face of the piezoelectric vibrator main body, and heater resistors which are mounted on the internal printed board to be disposed in close contact with the other face of the piezoelectric vibrator main body.

Abstract: Design means is provided to prevent electronic parts used in a high-stability piezoelectric oscillator from deterioration due to aging by heat when the high-temperature side of the working temperature range is as high as 85° C. A high-stability piezoelectric oscillator, which is provided with a first constant temperature oven having housed therein a piezoelectric resonator and electronic parts for oscillation, a second constant temperature oven having housed herein said first constant temperature oven, and temperature control means for controlling the temperature of each constant temperature oven, and in which the temperature of said first constant temperature oven is set lower than the temperature of said second constant temperature oven, is characterized in that a heat source is disposed near said piezoelectric resonator.

Abstract: A piezoelectric oscillator including a piezoelectric vibrator that vibrate at desired frequency; a first transistor for exciting the piezoelectric vibrator; a second transistor whose collector connects to an emitter of the first transistor, the second transistor being a base grounded type; a first capacitor connected between the emitter of the first transistor and ground; a series circuit comprising the piezoelectric vibrator and a second capacitor being connected between a base of the first transistor and an emitter of the second transistor, in which the first capacitor and a composition capacitance between base and emitter of the first transistor functions as a split capacitor for a feedback circuit of the Colpitts oscillator.

Abstract: A piezoelectric oscillation circuit has a series circuit composed of a capacitor Cbe as a part of a load capacitance and a capacitor Ce inserted and connected between a base of an oscillation transistor TR1 and the ground, and has an emitter resistor Re connected to a connection midpoint A of the series circuit and an emitter of the oscillation transistor TR1. Further, a base bias circuit composed of a resistor RB 1 and a resistor RB2 is connected to a base of the oscillation transistor TR1, has a piezoelectric element Xtal and a capacitor C1 inserted and connected in series between the base of the oscillation transistor TR1 and the ground, and further has a resistor Rc connected to a collector of the oscillation transistor TR1 together with the power supply voltage Vcc line, and has a capacitor Cce connected between the collector and the emitter.

Abstract: The invention provides a temperature compensated crystal oscillator that can obtain a large variable range and that can obtain high temperature stability. This temperature compensation system employs a configuration comprising a oscillation circuit 12 including a crystal vibrator 11 having a piezoelectric element excited in a given frequency and an oscillation amplifier that excites the piezoelectric element by flowing a current to the piezoelectric element, a vibrator current control circuit 13 that controls the current of the crystal vibrator, a temperature compensation voltage generation circuit 15 that compensates for temperature characteristics of the crystal vibrator 11, and an external variable capacitance diode 17 that changes the oscillation frequency of the oscillation circuit 12 using an external variable voltage controller 16. The vibrator current control circuit 13 comprises a variable capacitance diode 14 that controls the vibrator current, and capacitors 1 to 3.

Abstract: The present invention has for its object to provide a piezoelectric oscillator that has improved secular variation characteristics and excels in suppressing undesired resonance.

Abstract: In the high-frequency piezoelectric oscillator, capacitors C1, C2 as a part of a load capacitor are connected between a base of a transistor TR1 and the ground. The connection point of the capacitors C1, C2 is connected to an emitter of the transistor TR1, and is grounded via an emitter resistor R1. A base bias circuit consisting of resistors RB1 and RB2 is connected to the base of the transistor TR1. A piezoelectric vibrator, an inductor, and a resistor are connected in parallel, and connected between the base of the transistor TR1. A capacitor is connected to the parallel circuit and grounded. A collector of the transistor and a power supply line are connected together.

Abstract: A piezoelectric oscillator for suppressing a vibrator current easily with a simple circuit configuration is provided. A piezoelectric oscillation circuit has a series circuit composed of a capacitor Cbe as a part of a load capacitance and a capacitor Ce inserted and connected between a base of an oscillation transistor TR1 and the ground, and has an emitter resistor Re connected to a connection midpoint A of the series circuit and an emitter of the oscillation transistor TR1. Further, a base bias circuit composed of a resistor RB1 and a resistor RB2 is connected to a base of the oscillation transistor TR1, has a piezoelectric element Xtal and a capacitor C1 inserted and connected in series between the base of the oscillation transistor TR1 and the ground, and further has a resistor Rc connected to a collector of the oscillation transistor TR1 together with the power supply voltage Vcc line, and has a capacitor Cce connected between the collector and the emitter.