PURPOSE: To improve the response characteristic of a piezoelectric vibrator by providing a means controlling the operation of an oscillator so as to vibrate minutely a piezoelectric vibrator before a desired vibration start timing.
CONSTITUTION: When an output of an operational amplifier 2 is impressed to a piezoelectric element 1a, the element 1a is deformed in lengthwise direction. This deformation is delivered to a piezoelectric element 1b via a piezoelectric vibrator 1, the element 1b is subjected to distortion and a voltage is generated. A voltage generated in the piezoelectric element 1b is impressed to an inverting input of an amplifier circuit comprising an operational amplifier 2, a resistor and a capacitor. An output voltage of the piezoelectric element 1b is amplified with respect to a reference voltage applied according to the voltage dividing ratio of resistors 5a, 5b from a constant voltage circuit, and the amplified output whose phase shift is adjusted is impressed to the piezoelectric element 1a again. A constant voltage is applied to the closed loop oscillating circuit from an external power supply 6. Further, the minute vibration of the vibrator is started before the desired timing by controlling the power supply 6.
SUZUKI KOUJI
NAGAHIRA JIYOUJI
TAKAHASHI KAZUYOSHI
YOSHIHARA KUNIO
MATSUI TOSHIAKI
