The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 27, 1998
Filed:
Dec. 21, 1995
Yoshiro Tomikawa, Ota-ku, Tokyo, JP;
Other;
Abstract
A driving circuit and a Self-oscillating circuit incorporating a piezoelectric oscillator having one terminal connected to ground. In the driving circuit, an alternating driving power is supplied to a first terminal of the piezoelectric oscillator, and the second terminal of the piezoelectric oscillator is connected to ground. The damping capacitance of the piezoelectric oscillator is effectively canceled by connecting the first terminal to an input of an amplifier, and forming a feedback loop by connecting an output of the amplifier to the input through a electrostatic capacitance whose value is 1/N times the damping capacitance of the piezoelectric oscillator, where the amplifier has a gain of (N+1). In the self-oscillating circuit, a frequency selection circuit is provided which includes a positive feedback circuit connected between an output and a non-inverting input of an amplifier, and an electrostatic converter including a first terminal connected to the positive feedback circuit, and a second terminal connected to ground. The positive feedback circuit includes an electrostatic capacitance and a resistor selected such that a self-oscillation frequency of the self-oscillation circuit is determined by said frequency selection circuit.