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:
Jun. 12, 1990
Filed:
May. 05, 1989
Sadayasu Ueno, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A piezoelectric detector for detecting a physical quantity comprising, a piezoelectric device having a first electrode and a second electrode for modulating a carrier A.C., signal a excitation power source for supplying the carrier A.C. signal to the first electrode so as to excite the piezoelectric device, a weight mechanically coupled to the piezoelectric device so as to add the physical quantity to the piezoelectric device, an A.C. amplifier for amplifying a modulated output from the second electrode, and a demodulator for demodulating an amplified output from the A.C. amplifier. The piezoelectric detector measures the physical quantity while having a very low frequency range which D.C. includes.