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:
May. 09, 2006
Filed:
Nov. 27, 2001
Masayoshi Matsui, Ichinomiya, JP;
Koji Okazaki, Ichinoiya, JP;
Masayoshi Matsui, Ichinomiya, JP;
Koji Okazaki, Ichinoiya, JP;
NGK Spark Plus Co., Ltd., Aichi, JP;
Abstract
An object of the present invention is to provide a charge amplifier which can be operated at low cost so that electric charge generated in a piezoelectric pressure sensor having one end grounded is converted into a voltage signal. In the charge amplifier () according to an embodiment of the present invention, a plus side power source input terminal of an operational amplifier () is connected to a plus power source (+5 V) while a minus side power source input terminal of the operational amplifier () is grounded, so that the operational amplifier () is supplied with a single power source. Further, an offset voltage lower than the plus power source voltage but higher than the ground potential is applied to a non-inverted input terminal of the operational amplifier (). Accordingly, change of pressure in both positive and negative directions can be converted into a voltage signal with the offset voltage as its center though the operational amplifier () is driven by a single power source. That is, cost can be suppressed because a double power source is not required.