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:
Aug. 06, 2013
Filed:
Apr. 21, 2011
Ichirou Mitsutake, Tokyo, JP;
Ichirou Mitsutake, Tokyo, JP;
Azbil Corporation, Tokyo, JP;
Abstract
A noise eliminating circuit is provided between a sample hold portion and an A/D converting portion. In the noise eliminating circuit, a DC flow rate signal is sent from the sample hold portion through a buffer to one input terminal of an operational amplifier as a first input signal, and through a high-pass filter and a buffer to the other input terminal of the operational amplifier as a second input signal. The high-pass filter passes, as a noise component, a signal of higher than a specific frequency included in the DC flow rate signal. The operational amplifier calculates the difference between the first input signal (the flow rate signal component+the noise component) and the second input signal (the noise component), and outputs this difference (the flow rate signal component) to the A/D converting portion as the DC flow rate signal.