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:
Mar. 18, 2014
Filed:
May. 29, 2012
Yoshiharu Ono, Kanagawa, JP;
Osamu Karino, Kanagawa, JP;
Yoshihiro Shimizu, Kanagawa, JP;
Yoshihiro Miyagawa, Kanagawa, JP;
Hiroyuki Kawajiri, Kanagawa, JP;
Takehiro Furukawa, Kanagawa, JP;
Yoshiharu Ono, Kanagawa, JP;
Osamu Karino, Kanagawa, JP;
Yoshihiro Shimizu, Kanagawa, JP;
Yoshihiro Miyagawa, Kanagawa, JP;
Hiroyuki Kawajiri, Kanagawa, JP;
Takehiro Furukawa, Kanagawa, JP;
Renesas Electronics Corporation, Kanagawa, JP;
Abstract
An electronic flow meter includes a magnetic sensor, phase-A and phase-B drivers, a phase-A comparator, a phase-B comparator, a two-phase encoder, and a rotational speed timer. The two-phase encoder determines a normal/reverse direction where the impeller is rotated based on event signals sampled by the phase-A and the phase-B comparators, respectively, causing a counter to count up or to count down according to the normal/reverse direction as determined, thereby outputting an event count signal. The rotational speed timer calculates a rotational frequency of the impeller from the event count signal outputted by the two-phase encoder and sets frequencies of respective sampling signals of the phase-A and the phase-B comparators at a time when the rotational frequency of the impeller is measured next, and respective drive periods of the phase-A and the phase-B drivers in accordance with the rotational frequency of the impeller as calculated.