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:
Nov. 19, 2013
Filed:
Feb. 18, 2009
Katsuyuki Sugita, Osaka, JP;
Nobukazu Ikeda, Osaka, JP;
Kouji Nishino, Osaka, JP;
Ryousuke Dohi, Osaka, JP;
Kaoru Hirata, Osaka, JP;
Takatoshi Nakatani, Osaka, JP;
Katsuyuki Sugita, Osaka, JP;
Nobukazu Ikeda, Osaka, JP;
Kouji Nishino, Osaka, JP;
Ryousuke Dohi, Osaka, JP;
Kaoru Hirata, Osaka, JP;
Takatoshi Nakatani, Osaka, JP;
Fujikin Incorporated, Osaka, JP;
Abstract
A pressure control valve piezoelectric element driving circuit is provided for a pressure type flow rate control device provided with a flow rate self-diagnosis function for comparing initial pressure drop characteristics data measured and with pressure drop characteristics data in a flow rate diagnosis which are measured under conditions that are the same for both measurements to detect malfunction in flow rate control from a difference between both characteristics data, wherein a first discharge circuit slowly discharges a piezoelectric element driving voltage applied to the piezoelectric element according to a step-down command signal from a CPU, through a step-down command circuit to step down the voltage, and a second discharge circuit that rapidly discharges a piezoelectric element driving voltage applied to the piezoelectric element according to a high-speed step-down command signal from the CPU, through a high-speed step-down command circuit to step down the voltage.