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. 01, 2022
Filed:
Aug. 02, 2021
Hitachi Astemo, Ltd., Hitachinaka, JP;
Nuvoton Technology Corporation Japan, Nagaokakyo, JP;
Atsushi Ogawa, Hitachinaka, JP;
Motoaki Kato, Hitachinaka, JP;
Kengo Nomura, Hitachinaka, JP;
Keisuke Kuroda, Osaka, JP;
Makoto Kawajiri, Kyoto, JP;
HITACHI ASTEMO, LTD., Hitachinaka, JP;
NUVOTON TECHNOLOGY CORPORATION JAPAN, Nagaokakyo, JP;
Abstract
An electromagnetic valve drive device which supplies a hold current with a prescribed fluctuation range to an electromagnetic coil of an electromagnetic valve after a current peak when a supply of electricity starts has passed includes: a power supplier which intermittently applies a drive voltage to the electromagnetic coil; a detector which detects the hold current; a first comparator which compares a detected current by the detector with a first threshold value; a filter which performs integration processing on an output of the first comparator; a second comparator which compares an output of the filter with a second threshold value to generate an output signal used for generating a control signal for controlling the power supplier; and a control signal generator which generates the control signal for controlling the power supplier based on the output signal of the second comparator, wherein the filter is a count-up/down type digital filter.