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:
Oct. 03, 2000
Filed:
Nov. 25, 1998
Masatoshi Kuwayama, Chiryu, JP;
Yasunobu Hirao, Toyokawa, JP;
Shigeru Takeuchi, Gamagori, JP;
Takafumi Ito, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
A cooling apparatus for automotive use wherein speed of an electric cooling fan is controlled solely at a predetermined speed. When a relay switch is switched on, voltage of a battery is applied to a lag circuit. Output of the lag circuit is applied to a gate G of a MOS transistor, but rise of the gate-applied voltage is delayed by the lag circuit according to a time constant thereof, and increases slowly. When the gate-applied voltage reaches the threshold voltage of the MOS transistor, the MOS transistor begins to switch on. However, when the gate-applied voltage is low, the drain current flowing through the MOS transistor is limited and thereby surge current at the motor is minimized.