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. 09, 1999
Filed:
Dec. 30, 1996
Kazuo Otsuka, Wako, JP;
Hisahiro Ito, Wako, JP;
Sadao Shinohara, Wako, JP;
Yasumichi Ohnuki, Wako, JP;
Fumio Anraku, Wako, JP;
Shinji Yoshikawa, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
In an electric vehicle in which a motor is driven using the electric power of a battery, and a PWM controller controls an inverter mounted between the battery and the motor. The frequency of the PWM control means is usually set higher than an audio frequency, in order to decrease the switching noise of the inverter. Motor operational state detecting devices detect when the motor is at low speed and high-load operational state, and if there is a possibility that switching elements of the inverter may be over-heated, the frequency of the PWM controller is decreased by a frequency changing device, thereby preventing damage to the switching elements of the inverter due to the over-heating.