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:
Jan. 29, 1991
Filed:
Apr. 18, 1989
Kazunobu Ohyama, Kusatsu, JP;
Hiroyuki Yamai, Kusatsu, JP;
Daikin Industries, Ltd., Osaka, JP;
Abstract
In a pulse-width modulation control unit for an inverter, in the case where the carrier frequency is a normal value of about 5 KHz, the control unit calculates the ON time (the PWM control pattern) at every calculation period corresponding to such a carrier frequency and divides the calculation ON time into plural pulses. This enables the control unit to present apparently such conditions that the PWM control was carried out at a higher carrier frequency (20 KHz or higher), while using a one-chip microcomputer which requires a comparatively long calculation time. Thus, the PWM control by a higher carrier frequency can be attained at a lower cost and by a simple circuit construction.