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. 27, 2001
Filed:
Jun. 22, 2000
TDK Corporation, Tokyo, JP;
Abstract
This PWM inverter apparatus includes a first and second current control type semiconductor switching elements connected in series which are connected in parallel to a DC power supply. An output is generated by alternately switching the first and second semiconductor switching elements. Resistive semiconductor switching elements having a higher switching speed than the first and second semiconductor switching elements and a resistance-to-current characteristics producing a voltage drop are respectively connected in parallel to respective the first and second semiconductor switching elements. In a half cycle of an alternating output current, while the output current is higher than a predetermined rate with respect to a peak current, a switching timing is controlled to produce a switching control signal to the resistive semiconductor switching elements ahead of a switching control signal to the first and second semiconductor switching elements, and to terminate the switching control signal to the resistive semiconductor switching elements at a time when a predetermined period passes after the switching control signal given to the first and second semiconductor switching elements has been terminated. In the half cycle of the alternating output current, while the output current is lower than the predetermined rate with respect to the peak current, the switching timing is controlled to generate the output by the switching operation only of the resistive semiconductor switching elements.