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. 06, 2009
Filed:
Feb. 28, 2007
Hideo Ishii, Osaka, JP;
Toru Arai, Osaka, JP;
Hideo Ishii, Osaka, JP;
Toru Arai, Osaka, JP;
Sansha Electric Manufacturing Company Limited, Osaka-shi-, Osaka-fu, JP;
Abstract
A power supply unit includes an input-side rectifying circuit (), an inverter () and an output-side rectifying circuit (), which include power semiconductor devices. The power supply unit is powered during a powering period, and the powering is interrupted during a pausing period. The powering and pausing periods alternate. A fan () is driven during each powering period to cool the power semiconductor devices. A temperature detector () measures the temperature of the power semiconductor devices and develops a measured-temperature representative signal. A setter () produces a reference value, which decreases over the pausing period from the measured-temperature representative signal at the beginning of the pausing period to an intended-temperature representative signal representing the temperature to be attained by the power semiconductor devices at the end of the pausing period. The reference value is prepared from the measured-temperature representative signal at the beginning of the pausing period, the intended-temperature representative signal, and the length of the pausing period. An error amplifier () and a fan control unit () control the rotation rate of the fan () to make the measured-temperature representative signal track the reference value.