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:
Jun. 12, 2001
Filed:
May. 16, 2000
Hiroshi Yamazaki, Nagano, JP;
Nagano Japan Radio Co., Ltd., Nagano, JP;
Abstract
A switching power supply includes a power factor improvement converter circuit, a main switching circuit for generating output voltage from a DC voltage generated by the power factor improvement converter circuit, two control ICs for controlling the dual converter circuits, respectively, two capacitors for supplying current to the two control ICs, respectively, and at least one start-up circuit for controlling start-up of the two control ICs. The switching power supply includes an auxiliary power supply circuit for charging one of the capacitors with the DC voltage generated by the power factor improvement converter circuit, and the at least one start-up circuit is a single start-up circuit which includes one charging device formed by current-limiting resistors for charging the other capacitor, a Zener diode and a diode forming a unidirectional element via which energy stored in the one capacitor is supplied to the other capacitor when a charging voltage of the one capacitor is higher than a charging voltage of the other capacitor by a voltage equal to or higher than a predetermined voltage, and another charging device formed by a current-limiting resistor and a switching element for charging the one capacitor with the DC voltage generated by the power factor improvement converter circuit.