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:
Aug. 20, 1991
Filed:
Feb. 12, 1990
Antonius A Marinus, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A switched mode power supply circuit includes a controllable switch for controlling the current in the supply transformer of the power supply circuit. During normal operation of the power supply, its DC output voltage is maintained at a substantially constant, first value in spite of variations of the DC input voltage and of the load on the output voltage by controlling the duration of the conductivity time of the switch. A function generator supplies a signal, which is a given function of the output voltage, to a control input of a pulse duration modulator for determining the duration of the conductivity time. At an output voltage which is considerably lower than the first value, the signal of a starting circuit is passed on by a selection circuit to the said control input in order to increase the conductivity time of the switch. This signal corresponds to a shorter switch conductivity time than does the signal of the function generator. At the instant when the output voltage reaches the first value, the selection circuit blocks the passage of the start signal and passes on the signal of the function generator. The power supply thus provides a soft start with limited energy dissipation.