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:
Jul. 09, 2002
Filed:
Jul. 20, 2000
Gregory D. Brink, Port Townsend, WA (US);
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A system and method for charging a high-voltage capacitor through the application of current having magnitude that has a fixed frequency waveform. During a charging sequence in which the current is applied to the capacitor, the duty cycle of the fixed frequency current waveform is dynamically controlled based on the voltage state of the capacitor to modify the energy transfer according to the efficiency with which energy can be delivered to the capacitor. This optimizes the capacitor charging sequence, increasing the speed with which the high voltage capacitor is charged. Generally, energy is transferred from a power source to the capacitor via a magnetic element such as a fly-back transformer. A pulsed voltage supply provides voltage pulses having a constant frequency and an adjustable duty cycle to a primary winding of the transformer. Initially, there is no energy stored in the transformer core. As a result, the duty cycle of the initial voltage pulse is of sufficient duration to accumulate stored energy in the transformer core. Once a predetermined quantity of energy is stored in the transformer, the transformer is controlled to generate a current to charge the capacitor. The magnitude of the current has a fixed frequency and variable duty cycle waveform.