Electric power conversion systems – Current conversion – With means to introduce or eliminate frequency components
Reexamination Certificate
2005-11-08
2009-02-10
Ullah, Akm E (Department: 2838)
Electric power conversion systems
Current conversion
With means to introduce or eliminate frequency components
C363S039000, C363S021130, C363S021170
Reexamination Certificate
active
07489529
ABSTRACT:
A control circuit having frequency modulation is used for reducing the EMI of a power converter. A switching circuit is couple to a feedback circuit to generate a switching signal for regulating an output of the power converter. A first oscillator is equipped to determine a switching frequency of the switching signal. A second oscillator is coupled to the first oscillator to modulate the switching frequency of the switching signal for reduce the EMI of the power converter. A programmable resistor is designed to attenuate the feedback signal of the feedback circuit. The resistance of the programmable resistor is controlled by the output of the second oscillator. Therefore, the output power and the output voltage can be kept constant when the switching frequency is modulated.
REFERENCES:
patent: 3971972 (1976-07-01), Stich
patent: 6014063 (2000-01-01), Liu et al.
patent: 6229366 (2001-05-01), Balakirshnan et al.
patent: 6249876 (2001-06-01), Balakrishnan et al.
patent: 7061780 (2006-06-01), Yang et al.
“Reduction of Power Supply EMI Emission by Switching Frequency Modulation” Feng Lin et al. / IEEE Transactions on Power Electronics, vol. 9, No. 1, Jan. 1994 / pp. 132-137.
“Effects of Switching Frequency Modulation on EMI Performance of a Converter Using Spread Spectrum Approach” M. Rahkala et al. / Applied Power Electronics Conference and Exposition, 2002, 17-Annual, IEEE, vol. 1 / pp. 93-99.
J.C. Patents
System General Corp.
Tran Nguyen
Ullah Akm E
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