Electric power conversion systems – Cascaded or combined – diverse conversions in which the...
Reexamination Certificate
2005-12-08
2009-08-18
Ullah, Akm E (Department: 2858)
Electric power conversion systems
Cascaded or combined, diverse conversions in which the...
C323S283000, C323S284000
Reexamination Certificate
active
07577002
ABSTRACT:
A control circuit having frequency hopping capability is used for reducing the EMI of a power supply. A switching circuit is coupled to a feedback circuit to generate a switching signal for regulating an output of the power supply. A first oscillator determines the 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 reducing the EMI of the power supply. An output of the second oscillator controls the attenuation rate of the feedback signal of the feedback circuit. Therefore, even if the switching frequency is hopped, the output power and the output voltage can still be kept constant.
REFERENCES:
patent: 3971972 (1976-07-01), Stich
patent: 4190882 (1980-02-01), Chevalier et al.
patent: 4288675 (1981-09-01), Inoue
patent: 5661643 (1997-08-01), Blakely et al.
patent: 5686867 (1997-11-01), Sutardja et al.
patent: 5758271 (1998-05-01), Rich et al.
patent: 5889922 (1999-03-01), Bufe et al.
patent: 5892352 (1999-04-01), Kolar et al.
patent: 6127816 (2000-10-01), Hirst
patent: 6229366 (2001-05-01), Balakirshnan et al.
patent: 6249876 (2001-06-01), Balakrishnan et al.
patent: 6380813 (2002-04-01), Noumi et al.
patent: 7082293 (2006-07-01), Rofougaran et al.
patent: 2003/0072170 (2003-04-01), Yang et al.
patent: 2003/0112642 (2003-06-01), Wang
patent: 2005/0071114 (2005-03-01), Nehrig
M. Rahkala et al., “Effects of Switching Frequency Modulation on EMI performance of a Converter Using Spread Spectrum Approach” IEEE Transactions on Power Electronics, vol. 19, No. 2, Jan. 2002, pp. 93-99.
Feng Lin et al., “Reduction of Power Supply EMI Emission by Switching Frequency Modulation”, IEEE Transactions on Power Electronics, vol. 9, No. 1, Jan. 1994, pp. 132-137.
J.C. Patents
System General Corp.
Ullah Akm E
Williams Arun
LandOfFree
Frequency hopping control circuit for reducing EMI of power... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Frequency hopping control circuit for reducing EMI of power..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Frequency hopping control circuit for reducing EMI of power... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4097735