Electric power conversion systems – Current conversion – Including d.c.-a.c.-d.c. converter
Reexamination Certificate
2011-07-05
2011-07-05
Berhane, Adolf (Department: 2838)
Electric power conversion systems
Current conversion
Including d.c.-a.c.-d.c. converter
C363S021080, C363S021160, C363S021120
Reexamination Certificate
active
07974107
ABSTRACT:
A hybrid constant current control system that uses both pulse width modulation (PWM) and pulse frequency modulation (PFM) control. When transitioning from constant voltage mode to constant current mode the present invention can continue to control using PWM. Thereafter, when the voltage has dropped, the present invention smoothly transitions to PFM mode. The point of transition is based upon the switching frequency and the lowest rated voltage of operation. The system and method avoids very short (narrow) Ton times which ensures accurate constant current (CC) control with bipolar junction transistor (BJT) devices. The present invention also avoids acoustic noise because the switching frequency is maintained at a high enough level to avoid such acoustic noise even when the energy transferred through the transformer is still substantial and the output voltage is not too low. In addition the output current limit is insensitive to variation in the inductance-input voltage ratio, and is minimized against leakage inductance.
REFERENCES:
patent: 4800328 (1989-01-01), Bolger et al.
patent: 7492619 (2009-02-01), Ye et al.
patent: 2005/0162874 (2005-07-01), Umetsu
patent: 2007/0164720 (2007-07-01), Lalithambika et al.
patent: 2008/0259652 (2008-10-01), Huynh et al.
patent: 2010/0046258 (2010-02-01), Coulson et al.
PCT International Search Report and Written Opinion, PCT/US08/74457, Nov. 3, 2008, 8 Pages.
Kesterson John
Li Yong
Wang Xiao Yan
Yan Liang
Zheng Junjie
Berhane Adolf
Fenwick & West LLP
iWatt Inc.
Tran Nguyen
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