| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power unit for suppressing the fluctuations of the difference between a positive and a negative DC voltages which are generated simultaneously, resulting from ripples superposed on each DC voltage in particular. SOLUTION: In this switching power unit (10), a boosting converter (1P) applies a positive DC voltage (+VP) to the anode (PP) of the EL panel (P), while a reverse converter (1N) applies a negative DC voltage (-VN) to the cathode (PN). A feedback part (2) generates error signals EP, EN based on the positive and negative DC voltages (+VP, -VN) and positive and negative reference voltages (+VrP, -VrN). A PWM control unit (3) converts two error signals (EP, EN) to two control signals (SP, SN), allowing one active period to be stored in the other inactive period or one inactive period to be stored in the other active period between the two control signals (SP, SN) in particular. The two converters (1P, 1N) receive the negative feedback by the two control signals (SP, SN). COPYRIGHT: (C)2007,JPO&INPIT
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