| 摘要 |
PROBLEM TO BE SOLVED: To reduce effects of noise on PFC control circuits by reducing the occurrence frequency of timings of overlapping on/off changes in two switching signals generated by PWM modulation of carrier signals.SOLUTION: A DC power supply device includes: a rectifier 2 for rectifying an input of an AC power supply 1; a smoothing capacitor 7; two switching sections 3, 4 having input ends 3e, 4e, output ends 3f, 4f and common ends 3g, 4g; a carrier oscillation section 5 for outputting two carrier signals; and a PFC control section 9 for outputting switching signals resulting from PWM modulation of the carrier signals input thereinto to the switching sections, respectively. Specifically, the carrier oscillation section 5 can change the frequencies of the carrier signals independently, and when increasing the frequency of one carrier signal, lowers the frequency of the other carrier signal. |
