| 摘要 |
PROBLEM TO BE SOLVED: To provide a power factor compensation circuit of an inverter system which is simple in circuit configuration and allows semiconductor manufacturing processes to be simplified and manufacturing cost to be reduced, and also provide its method. SOLUTION: An inverter system consists of a rectification section 61, a choke coil 62, a capacitor 63 for smoothing, and an inverter 64. A power factor compensation circuit of this inverter system is provided with a switching element Q1 for controlling a charging/discharging operation of a capacitor 63 for smoothing according to a switching signal, a zero voltage detection section 65 which outputs a zero voltage detection signal, a frequency judgement section 70 which outputs a frequency judgement signal, a voltage level detection section 67 for detecting the voltage across the capacitor 63 for smoothing, a ROM 66 which stores the data with respect to a sine wave of the input supply voltage, a controlling section 68 which adjusts the cycle according to the frequency of the input power judged by the frequency judgement section 70 and outputs the adjusted cycle, and a driving section 69 which controls the on/off of the switching element Q1. |
