| 摘要 |
<p>PURPOSE:To facilitate the packaging in a one-chip IC with the smallness of capacity contrived for a capacitor in a PWM control circuit by performing a combined control of a chopper in both its on-off duty ratio and frequency, thereby controlling a rate of conduction of a field current. CONSTITUTION:A charging generator 1 applies a variable frequency system to its field current control using a frequency variable-type PWM control means 52 of a field current, thereby controlling chopper 53 controlled in its frequency corresponding to a duty alpha and in the frequency (f) to a secondary function alpha(1-alpha) of the duty alpha. In case of generating a PWM waveform by a feedback of output voltage to an input in a circuit of the PWM control means 52, by the feedback of output voltage, divided, to the input, a PWM generating circuit can attain the smallness in its capacitance value and resistance value. Thus, a control circuit easily attains its IC packaging.</p> |
