| 摘要 |
PROBLEM TO BE SOLVED: To secure the minimum ON-widths, the minimum OFF-widths and, further, the non-lapping periods of outputted complementary PWM signals by a method in which cut-off timing control means which outputs a re-start signal to a minimum width securing means is provided. SOLUTION: A comparing circuit 3 outputs a comparison pulse Cu which is modulated by PWM to a minimum width securing circuit 4. The minimum width securing circuit 4 outputs a pulse signal Du whose minimum time is secured to a nonlapping circuit 5. On the other hand, the nonlapping circuit 5 secures the nonlapping periods of a P-signal and an N-signal which are complementary PWM signals. Further, in order to put a converter into a stationary state, the output of the PWM signal is cut-off by AND - circuits 7 and 8. Cut-off control signals Eup and Eun which control the permission of the outputs to the AND circuits 7 and 8 are outputted by a cut-off timing control circuit 6. The cut-off timing control circuit 6 controls mainly the timing for securing the minimum pulse width at the time of start or stop of the converter. |
