POWER SUPPLY VOLTAGE FLUCTUATION SUPPRESSION METHOD

摘要

PROBLEM TO BE SOLVED: To suppress sudden power supply voltage fluctuation without matching ON/OFF periods with each other regardless of the duty values of respective loads in the case of performing ON/OFF control in the prescribed control cycle of the plural loads requiring large power. SOLUTION: Detection signals from a temperature sensor are sampled immediately before a cycle set in each fixed period and a duty is computed. The computed duties of respective heaters are generally compared and respective ON timings and OFF timings are set so as not to match with each other. In the case that the duties of all the heaters are different, setting is performed so as to bring the center of respective ON time intervals to the center of the control cycle. Thus, not only the ON timings of the respective heaters but also the OFF timings are shifted timewise. Thus, the entire load current value of the heaters is increased stepwise and reduced stepwise.