| 摘要 |
PURPOSE:To control average voltage bearing on a load in good order and at high precision, by selectively using two different pulse modulation systems according to the degree of command voltage. CONSTITUTION:The output of a comparator 50 with hysteresis having the hysteresis width of + or - V and executing 2-input comparison is applied to a driving circuit 10. When command voltage Vr is set in a specified area like the roughly intermediate area of average voltage bearing on a load, the comparator 50 fixes the cycle of pulse and modulates the ON/OFF duty cycle according to the command voltage Vr. When the command voltage Vr is set so that the average voltage bearing on the load may exceed the intermediate area and may get higher or lower, then an OFF-period or an ON-period is fixed, and the pulse cycle is modulated according to the command voltage Vr. |
