| 摘要 |
PURPOSE:To prevent an unnecessary overshoot in a transition period by setting a value corresponding to a target-voltage set value and providing a voltage control means controlling the drive-pulse width set information of a switching element so as to be gradually varied and be changed into the target voltage. CONSTITUTION:In a CPU 1, a transformer T14 output is rectified and a power supply Vs is connected to the analog input terminal ADCO of the CPU 1 through a power supply detecting section 5, and the CPU is loop-controlled. Voltage input to the analog input terminal ADCO is input to a comparator in the CPU 1. The voltage is compared with an output from a D/A converter as a reference power supply in the comparator, and the result of comparison is latched as the HIGH/LOW signal of a digital binary. The signal is input to a pulse-width modulation circuit, and the up and down of a count value for determining output pulse width are conducted by the result of the comparator changed into a digital binary signal, thus altering output pulse width. The variation of output pulse width is changed being synchronized with a specified internal clock. |
