POWER CONVERTER

摘要

Provided is a DC/DC power converter, which improves efficiency at a time of low output in addition to stability of high efficiency at a time of high output so as to achieve stable high efficiency characteristics. When an output voltage V2 is larger than a set voltage VS (ST2), the PWM width by the ON/OFF operation of a switch SW is increased (ST3), and the output is increased up to a PWM width maximum value Pmax (ST4, ST5). When the output voltage V2 becomes less than the set voltage VS (ST7), the PWM width is decreased (ST8), and it is determined whether or not this PWM width has reached a minimum value (Pmin) that minimizes the output efficiency (ST9). When the PWM width has reached the predetermined minimum value (Pmin) (ST11, ST12), the pulse width of the PWM width and the pulse width operation cycle are set to be predetermined multiplications of the pulse width prior to the change (ST13).