To provide a power unit for a vehicle, which can suppress voltage variation on an input side, even if the current on the output side of a voltage converting means suddenly changes.
The power unit for a vehicle is equipped with a DC-DC converter 30 for voltage converting the input side power to supply it to an output side on-vehicle load 24, a current detector 54 for detecting the output side current of the DC-DC converter 30, and a current limiting circuit 50 and a PWM control circuit 38 which can suppress the variation on the input side voltage by varying the output side current below the specified variation speed, when the current value on the output side current detected by the current detector 54 reaches a specified current threshold value.
HARA AKIHIRO
OSHIMA YOSHIAKI
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