Patent ID: 8027181

Claim:
A load drive device comprising: a DC power supply configured to allow an output voltage to be variably controlled; a drive circuit converting a DC voltage from said DC power supply into an AC voltage by a switching operation of a switching element to drive-control an electric load; a capacity element provided between said DC power supply and said drive circuit and smoothing the output voltage of said DC power supply for inputting to said drive circuit; and a control device controlling said DC power supply, said capacity element having a temperature dependence such that a resistance value of an equivalent series resistance increases with a decrease in temperature of said capacity element, and said control device setting an upper limit value of an input voltage of said drive circuit to a lower value depending on the decrease in the temperature of said capacity element, and, in response to a request from said electric load, setting the output voltage of said DC voltage to a value of less than the set upper limit value of said input voltage.