Patent ID: 8823292

Claim:
An electric compressor comprising: an electric motor which operates said compressor; an external control unit which outputs commands for controlling the operation of said electric motor; and an inverter device which controls the operation of said electric motor which operates said compressor by commands from said external control unit provided with a drive circuit which uses an arithmetic logic unit to compute drive signals to said electric motor from said commands, a switching circuit which converts said drive signals to rotation control signals of said electric motor, and a cutoff circuit which cuts off input of said drive signals to said switching circuit at the time of an abnormality, said inverter device further comprising: a logic error detector which detects a logic error of the computed results of said drive signals at said arithmetic logic unit; and said logic error detector outputs an output cutoff signal to said cutoff circuit to cut off input of said drive signals to said switching circuit when there is a logic error in the computed results of said drive signals at said arithmetic logic unit.