The drive circuit 37 and the control circuit 38 will now be described below. The drive circuit 37 and the control circuit 38 are disposed on the second surface 48 of the circuit board 33. The drive circuit 37 is a circuit configured to convert direct current power into alternating current power to supply the alternating current power to the electric motor 13. The drive circuit 37 includes a plurality of switching elements for converting the direct current power into the alternating current power. The control circuit 38 is a circuit configured to control the drive circuit 37. The control circuit 38 includes a microprocessor configured to operate according to a program. The microprocessor includes a central processing unit configured to perform arithmetic operations and a memory configured to store the program. The control circuit 38 is configured to control the drive circuit 37 in response to a command from an electronic control unit of the air conditioning system. For the sake of simplification, the drive circuit 37 and the control circuit 38 are illustrated as rectangles in FIG. 3.