To provide a motor driving device that keeps a motor control function enabled even when a main power source is at a stop and makes it possible to reduce the wasteful power consumption of a fan motor and improve its life.
The motor driving device is so constructed that a main power supply input portion 3 consisting of a rectifier circuit 3a and a smoothing circuit 3b and a control power supply input portion 6 are separated from each other. The motor driving device includes: a fan power supply generation circuit 9 that generates power supply for a cooling fan from the main power supply input portion 3; an AC fan motor 8 that is driven by power supply generated by the fan power supply generation circuit 9; a control circuit 7 that operates on the output of the control power supply input portion 6; and a motor drive circuit 4 that is inputted with the output of the main power supply input portion 3 and a signal from the control circuit 7.
NAKANO SHIGERU
Tomoyasu Sakaguchi
Hiroki Naito