| 摘要 |
PURPOSE:To contrive power saving, miniaturization an its cost down and to realize a good cooling efficiency with no waste of a driving gear having a fan for cooling a heat generating part. CONSTITUTION:A fan driving circuit 5 for driving a fan 4 by counter electromotive force generated in each coil while a motor 1 is driven and when electrification of the coils L1 to L5 is switched is provided. The fan can be driven without providing a power supply for exclusive use of the fan 4 separately from a power supply circuit 2 for driving the motor 1, and further the fan 4 is driven only when the motor 1 is driven. |
