| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot air heater having improved safety by driving a motor for a preset time even after the DC inverter motor driven with constant drive control is constrained to achieve active equipment cooling operation. SOLUTION: A control circuit 20 controls motor voltage when the number of revolutions of a blowing fan 11 is 200 or more in driving the fan motor 12, so that a detected number of revolutions gets to a preset target number. When the number is less than 200, fixed voltage is applied to the motor to limit power supply. Even in circumstances that the revolution number is not obtained by the constraint of the blowing fan 11, resulting in an increased load current in the fan motor 12, the heat of the fan motor 12 is suppressed by limiting the power supply. COPYRIGHT: (C)2004,JPO
|
