| 摘要 |
PROBLEM TO BE SOLVED: To provide a warm-air heater where, when half-waves of power supply frequency are applied to the drive motor of an air blower to effect deceleration and stop, an excessive current to the driving motor, abnormal noise from the drive motor, and the like are suppressed and the generation of excessive current to a power transformer which supplies power to the drive motor and abnormal noise from the power transformer are also suppressed. SOLUTION: Half-waves of power supply frequency applied as brake to the drive motor are subjected to phase control and wave-omitting control where some of half-waves are omitted. Thereby, power to the drive motor and the power transformer which supplies power to the drive motor is reduced. As a result, abnormal noise is suppressed and harmful effects, such as heating, are improved.
|
