| 摘要 |
PURPOSE:To suppress the occurrence of vibration sound of a fan motor by phase control while making the most use of the strong point of the phase control enough, concerning the revolution control of the fan motor. CONSTITUTION:This is an air flow rate controller for a hot air type heater which controls the revolution of a fan motor 6 by controlling the phase of the voltage of a fan motor power source circuit 5, and has relays 9a and 9b and a microcomputer 4 for controlling the relays, in addition to phase control means 7, 10, and 4. A voltage drop means 9a, 9b, 11, and 4 are provided, which connect a fixed resistor 8 to the fan motor power source circuit 5 in series in case of setting the revolution of the fan motor to the lower revolution below a certain value. |
