| 摘要 |
PROBLEM TO BE SOLVED: To provide a ventilation device having a simple circuit configuration and capable of assuring a desired ventilation air amount stably even if a voltage variation occurs at a commercial AC power source.SOLUTION: This invention comprises a primary side power supply circuit P1 for rectifying and smoothing a commercial AC power supply 11 to generate a primary side DC voltage HV; a secondary side power supply circuit P2 for generating secondary side DC voltages V02, V03; a ventilation fan 30; a DC motor 31; a rotation speed detection circuit 41; a constant current circuit 42; a voltage detection circuit 40 for detecting a variation of the primary side DC voltage HV; and a control device C arranged at the secondary side power supply circuit P2 to control the DC motor 31. The voltage detection circuit 40 transmits a variation of the primary side DC voltage HV to the secondary side power supply circuit P2 and inputs it into the control device C. The control device C controls a ventilation air amount on the basis of a rotation speed and a current of the DC motor 31, and the primary side DC voltage HV.SELECTED DRAWING: Figure 2 |
