| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized and less-expensive ventilator by making a common application of a power source circuit between a solenoid and a control circuit.SOLUTION: This invention comprises a blower 109, a driving part 8 for driving the blower, a shutter 105 for opening or closing an aeration passage of the blower, a feed-back part 4 for outputting a duty A corresponding to a voltage A or a duty B corresponding to a voltage B lower than the voltage A, a DC-AC converting circuit 2 for converting AC voltage into DC voltage, a step-down part 3 for decreasing DC voltage outputted by the DC-AC converting circuit on the basis of a duty from a feed-back circuit, a solenoid 1 keeping the shutter to an opened state upon receiving voltage A and keeping the shutter to an opened state upon receiving voltage B, a delay part 5 starting a charging of capacitor upon inputting voltage A and outputting that the charging is finished upon elapsing a predetermined time, the feedback part outputs the duty A to the step-down part until it receives an output from the delay part that the charging is finished and outputs the duty B to the step-down part upon reception from the delay part that the charging is finished.SELECTED DRAWING: Figure 3 |
