| 摘要 |
PROBLEM TO BE SOLVED: To provide a power source frequency determining device for an inexpensive air-conditioner of simple structure capable of reducing a size of a wiring board. SOLUTION: This power source frequency determining device comprises a current transformer 4 for converting the voltage of a commercial power source 3 into low voltage, a rectification circuit 5 for rectifying a voltage signal from the current transformer 4, and a microcomputer 6 receiving a signal from the rectification circuit 5 and determining the frequency of the commercial power source 3. As the current transformer 4 converts the voltage of the commercial power source 4 into low voltage, an insulation distance of the wiring for determining the power source frequency on a printed wiring board can be reduced. The microcomputer 6 receives the signal from the rectification circuit 5 at its control port 9 through a smoothing circuit 7, and performs the load control and the like. COPYRIGHT: (C)2004,JPO
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