| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized power extraction apparatus which extracts power without noise by attenuating a data signal from a superimposed wave of power and the data signal. SOLUTION: A power extraction apparatus (1) is interposed on a feeder line for transmitting the superimposed wave of AC power of voltage of 30V or higher and current of 5A or higher and a data signal of frequency of 1 MHz or higher, and extracts power from which the data signal is removed by attenuating only the data signal to a predetermined attenuation amount. The power extraction apparatus (1) comprises a filter circuit (7), between a superimposed wave input terminal (2in) to which the superimposed wave is input and a power output terminal (2out) from which power is output, in which an attenuation starting frequency (f<SB>1</SB>) is set higher than the power frequency, an attenuation arriving frequency (f<SB>2</SB>) arriving the attenuation amount is set lower than the lower limit frequency of the data signal, and an attenuation rate from the attenuation starting frequency (f<SB>1</SB>) to the attenuation arriving frequency (f<SB>2</SB>) has low gradient characteristics of -2.5 to -12 dB/OCT. COPYRIGHT: (C)2008,JPO&INPIT
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