| 摘要 |
BATTERY FEED CIRCUIT A battery feed circuit where only a simple resistive feed is required to provide DC current to the load, e.g., telephone line and station set, because the part of the circuit which transmits and receives AC signals has an AC impedance that is negative. The circuit meets specified requirements for an AC termination impedance that is larger than the DC termination impedance because the negative AC impedance is connected in parallel with the resistive feed. The circuit achieves a substantial cost reduction with respect to prior art circuits because the DC feed part of the circuit has only passive components and because the telephone line is directly connected to only passive components in the AC part of the circuit, thereby reducing the cost of protection circuitry required.
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