| 摘要 |
PROBLEM TO BE SOLVED: To provide communication equipment for a telephone line that does not receive a harmful effect even under a high voltage to be supplied to a telephone line. SOLUTION: As long as the output voltage of a rectifier circuit rectifying the current of the telephone line does not surpass a prescribed high voltage, this communication equipment has a switching circuit that relays the output voltage of the rectifier circuit to a communicating part. The switching circuit includes a transistor and a conduction circuit which is connected to the base electrode of the transistor, controls the conduction between the emitter and the collector and makes conduction performed between the rectifier circuit and a communicating part.
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