| 摘要 |
PURPOSE:To enable a telephone to fulfill its function sufficiently, even if line conditions are unfavorable, by decreasing a voltage drop in a rectifier circuit by the use of a transistor in place of a diode. CONSTITUTION:If a transmitter for telephone 1 is lifted and a transistor 6 is turned ON, only a speaking circuit will be connected with a DC output side of bridge rectifier circuit 2. At that time, a bias current flows through transistors Tr1P and Tr1N and both transistors are turned ON. If a polarity between circuit terminals are reversed, a bias current flows through transistors Tr2P and Tr2N and both transistors are turned ON.
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