| 摘要 |
PURPOSE:To prevent unnecessary oscillation and effect of output due to an external radio wave by grounding an emitter of a transistor (TR) to the base of which an input signal and a bias voltage are applied and connecting the collector to the mitter of a TR for amplifier of the next stage. CONSTITUTION:The base of a TRQ1 is connected to an input terminal 1 and the emitter of the TRQ1 is grounded. The emitter of a TRQ3 is connected to the collector of the TRQ1 through a resistor R3. The collector of a TRQ2 is connected to a power supply VCC through a resistor R1, and a bias voltage is applied to the base of the TRQ2 through a resistor R2 and diodes D1-D3. A signal appearing at the collector of the TRQ2 is outputted to an output terminal 2 via an amplifier circuit 3. Further, an output of the circuit 3 is fed to the base of the TRQ1 via a bias circuit 4. Thus, unnecessary oscillation and the effect of output due to an external radio wave are prevented in this way. |
