| 摘要 |
PURPOSE:To obtain an excellent sound volume output characteristics in an aural point of view and to the variation of the control DC voltage, by using a differential amplifying circuit in which the emitters have a common connection with the input signal applied to the point of common connection. CONSTITUTION:As the input signal 21 is applied to the base of the transistor 17, the collector current of the transistor 17 contains a signal. This current flows to the emitters of transistors 13 and 14, and the base potential difference between transistors 13 and 14 can be expressed as IXR8 from the resistance 8 and the current I flowing to said resistance. This potential difference is varied to change the distribution ratio of the collector current of transistor 17 to the emitter current between transistors 13 and 14. Thus the current flowing to the collector of transistor 14 flows to the load resistance 15 according to the above-mentioned potential difference to produce an output signal at the output terminal 24. |
