| 摘要 |
PURPOSE:To obtain an output of different characteristics, by applying a common gain control voltage to two different differential amplifiers and giving a common signal to a current control element provided at the emitter. CONSTITUTION:When a signal is applied to an input signal applying terminal 5, a current including tis signal component flows as the collector current of transistors (TR) 8, 9. In this case, when a voltage VC of a variable DC power supply 10 is zero, TRs 1, 3 are interrupted and no output is produced. When the relation of V1>V2 is in existence between the voltages V1, V2 of DC power supplies 11, 12, a Vc is increased. When Vc=V2, equal current flows to TRs 3, 4. When the Vc is increased further, the TR3 is conductive and the TR4 is non-conductive. At Vc=V1, an equal current flows to the TRs 1, 2. As a result, the relation between the Vc and the output can be made to poligonal line characteristics. |
