| 摘要 |
PURPOSE:To adjust properly the effect of separation control and high cut control without giving effect on the time constant by providing a DC voltage control circuit changing optionally the ratio of a multi-path disturbance quantity to an S meter control voltage. CONSTITUTION:If multi-path disturbance takes place, a ripple component super imposed on an S meter voltage is converted into a current I1 by a voltage- current converting circuit 16 and the current is compared with a reference current I0 by a current comparison circuit 17. The current difference (I1-I0) becomes a multi-path current. The current becomes a reference current of a current mirror circuit 18 comprising transistors (TRs) Q3, Q4 to produce a mirror current In (=R3(I1-I0)/R4). The current In decrease the base potential of a TR Q2 by InR4 and the output voltage is decreased similarly by the drop InR4. The current value In is controlled by the ratio of resistors R5, R6 and the output voltage is changed optionally by changing the resistance ratio. In this case, the time constant is decided by a constant current I3 and a capacitor C5 and no effect is given on the time constant by changing the resistance ratio to change the voltage drop.
|
