| 摘要 |
PURPOSE:To improve the function of a non-linear emphasizing circuit, by changing optionally the level of amplitude control voltage while maintaining the amplitude limiting function as it is. CONSTITUTION:The input signal applied to an input terminal 1 is referred to as Vi, the output signal of a transmitting circuit 2 is V1 with no connection of a non-linear element 3, and the output impedance of the circuit 2 is Z respectively. Then the signal V0 delivered to an output terminal 26 of a differential amplifier 23 is set at -KV1, and the voltage (K+1)V1 is generated between the output terminal of the circuit 2 and the terminal 26. Therefore when the element 3 is connected between the output terminal of the circuit 2 and the terminal 26, the voltage V1 is delivered to an output terminal 4 in case the amplitude of (K+1)V1 is less than the amplitude limiting voltage VL which is proper to the element 3. The impedance of the element 3 decreases in the case of (K+1)V1> VL, and the amplitude is limited to VL(K+1) for the signal which is delivered to the terminal 4. Furthermore an optional amplitude limiting level is obtained by varying the ratio between resistances R38 and R39. |
