| 摘要 |
PURPOSE:To eliminate the need for an operational amplifier used exclusively for limiter level setting and to set an optimum limit level by inserting and connecting an amplitude limiting circuit to a prescribed position. CONSTITUTION:The output of a high-pass filter 26 of variable cutoff frequency is sent to the inverted input terminal of the operational amplifier 25 as an adding means through a voltage-current converter 33 and a resistance 34. A feedback resistance 35 is connected between the inverted input terminal and the output terminal 22 of the amplifier 25, and the amplitude limiting circuit 28 is inserted between the output terminal of the converter 33 and the output terminal 22. The uninverted input terminal of the amplifier 25 connects with a main signal line 23. Thus, the circuit is formed to eliminate the need for an operational amplifier used exclusively for limiter level setting. Further, resistance values of resistances 34 and 35 are selected to set an optimum limit level. |
