| 摘要 |
PURPOSE:To make the adjusting work easy, by using a variable gain amplifier in which the relation between an input (x) and an output (y) is expressed with a specific equation to the control input uC. CONSTITUTION:A gain control amplifier 13 is inserted and connected between an input terminal 11 and an output terminal 12. In the gain control type amplifier 13, the relation between the input (x) and the output (y) is expressed as the equation to the control voltage vC. Further, another end of the addition resistor 14 connected to the input terminal 11 and the addition resistor 15 connected to the output terminal 12 is commonly connected, and the addition circuit picking up the addition output of input (x) and output (y) from the common connection point is constituted. After this addition output is amplified at an amplifier 16, it becomes the control input voltage uC via a logarithmic conversion circuit 18, rectifying and smooth circuit 19, and amplifier 20 and it is fed to the control terminal of the variable gain type amplifier 13. |
