| 摘要 |
PURPOSE:To make continuous variation in characteristics while reducing parts in number by composing a circuit of two couples of common-emitter transistors and a couple of common-emitter and collector-connected transistors. CONSTITUTION:Among two couples of common-emitter transistors 15 and 16, and 17 and 18, transistors 15 and 18, and 16 and 17 are controlled by control voltages e1 and e2 respectively. Then, transistors 19 and 20 connected at collectors to the common emitters of those couples of transistors while capacitor 24 as an impedance element is connected to either of emitter resistances 22 and 23 are controlled by input voltage ea. This voltage control type gain circuit constitution requires only one capacity element and while output voltages differing in gain are developed across transistor 16 according to an input voltage frequency, gains of those output voltages are continuously controlled by control voltages e1 and e2. Therefore, a variable equalizer circuit of circuit constitution using a small number of impedance elements such as capacitors and easy to IC-implement can be realized which varies in characteristics continuously. |
