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单词 Wien bridge oscillator
释义

Wien bridge oscillator

中文百科

文氏电桥

Esquema de un oscilador de Puente de Wien en el cual Rb es una pequeña lámpara incandescente. Generalmente, R1=R2=R y C1=C2=C. En condiciones normales, la lámpara se calienta hasta que su resistencia es igual a Rf/2.
Schematic of a Wien bridge oscillator that uses diodes to control amplitude.  This circuit typically produces total harmonic distortion in the range of 1-5% depending on how carefully it is trimmed.

文氏电桥英语:Wien bridge oscillator)是利用电阻与电容作为回授的一种电桥型振荡器,工作频率可达约几MHz左右。将输出接至一电阻(R_3)与电容(C_1)串联之电抗(X_s)串接一电阻(R_4)与电容(C_2)并联之电抗(X_p),再将X_p之电压回授至输入端,此方式称为韦恩桥式震荡器或韦恩桥式震荡电路。


X_s  = R_4 -j X_{C1}

X_p  = R_3 // j X_{C2} = {R_3 \cdot -jX_{C2} \over R_3 -jX_{C2}}

回授电路如下:


\beta(s) = {X_p \over { X_s + X_p}  }

={ R_3 \cdot -jX_{C2} \over { (R_4 -j X_{c1}) \cdot (R_3 -jX_{C2}) + R_3 \cdot -jX_{C2} } }

={ R_3 X_{C2}  \over ( R_4 X_{C2} + R_3 X_{C1} +R_3 X_{C2}  ) +j(R_3 R_4 -X_{C1}X_{C2})}

利用巴克豪生准则,震荡时虚部为零,增益为1。

故虚部之R_3 R_4 -X_{C1}X_{C2}=0
回路增益\beta A = { R_3 X_{C2}  \over ( R_4 X_{C2} + R_3 X_{C1} +R_3 X_{C2}  ) }\cdot A = 1

R_3 = R_4 = R X_{C1} = X_{C2}=X

\beta = {1 \over 3}

增益必须为  A = 3始可满足振荡之要求。

英语百科

Wien bridge oscillator 文氏电桥

In this version of the oscillator, Rb is a small incandescent lamp. Usually R1 = R2 = R and C1 = C2 = C. In normal operation, Rb self heats to the point where its resistance is Rf/2.
Schematic of a Wien bridge oscillator that uses diodes to control amplitude.  This circuit typically produces total harmonic distortion in the range of 1-5% depending on how carefully it is trimmed.
Simplified schematic of a Meacham's bridge oscillator published in Bell System Technical Journal, Oct 1938. Unmarked capacitors have enough capacitance to be considered short circuits at signal frequency. Unmarked resistors and inductor are considered to be appropriate values for biasing and loading the vacuum tube. Node labels in this figure are not present in the publication.
Simplified schematic of a Wien bridge oscillator from Hewlett’s US patent 2,268,873.  Unmarked capacitors have enough capacitance to be considered short circuits at signal frequency.  Unmarked resistors are considered to be appropriate values for biasing and loading the vacuum tubes.  Node labels and reference designators in this figure are not the same as used in the patent.  The vacuum tubes indicated in Hewlett's patent were pentodes rather than the triodes shown here.

A Wien bridge oscillator is a type of electronic oscillator that generates sine waves. It can generate a large range of frequencies. The oscillator is based on a bridge circuit originally developed by Max Wien in 1891 for the measurement of impedances. The bridge comprises four resistors and two capacitors. The oscillator can also be viewed as a positive gain amplifier combined with a bandpass filter that provides positive feedback. Automatic gain control, intentional non-linearity and incidental non-linearity limit the output amplitude in various implementations of the oscillator.

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更新时间:2025/6/23 4:58:08