Bilingual edition: English is preserved and Chinese follows each unit. Terminology uses the confirmed v20260916 glossary; automated semantic review remains traceable.
中英双语版：英文原文完整保留，中文紧随对应单元；术语采用 v20260916 确认表，自动语义审校结果可追溯。

Positive Feedback

正反馈

The use of positive feedback is useful for producing oscillators. The condition for positive feedback is that a portion of the output is combined in phase with the input. For an amplifer with positive feedback the gain is given by the expression below.

使用正反馈有助于产生振荡器。正反馈的条件是输出的一部分与输入信号同相。对于具有正反馈的放大器，其增益由下式给出。
The large open loop gain of an op-amp makes it inevitable that the condition

will be reached, and the gain expression

将被达到，并且增益表达式

becomes infinite.

变得无限大。
运算放大器的高开环增益使其不可避免地满足条件
Practically speaking, the gain which applies at low signal amplitudes will be reduced until the output amplitude reaches some constant value. However, that limiting value will be independent of input, allowing the circuit to produce a designed output.

实际上，在低信号幅度下适用的增益会随着输出幅度增加而减小，直到输出幅度达到某个恒定值。然而，这个极限值与输入无关，使得电路能够产生设计好的输出。
 Index

Electronics concepts

Op-amp concepts

Feedback concepts
索引 电子概念 运算放大器概念 反馈概念
 
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Op-Amp Oscillators

运算放大器振荡器
Phase-Shift Oscillator
相位移振荡器
Colpitts Oscillator
科尔皮特振荡器
Square-wave generator
方波发生器


Other Oscillators
其他振荡器
 Index

Electronics concepts

Op-amp concepts
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Colpitts Oscillator

科尔皮特振荡器
The Colpitts oscillator achieves positive feedback by using an inverting amplifier plus the 180° phase shift across a parallel resonant circuit. The series capacitors combine to produce
so the resonant frequency is
科尔皮特振荡器通过使用反相放大器和并联谐振电路中的180°相位移来实现正反馈。串联电容器组合产生所以谐振频率是

For component values

分量值
Capacitor C1 = mF
Capacitor C2 = mF
Inductor L = mH

the frequency is f = kHz = MHz = x10^ Hz

Calculation notes: If component values are changed, the new frequency will be calculated. If a frequency is entered, then you must click on the active component name of the component you wish to calculate to force the frequency to match the entered value.

计算说明：如果组件值发生变化，将重新计算新的频率。如果已输入频率，则必须点击您希望计算的组件的活动组件名称以强制频率与输入的值匹配。
Other Oscillators
其他振荡器
电容器 C₁ = mF 电容器 C₂ = mF 电感器 L = mH 频率是 f = kHz = MHz = x10⁴ Hz
中文译文中的待填/计算数值依次对应：1：c1 2：c2 3：L 4：fk 5：fm 6：fb 7：fp。实际数值以上方原输入框为准。
 Index

Electronics concepts

Op-amp concepts
索引 电子学概念 运算放大器概念
 
HyperPhysics*****Electricity and magnetism
HyperPhysics ***** 电磁学
R Nave
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