positive feedback
Quick Summary
In electronics, positive feedback is a process where a feedback signal reinforces the original signal, leading to an increase in output. This can cause an amplifier to oscillate, generating an alternating current (AC) signal.12
Oscillator circuits utilize positive feedback to create these signals, which are essential for many electronic devices like radios and electronic watches. In a tunable oscillator, a tuned circuit (combining an inductor and capacitor) resonates at a specific frequency. Positive feedback, often provided by an inductor, amplifies signals at this resonant frequency, causing the circuit to oscillate.2
Quartz crystals are also used in oscillators for precise frequency control, especially in electronic watches. The piezoelectric effect of quartz allows it to vibrate at a high frequency when an electric field is applied. Positive feedback provides energy to sustain these vibrations, ensuring a stable output frequency.2
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