This is a Colpitts oscillator, an oscillator that uses an LC circuit combined with a transistor for feedback. The Colpitts oscillator (capacitive three-point), named after its inventor Edwin Colpitts, is one of many electronic oscillator circuits that use a combination of an inductor (L) with a capacitor (C) to determine the frequency; it is also called an LC oscillator. One of the key features of oscillators of this kind is their simplicity (only a single inductor without taps is needed). The feedback voltage is taken from a capacitive voltage divider. If the transistor is removed, the inductor and the two capacitors form a resonant circuit, as in the LRC example. Current moves back and forth as the capacitors charge and discharge through the inductor. The transistor amplifies this oscillation and keeps it from dying out. The transistor cannot conduct until C1 is charged to about 680 mV. When the transistor is off, the output voltage is about 4.5 V. Current from the 1 kΩ resistor and the inductor charges C2. The current through the inductor slows and then reverses, charging C1 again. When it is charged, the transistor conducts current, lowering the output level. As the oscillation continues, the transistor turns off again. The current through the 1 kΩ resistor sustains the oscillation.
This page is a utility for simulating генератор колпитца online with specified initial values.
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