Colpitts Oscillator Diagram. The circuit diagram of a typical colpitts oscillator using transistor is shown in the figure below. It can be realized by using gain device such as bipolar junction transistor bjt operational amplifier and field effect transistor fet as similar in other lc oscillators also.
Resistors r d r s and r g are polarization resistors. Resistor r4 limits the collector current of the transistor. Cin is the input dc decoupling capacitor while cout is the output decoupling capacitor.
A simple diagram of a colpitts oscillator using a field effect transistor is schematically presented in figure 3 48.
The resistors r 1 r 2 and r e provide necessary bias condition for the circuit. Ground thereby providing any signal degeneration. A colpitts oscillator is the electrical dual of a hartley oscillator where the feedback signal is taken from an inductive voltage divider consisting of two coils in series or a tapped coil. Many oscillator circuits that produce sinusoidal waveforms use an lc resonance circuit except some electronic circuits such as rc oscillations crystal oscillators and few other oscillators don t require additional inductances.
