Table of Contents
What is the difference between Hartley and Colpitts oscillator?
Thus the main difference between a Colpitts Oscillator and a Hartley Oscillator is that the former uses tapped capacitance, while the latter uses tapped inductance.
How does Colpitts oscillator works?
Colpitts oscillator works with a combination of inductors and capacitors by forming an LC filter. Same as other oscillators Colpitts oscillator consists of a gain device, and the output is connected with an LC circuit feedback loop. The Colpitts oscillator is a linear oscillator which produces a sinusoidal waveform.
What are the advantages of Colpitts oscillator over Hartley?
The advantages of the Colpitts Oscillator over the Hartley oscillators are that the Colpitts oscillator produces a more purer sinusoidal waveform due to the low impedance paths of the capacitors at high frequencies.
What is meant by Colpitts oscillator?
A Colpitts oscillator, invented in 1918 by American engineer Edwin H. Colpitts, is one of a number of designs for LC oscillators, electronic oscillators that use a combination of inductors (L) and capacitors (C) to produce an oscillation at a certain frequency.
Which type of feedback is used in oscillator?
positive feedback
The feedback that is used in an oscillator is positive feedback. The oscillator which acts as an amplifier makes use of positive feedback to generate an output frequency.
What is Barkhausen principle?
Principle of Oscillator and Barkhausen Criterion The principle of the oscillator is that when the feedback factor or the loop gain is one, then the overall gain of the oscillator circuit will be infinite. This implies that even when there is no input then also the oscillator will continue to generate the output.
What is bar cushion criteria?
The circuit will oscillate when two conditions, called Barkhausen’s criteria are met. These two conditions are: The loop gain must be unity or greater. The feedback signal feeding back at the input must be phase-shifted by 360° (which is the same as zero degrees).
Which oscillator provides the best frequency accuracy?
The oscillator with the best frequency stability and accuracy is
- Hartley oscillator.
- Colpitts oscillator.
- Tickler feedback oscillator.
- Crystal controlled oscillator.
What is Colpitts oscillator?
The Colpitts oscillator can be realized using valves, transistors, FETs or op-amp. It is much similar to the Hartley oscillator except the addition of tank circuit. In Colpitts oscillator the tank circuit consists of two capacitors in series and an inductor connected in parallel to the serial combination.
How do you calculate the effective capacitance of a Colpitts oscillator?
If C1 and C2 are the individual capacitance, then the effective capacitance of the serial combination C= (C1C2)/ (C1+C2). By using ganged variable capacitors in place of C1 and C2, the Colpitts oscillator can be made variable.
What are the advantages and disadvantages of Colpitts arrangement?
The main advantage of the Colpitts arrangement, is that the single inductor in the tuned circuit removes the effect of any mutual inductance between two coils where the alternating magnetic field built up around one inductor induces a current into the their inductor.
How to reduce the amplitude of the oscillator output?
As well as reducing the amplitude of the oscillator output by having the effect of reducing the Q factor of the tuned tank circuit, this can adversely affect both the wave shape and the frequency stability of the oscillator waveform.