Test: Clapp Oscillator - Electronics and Communication Engineering (ECE) MCQ

 Clapp oscillator is a colpitts oscillator which has an extra capacitor series with an inductor. Hence it is an LC oscillator.

 Positive type of feedback is used in clap oscillator.

In clap capacitor, the stray capacitance has no effect in the third capacitor. So oscillator frequency is more stable and accurate. Hence when constructing variable frequency oscillator clap oscillators are preffered.

 In clap capacitor voltage divider circuit is achieved by capacitor because it is a modified version of colpitts oscillator.

 In a Clapp oscillator C₃ is much smaller than C₁ and C 2as a result, the equivalent capacitance C is approximately equal to C₃. For perfect operation C₃ should have minimum value.

Since equivalent capacitance is close to C₃ and equation is similar to colpitts oscillator.

For perfect operation of clapp oscillator value of C₃ should be C₁ parallel C₂.

The frequency of operation is given. Here effective capacitance is equal to C parallel C₂ parallel C₃.

In clap capacitor, the stray capacitance has no effect in the third capacitor. So oscillator frequency is more stable and accurate. Hence Clapp oscillator have more accurate frequency.

Frequency of clap oscillator is= 3.9 x 105 ie approximately 0.4MHz.
Therefore, frequency is equal to