TUNED COLLECTOR OSCILLATOR
It is used for high frequency application .It is called tuned -tuned collector oscillation because the tuned circuit is connected to the collector .Capacitor C and primary coil L form the tuned circuits it forms the load impedance and determine frequency of oscillation
the output voltage developed across the tuned circuit is inductively coupled to base through secondary coil \( L_{1} \)
the feedback appears across base emitter junction .transistor amplifier provides 180° phase shift,and tuned circuit provides another 180° so total 360° phase shift is obtained , ie there is a positive feedback
Working
When \( V_{cc} \) is applied a transient current is developed in tuned L-c circuit -this transient current start natural oscillations in the tank circuit . these natural oscillation induce sonic voltage into \(L_{1}\) due to mutual induction which causes corresponding variation in base current these variation are amplified ß times and appear in the collector circuit .
\( \frac{1}{2π\sqrt{LC}} \) is the frequencies oscillation
MathJax example
It is used for high frequency application .It is called tuned -tuned collector oscillation because the tuned circuit is connected to the collector .Capacitor C and primary coil L form the tuned circuits it forms the load impedance and determine frequency of oscillation
the output voltage developed across the tuned circuit is inductively coupled to base through secondary coil \( L_{1} \)
the feedback appears across base emitter junction .transistor amplifier provides 180° phase shift,and tuned circuit provides another 180° so total 360° phase shift is obtained , ie there is a positive feedback
Working
When \( V_{cc} \) is applied a transient current is developed in tuned L-c circuit -this transient current start natural oscillations in the tank circuit . these natural oscillation induce sonic voltage into \(L_{1}\) due to mutual induction which causes corresponding variation in base current these variation are amplified ß times and appear in the collector circuit .
\( \frac{1}{2π\sqrt{LC}} \) is the frequencies oscillation
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