In this note, we are discussing about the Tuned Collector Oscillator, and about the circuit diagram of Tuned Collector Oscillator and Working of Tuned Collector Oscillator. Welcome to Poly Notes Hub, a leading destination of Diploma Engineering Notes.
Author Name: Arun Paul.
What is Tuned Collector Oscillator Circuit ?
Fig shows the circuit of the tuned Collector Oscillator. It contains tuned circuit L1 – C1 in the collector hence the name. The frequency of Oscillations depends upon the values of L1 and C1 and is given by:
f = 1/(2π√L₁C₁)
The feedback coil L2 in the base circuit is magnetically coupled to the tank circuit coil L1. In practice, L1 and L2 form the primary and secondary of the transformer respectively. The biasing is provided by a potential divider arrangement. The capacitor C connected in the base circuit provides a low resistance path to the oscillations.
Circuit Diagram of Tuned Collector Oscillator
Working Principle of Tuned Collector Oscillator
When switch S is closed, the collector current starts increasing and charges the capacitor C1. When this capacitor is fully charged, it discharges through coil L1, setting up an oscillation frequency determined by exp(1). These oscillations induce some voltage in coil L2 by mutual induction. The frequency of voltage in coil L2 is the same as that of the tank circuit but its magnitude depends upon the number of turns of L2 and the coupling between L1 and L2.
The voltage across L2 is applied between the base and emitter and appears in the amplifier form in the collector circuit, thus overcoming the losses occurring in the tank circuit. The number of turns of L2 and coupling between L1 and L2 is so adjusted that oscillations across L2 and amplifier to a level just sufficient to supply losses to the tank circuit.
It may be noted that the phase of feedback is current i.e. energy supplied to the tank circuit is in phase with the generated oscillations. A phase shift of 180° is created between to voltages of L1 and L2 due to transformer action. A further phase shift of 180° takes place between the base-emitter and collector circuits due to transistor properties. As a result, the energy feedback to the tank circuit is in phase with the generated oscillations.
Application of Tuned Collector Oscillator
- Use to generate Sin Wave.
- Use in different type of frequency generator.
Conclusion | Diploma Engineering Notes | Poly Notes Hub
Here we discuss an oscillator circuit called a Tuned Collector Oscillator and about Circuit and Working Principle. Our Poly Notes Hub provides syllabus-wise notes for polytechnic or diploma engineering students of streams like Electrical Engineering, Electronics Engineering, Electrical and Electronics Engineering, Electronics & Instrumentation Engineering, and Computer Science & Technology. Our website is updating day by day so keep in touch with us for new and syllabus-wise notes and topic which helps you all to do any task regarding diploma engineering.