Title of the experiment: Hartley oscillator (High frequency Sine wave generator).
Aim: To simulate Hartley oscillator (High frequency Sine wave generator).
1. MULTISIM Software Loaded PC 1 No.
2. Printer 1 No.
2. Design Circuit
3. Simulation Procedure
4. Output Waveform
The Hartley Oscillator design uses two inductive coils in series with a parallel capacitor to form its resonance tank circuit producing sinusoidal oscillations.
• Open MULTISIM Software.
• Click=> New => Design1
• Click save as in Desk Top rename the Design1 to your circuit name.
• Go to Component tool bar and select the components.
• Draw the circuit diagram of Hartley oscillator.
• Connect the CRO above mentioned circuit.
• Click simulate button or press F5 key => RUN
• Note down the Time period and calculate the frequencies.
• Record the output waveforms.
Thus the circuit is designed to simulate the Hartley oscillator and the output graph is printed.
Questions with answers:
1. Which configuration of the transistor amplifier is used for Hartley oscillator?
Explanation: Common emitter transistor configuration is used in Hartley oscillator to ensure good oscillation.
2. Phase shift provided by the overall tank circuit in Hartley oscillator is __________
Explanation: Phase shift provided by the tank circuit is 180 degrees to obey Barkhausen’s criteria for sustained oscillation.
3. The gain device in the Hartley oscillator act as a __________
Explanation: The gain device in Hartley oscillator act as a band pass filter.
4. The phase difference produced by the active element of Hartley oscillator is __________
Explanation: The coil has a tap such that the proper phase is available to the base of the transistor. Value of L and C are adjusted to give a phase shift of 180°. The transistor itself creates a 180° phase shift and hence total shift is 360°/0.
5. Hartley oscillator make use of ________ amplifiers.
Explanation: Hartley oscillator make use of class C amplifiers because it can amplify signals less than 180 degrees and provide output of full cycle.
All experiments should be designed and verified through simulation tools like Multisim.
1. Zener diode (Forward and Reverse bias characteristics)
2. Rectifier circuits ( Half wave, Full wave, Bridge rectifier with filters)
3. Power supply with Zener diode as Regulator
4. Common Base transistor output characteristics
5. Common emitter amplifier (Implementation of Current Series negative feedback)
6. Emitter follower (Implementation of Voltage Series negative feedback)
7. RC Coupled amplifier (Implementation of the concept of multistage amplifier)
8. Clippers and Clampers
9. RC Phase shift oscillator (Medium frequency Sine wave generators)
10. Hartley oscillator (High frequency Sine wave generator)
11. Astable Multivibrator (Square or Rectangular wave generator)
12. Gate triggering of SCR with various gate currents.