Circuits, which provide sinusoidal waveforms, are but useful in themselves and form the basis of many other circuits, such as square and triangular waveform generators, and clocks. The selection of the circuits for implementation depends upon the frequency range and the stability required.
Before design begins the exact nature of the waveform must be specified as well as the accuracy and stability of its frequency. The specification given below is typical of an industrial specification.
- Describe the circuit conditions and the methods used to achieve sinusoidal oscillation.
- Explain the advantages of crystal-controlled oscillator circuits.
- Design a Wein Bridge oscillator to operate at 6 kHz +/- 5% using a 741C op amp with a +/- 11 V supply
Design an RC Ladder oscillator using an op-amp such as a LM741, 741A, 741C or a 741E. Test the oscillator using either simulation software such as the MultiSim or by building it.
Supply voltage = +/- 15 V
Oscillation frequency = 4 kHz
Accuracy of frequency = +/- 5 %
The evidence to be presented for assessment should include the following.
1. The detailed design log showing all the steps and supporting calculations. This should include any false starts and corrected mistakes.
2. The simulation documentation of any circuits designed, annotated to explain its relevance.
3. The testing log establishing its performance specification, with comments comparing and contrasting it to the original design specification.