Design analysis of a wien-bridge oscillator: from prototype to temperature performance

Abstract

A prototype Wien-bridge oscillator was designed and constructed using a single Op-Amp with a diodebridge included in the degenerative-feedback path to provide amplitude stabilization of the output oscillations. A circuit simulator, PSpice version 10.0P was also used to simulate the circuit. The simulated results were compared with those measured with an oscilloscope for validation, and it had 90% accuracy. The relationships between the operating temperature and the settling time of the oscillator, as well as the resonant frequency, were investigated and derived. The resonant frequency of the constructed oscillator is adjustable between 142.86𝐻𝑧 and 16.67𝐾𝐻𝑧. The prototype circuit in this work that measures this range of frequencies was successfully analyzed, and the investigated effects of temperature variations on the output signals are presented in section 3. The results of the temperature response to the output bias voltage, source currents, and total power dissipation of the circuit are also presented. The overall results of the presented parameters show that the operating temperature of the oscillator (within a temperature limit) has anunpredictable effect on its output, which could adversely affect the performance of the oscillator where precision is of great importance.