An oscillator is a circuit that converts a dc input to an ac output. This project investigates sinusoidal, output oscillators. Sinusoidal oscillators consist of an amplifier in a positive feedback loop with a frequency selective network. The amplifier can be a transistor amplifier or an operational amplifier. The frequency of the oscillator is determined by the frequency selective network. The criteria for an oscillator to produce sinusoidal oscillations are that the magnitude of the loop gain equal unity and the phase of the loop gain equal zero at the frequency selected for oscillations. An oscillator with a loop gain of exactly unity is unrealizable because of varying component values, parameters, and temperatures. To keep the oscillations from ceasing or increasing, a nonlinear circuit can be used to control the gain and force the loop gain to remain at unity. The Wien bridge oscillator of Figure 2 uses two diodes in the circuit to limit the amplitude of the oscillations. The Wien bridge oscillator without amplitude stabilization is shown in Figure 1. Wien bridge oscillators are noted for high stability and low distortion. This oscillator will oscillate at the frequency fo=1/2RC, when R2/R12