We present for the first time analytic solutions for the nonlinear dynamics of a Wien bridge
oscillator stabilised by three common methods: an incandescent lamp, signal diodes, and the field
effect transistor. The results can be used to optimise oscillator design, and agree well with
measurements. The effect of operational amplifier marginal nonlinearity on oscillator performance at
high frequencies is clarified. The oscillator circuits and their analysis can be used to demonstrate
nonlinear dynamics in the undergraduate laboratory.