How to use op amps with a single rail power supply?
Method #1: Voltage divider using two resistors. Method #2: Voltage divider using two Zener diodes.

Wien-bridge Oscillator using Op-Amp The Wien-bridge oscillator, as shown on the basic outline of the diagram below, consists of an Operational Amplifier (OA) in a non-inverting configuration with gain 1+R2/R1 and a RC feedback network with the following transfer function: Where: Combining the first and the second equation we get: The loop gain (BA) is: The Barkhausen criterion […]

Nonlinear Amplitude Control of a Sinusoidal Oscillator In any practical oscillator, the loop gain (ßA) must be slightly greater than unity to prevent that the tolerance parameters of components, aging, temperature effects, etc., make that ßA < 1 and the circuit not meet one of the oscillation conditions specified in the equation: In which case the […]