RC Oscillator Circuit

An oscillator is an electronic circuit for generating an AC signal voltage with a DC supply as the only input requirement. An oscillator requires an amplifier, a frequency selective network and a positive feedback from the output to the input. The Barkhausen criterion for sustained oscillation is Aβ = 1 where A is the gain of the amplifier and β is the feedback factor (gain).The unity gain means signal is in phase. ( If the signal is 180º out of phase its gain is -1).