Wideband Wien Oscillator with Single-Gang Pot
This Wien bridge oscillator (after Max Wien, 1866–1938) produces a low-distortion sine wave of constant amplitude, from about 15 Hz to 150 kHz. It requires just four opamps and will work off a single 9-volt battery. Also, unlike most Wien bridge oscillators, it does not require a dual-gang potentiometer for tuning.