Wien Bridge
This Vienna bridge oscillator generates a sinusoidal signal whose frequency depends basically on C2 and C4. The circuit is from an Electronics Now from December 1993.
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
This old fashioned amplifier can source some watts to a low impedance loudspeaker. The circuit...
This 50 Hz rejector or notch filter was found in a 1975 documentation. Other frequencies can be...