From an audio signal, this circuit gets two signals of the same amplitude and opposite phases. This setting is widely used in bridge amplifiers (BTL). Transistors may be commonly used as BC series.
We found this test circuit in Radio Electronics magazine from July 1962. The circuit uses...
We found this circuit in an American publication from the 1980s. Equivalent modern operational amplifiers...
The transistors in this circuit can be the BC548. Capacitors determine the frequency and can be...