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.
The output voltage is adjusted by the trimpot. The power transistor mist be mounted on a heatsink. The 3.9...
Originally, this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...
The previously mentioned versions of monostable multivibrators in this section are not...