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.
On this website we show how to calculate the components of this circuit for other frequencies. The basic...
We found this circuit in an English publication from 1980. The transistor can be either the BC548...
Found in Popular Electronics from the 90s, this circuit mutes a scanner's speaker in the absence of a...