This circuit is from 2005 documentation. The integrated amplifier circuit must be mounted on a good heat sink and the speaker must be able to withstand the full power of the circuit.
We found this circuit in Radio Electronics magazine from April 1960. It works for both NPN and PNP...
This is an audio amplifier typical of an old tape recorder. The circuit is from a Radio...
This circuit uses a selector switch to select resistors for timings given in seconds. Capacitor C1 can be...