This circuit was found in the October 1987 Radio Electronics magazine. The circuit is a PWM control with a 555. It appears that the 555 is missing a connection that would be pin 4.
This symmetrical 1.2 to 35 V source was found in a 1994 documentation. The integrated circuits are...
Found in a 90s Elektor, this mixer makes use of integrated circuits of the time. The supply must be...
This amplifier is specifically designed for portable radio and recorders with a 4 ohms load....