Found in an English publication from the 1980s, this circuit can be built with equivalent transistors such as the BC549. The signal must be applied to an external amplifier.
Found in a Popular Electronics from the 90s, this circuit generates signals from 2 Hz to 30 kHz in...
This decoder filter was found in a 1975 documentation. The integrated circuits can be 741. The...
This circuit simulates dusk by slowly dimming an incandescent bulb. It was found in the August 1998...