This 4-transistor amplifier can work from 4.5 or 6 V power supplies. We found it in a Mullard transistors manual from 1960. The transistors are from the time.
Found in a 90s Popular Electronics, this circuit checks if a remote-control transmitter is...
This circuit for a decorative robot was found in the April 1988 Radio Electronics magazine. The...
This siren circuit was found in a Popular Electronics from March/April 1969. We can easily...