This general-purpose transistor audio amplifier was found in the March 1990 issue of Radio Electronics magazine. The power supply must be dual.
Found in a 90s Popular Electronics, this touch switch uses a single sensor. PLLs are common today....
We found this circuit in an old documentation from 1979. It is a logic level tester that is...
This ultrasonic insect repellent was found in American documentation from the 1980s. The...