This rectangular signal generator was found in an Electronics World of 1966. The transistors are from that time and modern equivalents can be tested.
Found on 90's Popular Electronics, this circuit triggers when the microphone picks up a sound. The...
This circuit, which we found in an Argentine publication from the 1970s, uses a large high voltage...
Found in a Popular Electronics from the 90s, this circuit generates signals from 2 Hz to 30 kHz in...