We found this circuit in a Radio Electronics magazine from November 1976. The clock frequency is divided by 10 and the maximum value depends on the integrated circuits used.
Found in documentation from the 1970s, this circuit uses an oscillator and a display to warn of...
This circuit indicates whether a cable or wire is energized by simply approaching its antenna. The...
Using bipolar, FETs and unijunction this long-lasting timer can reach 10 hours with good quality...