The LED frequency flashes depends on the value of the capacitor tested according to the table. We found this circuit in a Popular Electronics from the 80s.
This counter was found in the November 19983 issue of Radio Electronics magazine. The power supply...
This circuit was found in Electronics Handbook, Vol XIII 1993 and consists of a simple direction...
This circuit uses a General Electric coupler from the time of the publication in the 1980s....