Found in the July 1980 Radio Electronics magazine, this circuit uses an integrated circuit from the time and a power Darlington. The Darlington must be equipped with a heat sink.
We found this circuit in an old American publication. The transistors can be BC558 and diode 1N34....
This simple circuit operates with only 1.5 volts of a battery and detects low resistance making a...
The cascade connection of two flip-flops allows division by 4, as shown in the figure. Note that...