This simple continuity tester, whose configuration can be found several times on this site, is powered by only 2 batteries providing the indication on an LED.
This circuit was found in a 90s Silicon Chip documentation. The current of the transformer is 1 A maximum,...
The output of this circuit using the NE5560 has the opposite polarity of the input voltage. The...
Found in an Electronic Design from the 90s, this sophisticated continuity tester uses operational...