This simple tester was found in a Popular Electronics from the 90s. The circuit is powered by two 9 V batteries since it requires a symmetrical source.
This mono circuit for 10 LEDs was found in the January 1991 Radio Electronics magazine. It is...
This circuit was obtained from an Electronic Design of 1968. The circuit uses components of the...
We found this circuit in the Linear Applications Handbook published by National Semiconductor in...