This simple circuit is a continuity test that, in addition to testing resistors, can also test other components. Power is provided by batteries and the LED can be of any color.
Similar to other circuits found in this section, this circuit is from a 1996 Electronics World;...
This circuit was suggested by Motorola's Linear Databook of 1990. The integrated circuit, uncommon...
We found this circuit in a 2005 Linear Technology manual. The circuit can operate directly on 3 V to 36 V...