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.
Found in documentation from the 1980s, this circuit is used for resistive loads (incandescent...
We found this circuit in a 1978 publication. It provides a different combination for alarm sensors...
This regulator provides a regulated output voltage of 48 V under a current of up to 1 A from a 60...