Suggested by General Electric in a 1970 document, this circuit uses a LASCR, or SCR fired by light. This component is uncommon today.
This circuit can be used to test continuity or even semiconductors. We found the configuration in a 1987...
We found this circuit in a 1978 publication. It can be implemented with modern transistors like...
This circuit is from Motorola's Linear Databook from 1990. The integrated circuit and transistors are...