We found this circuit in a Hands-On Electroncs from the 90s. The circuit uses an LED indicator. Diodes are general purpose types.
We found this circuit in 1967 General Electric documentation. SCRs can be replaced by current...
This circuit was obtained in the publication 101 Electronics Projects from 1979. The circuit can...
This circuit was suggested in an article in Radio Electronics magazine in January 1992. Other...