The circuit shown is from Motorola's 1990 Linear Databook. Shaded components are optional. The characteristics of the coils are given next to the diagram.
We found this circuit in an old American documentation. SCRs can be modern equivalent types. The...
We found this circuit in a 1990 documentation. The operational amplifiers are type 741 and the LED is...
This fast-acting circuit uses a 555. We found it in the November 1992 Radio Electronics magazine. The...