This circuit is from Motorola's Linear Interface ICs from 1993. The MC1723 is the equivalent of the well-known 723. The transistor supports equivalents.
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...