This circuit was found in Motorola documentation from the 1980s. The components are of the time, not currently common as operational and opto receiver.
We found this circuit in the May 1996 Electronics Now magazine. The relay must have a voltage...
The shield circuit shown is from the 1994 Linear Applications Handbook by National Semiconductor of 1994....
Up to 0.5 A DC motors can be controlled by this circuit. Direction change is achieved by a logic...