Found on an 80's Radio Electronics, this circuit is designed to pass the 300 to 34,000 Hz voice range using standard operational amplifiers.
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...