This circuit is from a publication from the 70s. The operational amplifier is from the period. Modern equivalents according to the motor current must be used.
This circuit was found in a 90s EDN. Its purpose is to increase the efficiency of operational...
This LED indicator circuit uses an LM339 comparator. The circuit was found in the January 1995...
This circuit was found in an 80's General Electric documentation. The circuit uses uncommon...