This bidirectional motor control was found in an 80's Electronic Engineering. The circuit uses a component of the time and is suitable for motors up to 1 A.
This is the basic configuration of an operational amplifier sample & hold circuit. The FET and...
The integrated circuit 4136 consists of operational amplifiers of type 741 in the same enclosure and...
We find this circuit in a 1987 publication. It makes use of comparators constructed around the 741...