Found in a 90's EDN, this circuit controls both the speed and the direction of rotation of a stepper motor. Relays can be replaced by MOSFETs, with circuit adaptations.
This commercial transistor radio was manufactured by RCA in the 1960s. The circuit has only 4...
This circuit has a normally low output that is triggered by a high pulse. The circuit is from...
Suggested by a 90s Popular Electronics this circuit is intended to receive volleys or whistles...