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 circuit can be used as an amplifier for musical instruments or even with your cell phone. The...
This circuit, which can act as a shield, was found in a 1970s American documentation. The...
This timer produces a continuous sound at the end of the timer set in potentiometer RV1. The...