This small control for DC motors up to approximately 1 A uses an operational amplifier that admits equivalent. The transistor can be TIP29 for currents up to 1 A or BD135 for 500 mA.
This 4-function, high-pass, low-pass, band-pass and rejector filter was found in French...
Passing between a light source and the sensor will trigger on the relay by a time interval...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...