Found in the February 1997 Electronics Now magazine, this circuit controls motors according to the transistor used. For the transistor indicated, the maximum current is 200 mA.
In the figure we have the way to use a stepper motor as an encoder. Operational amplifiers can be of...
Placed inside the refrigerator, this circuit triggers an oscillator when the part is opened...
We found this circuit in an old documentation from the 70s, but it can be assembled with more...