This is the traditional H bridge configuration for motors. The circuit is for currents up to 500 mA, but with higher power transistors such as the TIP31 motors up to 2 A can be controlled.
Using the 741 operational amplifier this circuit was found in the August 1993 Electronics Now...
The integrated circuit used in this application is a double 741 from SGS. The supply must be...
For this function, a little more sophisticated, we need switches (keys) or double sensors. This is...