This circuit was found in an old publication from 1989 but can still be assembled today with BD135 transistors for motors up to 500 mA and up to 3 A using the TIP31 paraQ2. The diodes can also be 1N4002 or 1N4004. 6 to 12 V motors can be controlled easily. The transistor Q2 must be equipped with a heat radiator. RV1 can be 4k7.
