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.
With this circuit it is possible to excite direct current relays from an alternating signal,...
This circuit is from an old documentation. The integrated circuit can be replaced by a modern...
The FET can be a BF245, and the other transistors can be the BC548 and BC558 in this simple AM...