Found in Popular Electronics from the 90s, this circuit uses still common components. Its power is 20 W, requiring care when winding the transformers.
This amplifier with very high input impedance was suggested by Texas Instruments in a manual of...
Using only a ULN5804 integrated circuit, stepper motors up to 500 mA can be controlled from TTL...
Constant current sources are used in applications such as battery chargers, electrolytic tanks, etc....