The sequence of logic levels applied to the inputs of and d1 determines the motor's movement. The circuit has TTL logic in the control, which must be powered by 5 V. The motor can be powered by voltages from 5 to 12 V, depending on the type, and the maximum current is 500 mA. Transistors must be equipped with heat radiators. Larger currents, up to 2 A can be controlled with TIP31 transistors. The protection diodes are of the type 1N4002 or 1N4004. The power pins of the TTL integrated units must be obtained from each datasheet.
