DC motor control method and apparatus for operating the method

摘要

The method involves controlling a dc motor (M) by means of a control circuit (ST). This circuit includes a high-side transistor switch (T1) between each motor terminal (Out1) and the positive terminal of the operating voltage. It also has a low-side transistor switch (T3) between each motor terminal and the negative supply voltage terminal. A diode (D1-D4) is connected in parallel to the switching path of each transistor switch (T1-T4). The diodes (D1-D4) are conductive in the direction from the negative supply voltage terminal to the positive supply terminal. A protective circuit (S1) is provided for each motor terminal to prevent damaging substrate currents. The high-side transistor switch (T1) or the low-side transistor switch (T3) associated with one of the motor terminals (Out1), or both transistor switches (T1,T3) is/are controlled or regulated to conduct, via the protective circuit (S1) when and for as long as the potential at this motor terminal exceeds a predetermined value.