In order to determine this maximum torque at a given rotor
speed, the magnetic field created by the motor coils has to
be synchronized to the rotor speed with the phase between
both controlled. Then the phase range has to be scanned
through yielding a fimction torque versus phase angle with a
defined maximum. This value has to be saved for all rotation
speeds with the hction maximum torque versus speed
being the result (Figure 4).