KOMMUTIERUNGSSCHALTUNG FUER EINEN KOLLEKTORLOSEN GLEICHSTROMMOTOR.

摘要

The commutation instants are obtd. without the use of a purpose designed sensor. The induced voltages in the motor stator windings are used to provide the reqd. information. A measured voltage (ui) is compared with a reference phase signal (sui) which depends upon the extant commutation state. The comparative signal (si) thus produced indicates whether the two quantities (ui, sui) have the same sign or not. A commutation step is ordered when the measured quantity and the reference (ui, sui) do not have the same sign. To prevent transient phenomena (which may cause spurious voltage zeros), from affecting commutation, the comparison signal (si) is suppressed for a short period after a commutation step. If no commutation step has occurred within a set, finite time, then a step is ordered. This assists when starting the motor.