Establishing the direct current motor drive shaft position, e.g. on starting a window winder/sliding roof motor, the motor current is monitored to give the ripple of current peaks for assessment

摘要

#CMT# #/CMT# To establish the rotary position of a direct current motor drive shaft, in the start-up phase, the ripple of current peaks is detected at the brushes from a number of rotations. The motor current is monitored for variations and a current peak is detected when the current breaches a threshold value. To check if the first current change when switching the motor on is the first current peak on transfer between brushes, the times of the second (t2) and third (t3) current peaks are measured. The statement 0= t2 2>- t3 2>is checked for its true value. With a true value 0, the statement of the number of current peaks is decremented. #CMT#USE : #/CMT# The technique is for establishing the rotary position of a direct current motor on start-up, e.g. motors for vehicle window winders and sliding roofs, etc. (Both claimed). #CMT#ADVANTAGE : #/CMT# The process establishes accurately the current peaks on starting up the motor.