Power window position recognition, function - GF72.29-P-4000S

MODEL 215, 220 

Direction of rotation recognition 

Fig 1: Direction Of Rotation Recognition

Function 

Two hall sensors each (b1, b2) are located on the shafts of the power window motors (M10/3, M10/4, M10/5, M10/6)  . These hall sensors react to motion of the magnet outputting one rectangular pulse per rotation of the motor shaft. The corresponding control modules (model 220: N69/1, N69/2, N69/3, N69/4; model 215: N69/1, N69/2 and N22/6) sense these pulses and evaluate them for rotation direction and position recognition.

Rotation direction recognition 

The control module in question recognizes the direction of rotation of the power window motor from the time offset between the pulses from hall sensor b1 and the pulses from hall sensor b2.

Position recognition 

The control module counts the pulses from the 2nd hall sensor considering the direction of rotation of the motor. The value in the position counter increases as the window closes. When the window opens the value in the position counter decreases. The upper mechanical stop is defined as the zero position, i.e. when the window is completely rolled up the counter should be set to zero. The zero position is set by synchronization  . When the zero position in the opening direction is exceeded the counter value is negative and thereby invalid. In this case resynchronization is accomplished.