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with respect to the correctness of information in this document. Copyright by AUDI AG.
34
Convenience electronics
Speed control
The torque needed to open and close the tailgate is
dependent upon several factors, such as the
momentary vehicle position, ambient temperature
and momentary tailgate position. For this reason, a
speed regulator was implemented in the control
unit; it adjusts the momentary motor speed to a
default speed characteristic. Motor speed is
controlled via a high-frequency PWM signal which
controls the motor current.
344_042
Torque bar
Magnetic coupling
Electric motor
Control unit
2nd gear
Drive lever
Manual tailgate operation
When the tailgate is moved manually from a
stopped intermediate position, the deenergised
holding torque is overcome and the "Manual" mode
is activated. This manual movement is detected by
means of Hall sensors, whereupon the control units
energise the couplings in the "freewheel" direction.
When movement stops, the couplings is
deenergised after approximately one second and
the tailgate holds its position automatically.
A second possible way to operate the tailgate
manually is to open the closed tailgate by means of
the tailgate handle button. The couplings will then
also be energised in the "freewheel" direction. This
state is maintained for approximately 0.5 seconds
after releasing the handle button. If no manual
operation is detected during this phase, the
couplings will again be energised in the "open"
direction and the tailgate will open automatically.
