Design Of A Bi-Xenon Headlight Module - Volkswagen PASSAT - YEAR 2001 Manual

The Electrics

Design of a BI-xenon headlight module

The headlight module comprises:
electronic ballast (EVG)
headlight range control motor
conventional light bulbs
gas discharge headlight module
housing with bonded clear glass lens
Until now, no single gas discharge headlight has
been capable of producing both low and high
beams. Hence, it was not possible to adjust the
light/dark boundary while driving.
A solenoid-operated mechanical shutter is used
to produce the xenon low and high beams.
This mechanism screens off a portion of the light
generated in the lamp to produce the low beam.
Lens
40
251_006
shutter Solenoid
ballast
In the high beam setting, the mechanism allows
all of the light generated in the lamp to pass
through.
Gas discharge headlight
251_067
Reflector
251_311