Re: quickclear windscreen


"Pete M" <pete.murray@xxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:fuiq7g$3vh$1@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Al wrote:
I believe the rain sensors are just IR transmitters/receivers inside
the car behind/on the rear view mirror, so changing the windscreen
shouldn't make a difference.
Err no, those are for the auto-dip rear view mirror.

Err no, they are behind the mirror. Autodip sensors are at the front of
the mirror. Schoolboy error, stand in the corner.

ITYF that auto dip mirrors have a sensor on the back and another one on
the front built into the mirror casing.

Thank you pete.



The rain sensor is stuck to the glass and uses a HF emitter and
receiver- the resonance of the glass changes when its wet.

What a load of bollocks.

Optical sensors utilise light and the principle of total internal
refraction within glass. In its basic form an optical sensor consists of a
light source, a light detector and an optical assembly. The optical
assembly is two lenses and or light guides. A beam of light is directed
through the optical assembly into the windscreen glass, the light is
?trapped? within the glass due to total internal refraction. This is the
principle used in fibre optic cable. The light bounces from the outside
surface of the glass back to the inside surface of the glass until it is
picked up by the second optical assembly. If rain falls on the glass
within the sensing area, light ?breaks free? as it is directed into the
water droplet, this causes a corresponding reduction in the received
light. Usually a microprocessor is used to distinguish between different
amounts of rain and runs algorithms to provide best wiping results. This
is why it'd be *** all use mounting the sensor for automatic wipers on
the interior mirror, and is why the sensor is stuck to the glass.


I was only aware of the Ford system I mentioned above.

Tim..


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