User's Manual

Reifendruck-Kontrollsystem
Tire pressure monitoring system
Seite 3 von 4
Abbildung 3: components of the tire pressure monitoring system
The electronic wheel unit is combined with the aluminium valve to form a compact unit which is
bolted to the standardized valve bore of the rim.
Its design allows mounting in almost every known rim type. The electronic wheel unit includes an
intelligent integrated sensor which is mounted on a circuit carrier and has been developed especially
for this application. In its SMD housing, the two-chip integrated sensor contains a pressure sensor
element and an ASIC (Application Specific Integrated Circuit) with temperature sensor, measurement
acquisition unit and a signal conditioning unit. This sensor directly controls a high-frequency sending
unit. The power supply to the sensor and the sending unit is done by an environmental friendly lithium
battery which has been developed especially for the high demands on temperature resistance,
acceleration resistance and service life. In combination with the tire monitoring control unit, the typical
service life is 7 years.
2.2 Control Device
The control device consists of a high-frequency receiving module, a control device plate with
microprocessor control and the bus and diagnosis interfaces. It evaluates the received data and transmits
the information to the driver information system. It is installed in a standard series housing.
3 High Frequency transmission
The applied technique is a unidirectional high-frequency transmission of the measuring data from the
wheel to the vehicle. The high-frequency transmission is carried out in the 433-MHz- range, the socalled
ISM band or, in several countries, in the 315 MHz range. The system has been given approval
by the telecommunication authorities of the relevant countries. The data sent by the electronic wheel
system are received by the antennas mounted in the wheels and are transmitted to the control unit by
screened twisted pair cables.