Insufficient tyre pressure alarm device - has pressure sensor at each wheel transmitting to receiver in driver's cabin

摘要

The alarm indicator signals that the tyre pressure on a motor car or lorry is too low. This prevents accidents and is achieved by a pressure detector at each wheel which transmits a signal to a receiving unit in the driver's cabin. A wheel unit (100) at each wheel comprises a pressure sensor or air mass sensor which provide their signals via an electromagnetic power generator to a transmitter assembly (200). Each transmitter emits a pulse modulated signal via an antenna (152). These signals are received at a common receiving antenna (302) where the signal is amplified and detected (300 A-C) for decoding to identify the wheel. If a signal is missing for a time period, an alarm (300D, E) is operated for display in the drivers cabin. The electromagnetic generator comprises a U-shaped coil operating in conjunction with a permanent magnet.