Air pressure warning appts. for vehicle tyres - has wheel-mounted resonator output decoded for two levels, with logic evaluation on vehicle

摘要

Anm oscillator (2) has a coil (1) attached to the side of the bodywork of a vehicle. A resonator (7) is attached to the rim of a wheel having a tyre to be monitored, and is movable up to the coil (1). It is in resonance with an e.m. wave sent out from this. It comprises a resonance coil (3), a condensor (4), a resistor (5) and a pressure switch (6). A signal processor establishes normal and abnormal tyre pressures by rectifying the output signal of the oscillator (2) and binary encodes the rectified output with a limiting two at least two levels, and logic evaluates the output signal. A warning signal (p) displays normal tyre pressure using an output signal of the processor. ADVANTAGE - Operates with twin-wheels, e.g. on buses and lorries.