Vehicle tyre pressure sensor for remote monitoring - uses safety valve coupled to sensor connected to induction circuit fed by modulated AC

摘要

The pressure in a tyre is detected by a safety valve which closes when a rapid fall in pressure occurs. The pressure measurement is transmitted via a tube to a sensor at the hub cover against the wheel rotational shaft. The sensor is coupled to the secondary winding which is open or closed circuited by the sensor to indicate pressure relative to a threshold value. The winding is inductively coupled to a primary winding whose current from a modulated or AC supply is measured by a galvanometer to indicate whether or not the secondary is an open or closed circuit.