Pressure sensor.

摘要

A pressure sensor for attachment to a tyre comprises sensing means (9) exposed to the pressure of the tyre in use and movable against resilience (11) in response to changes in the tyre pressure; and transmitting means (not shown) connected to an electrical circuit. The arrangement is such that on movement of the sensing means (9) in excess of a predetermined amount an electrical current is caused to flow in the electrical circuit, the electrical current causing the transmitting means to transmit a signal.