Patent ID: 7212104

Claim:
A method for selectively controlling the power consumption of a piezoelectrically powered telemetry unit, the telemetry unit forming part of a tyre monitoring system and having a piezoelectric power generator including a storage device for storing charge generated by the piezoelectric power generator, the unit further including a microprocessor, a data measurement circuit, and a data transmission circuit, in which the method incorporates a power consumption protocol for regulating the consumption of power from the piezoelectric power generator, including the successive steps of: initiating power from the piezoelectric generator to the data measurement circuit for measuring data from the environment local to the unit; disabling said power to the data measurement circuit; initiating power from the piezoelectric power generator to the data transmission circuit; transmitting the measured data; and disabling said power to the transmission circuit; wherein the protocol further includes a sleep mode, the length of which is varied in dependence on the amount of charge stored in the storage device, or upon the rate at which electric charge is generated by the generator.