Patent ID: 6445286
Filing Date: 2002-09-03
Classification: B60C

Abstract:
A method for operating a device for monitoring and wireless signalling a pressure change in vehicle tires, being preferably arranged in the tire in the form of a module including a tire valve, and comprisinga power source, a pressure sensor arranged for measuring the tire pressure at first time intervals, an analog/digital converter for digitizing a pressure signal obtained from the pressure sensor, a memory for storing the pressure signal, a transmitter for transmitting the measured tire pressure information to a receiving unit located in the vehicle, a comparator, especially one realized physically united with a microprocessor, which compares the pressure signal with a previously stored reference pressure signal and controls the transmitter in such a way that the transmitter will transmit signals at second time intervals greater than the first time intervals as long as the decrease of the pressure signal relative to the reference pressure signal (drift) does not exceed a threshold value, but will transmit signals at third time intervals smaller than the second time intervals when and as long as the drift exceeds the pressure threshold value, characterized in that the second time intervals are varied in response to one or more physical conditions that are measured in the tire and which vary during driving operation.