tyre pressure sensors

[Gisacloo]

How do the sensors in tyres send a signal to the cars computer, when the pressures go down?

[pug100]

Try this, it's an American site so it refers to ' tires' throughout the article.

http://en.wikipedia.org/wiki/Tire_pressure_mon itoring_system

Companies like Schrader Electronics designed first generation TPMSs using battery powered radio transmitters, with sensors mounted on a standard tire valve, and a chassis mounted radio frequency receiver.

Typical RF TPM systems employ four or five battery powered transmitter-sensors,[6] one RF receiver (either stand-alone or integrated in other vehicle electronics), and some other satellite hardware which can perform the function of identifying the tire position involved in the inflation anomaly. Each tire pressure sensor can periodically trigger a transmission of pressure status, or be polled continuously on demand.

Automakers require a battery lifespan of between seven and ten years, so TPMS system designers use power saving techniques to extend the battery life. The heart of the sensor is a silicon application-specific integrated circuit (ASIC) chip, which can manage critical power saving algorithms and other functions of the sensor. However, there remains the fundamental problem that all batteries eventually become exhausted, and this represents safety and replacement cost issues for the consumer.

[Toureman]

I think I can give you a simple answer as my Renault has them.

Each tyre valve has a tyre sensor / radio transmitter attached to it inside the wheel rim it is very small. This transmitter then sends a signal to a black box under the car which is wired to the display on the dash, and through a computer, it continually monitors the tyre pressures and will tell you the pressure in each tyre. If a pressure gets below a certain pressure a red light and buzzer lets you know you have a puncture. Each sensor has a different code for each wheel.

If you have a puncture and fit the spare the display only shows the car has three wheels unless the punctured tyre is in the boot, if it is in the boot it will show you have one flat tyre !

[ssensor]

we don't have the tyre pressure sensor,but if you need other pressure sensors like piezoresistive pressure transducers,automotive pressure sensor,oil pressure sensor,AC pressure sensor,check the company www.sendo-sensor.com