Transense: Automotive Sensor IPR for Honeywell, Michelin & The World.

DT - An excellent link highlighting all the problems associated with the sharp end of battery TPMS, which my posts 15,455/62 to Cantata related to. All 8-pages are a must read as you say.

Luckykids is spot on in his post above, there's such an abundance of prevailing ignorance about TPMS. The author of the article, although at the centre of the chaos as an independent tyre dealer and therefore keen to know the facts, hasn't it appears done a simple Google search on batteryless sensors or the Tread Act. If he had, he would be aware of the coming change spearheaded by TRT and would know that Indirect tyre monitoring as touched on in page 7 is banned on new cars after Spt 07 and this will become a diminishing problem.

The below quote is a common example of the box of tricks contained in a non-TRT batteryless sensor, otherwise known as transponder or button. One of these is required for 'each' wheel, whereas a TRT-based system needs only one equivalent fitted in the Texas Instrument DSP, with TRT's wheel sensors themselves cheap & simple in comparison. The cost & complication between TRT and other batteryless systems is a primary competitive advantage, while battery sensors are a dark age story that should go out of print over the next couple years. Then there are TRT torque & non-automotive sensors to come.

"The Transponder ASIC consists of a micro-machined pressure sensor, a temperature sensor, the sensor readout, EEPROMs, the HF front-end and a micro-controller. The HF front-end rectifies the induced AC voltage supplied by the resonator to generate DC voltage supply. It contains an excess voltage protection assisting the external clamp diodes for small reading ranges. The clock is extracted from the induced AC voltage. The HF contains a load modulator and also a clock fail indication as well as a power fail indication for micro-controller and sensor readout."