BorgWarner Unveils New Turbocharger Speed Sensor

KIRCHHEIMBOLANDEN, GERMANY (Aug. 6, 2007) - Turbocharger speed sensors play a vital role in providing "overspeed" protection in turbocharger systems. Continuing the development of its eddy current speed sensor, BorgWarner Turbo & Emissions Systems has unveiled its latest innovation, which will be available in the first quarter of 2008. 

Key features provided by the new speed sensor include:

* Compact design: Many parts of the discrete electronics, such as circuitry components, have now been installed in an application-specific integrated circuit (ASIC) and therefore require less space. In contrast to previous models, the eddy current speed sensor is no longer mounted on the bearing housing but is now directly attached to the compressor housing, where it is exposed to lower temperatures. Nevertheless, it was still necessary to use an ASIC with advanced high-temperature silicon-on-insulator (SOI) technology together with hybrid electronics to ensure that the electronics can withstand temperatures of up to 180 degrees C. 

* Flexibility: For the first time, these sensors can be installed not only in commercial vehicle engines but also in passenger cars, either with single-stage or two-stage turbocharger systems.

* Less wear and maintenance: The new sensor has been designed to extend service life to 1 million miles. The new eddy current speed sensor is a "non-pigtail" solution with integrated electronics. The previously used passive speed sensor was based on the inductive principle without a supply voltage. By contrast, the new sensor is a five-volt active speed sensor that transmits a rotational speed signal to the engine management unit. By using the eddy current effect, the sensor operates without contact, and is therefore mechanically wear-free and requires no maintenance. 

* Measures the speed range up to 350,000 rpm: In spite of the extremely high temperatures involved, the speed sensor is able to recognize the blade position of the compressor wheel. The new generation of turbocharger speed sensors can measure rotation from very low speeds of about 1,000 rpm up to extremely high speeds of 350,000 rpm. The integrated electronics evaluates the sensor signals and determines the exact speed of the compressor wheel. 

* Improved electromagnetic compatibility (EC): The unit's EC has been improved to ensure that the sensor does not cause any electromagnetic interference that might impair the operation of other systems.

(Source: BorgWarner Turbo & Emissions Systems)