Measurement of conducted transients on automotive sensors

Honeywell has developed a new concept for high frequency conducted transient measurements at automotive sensor connectors directly on the vehicle using a special interface covering the DC to 18 GHz frequency range. Conducted transients were captured using both a digitizing oscilloscope TDS-794D and HP spectrum analyzer to analyze single event-conducted transients and harmonic content. The objective of the test was to correlate in vehicle radiated and conducted electromagnetic spectrum signatures of an automotive sensor, developed by Honeywell Sensing and Control, with component level EMC qualification tests. Vehicle tests were performed at the Southwest Research Institute Facilities in San Antonio, Texas. Testing was performed in a shielded, semi-anechoic chamber and on a dynamometer during the driving cycle and during system operation modes such as idle, running, braking, and at speed. A preliminary investigation was also conducted to determine the immunity of the sensor to radiated electromagnetic fields from narrowband sources inside the engine compartment and outside the vehicle. The overall objectives of this project were to develop an accurate specification for new Cam/Crank sensor designs and to validate component level RFI/transient test procedures that can be used as a means of developing or specifying the electromagnetic interference intensity produced by a new vehicle on a standardized basis