Eddy current turbocharger blade speed detection

Journal Article · Wed Sep 01 00:00:00 EDT 1982 · IEEE Trans. Magn.; (United States)

DOI:https://doi.org/10.1109/TMAG.1982.1061962· OSTI ID:5972039

Rickman, J Jr

A commercially available magnetic reluctance sensor is used to determine the angular velocity of turbocharger impeller blades from outside the aluminum housing. Eddy currents are induced in the aluminum blades by blade motion through the magnetic field projected by an externally mounted samarium-cobalt permanent magnet. Experiments show that secondary eddy currents and associated ac magnetic fields generated in the aluminum housing provide the prime excitation for a sensor coil located outside the housing. The coil output voltage spectrum shows a strongly peaked structure with peak locations at multiples of the blade passage frequency in the range 1-10 kHz. The sensor output signal decreases with increasing frequency above 2 kHz because of increasingly effective attenuation by the housing. Test results show that a circuit designed to track the blade signal gives an analog voltage output proportional to the frequency of blade passage over the operating range of the Cummins VT-903 and Detroit 8V-71T turbocharged diesel engines. Suggestions are made for the design of a sensor appropriate for both magnetic reluctance and eddy current sensing applications.

• OSTI ID: 5972039
• Journal Information: IEEE Trans. Magn.; (United States), Vol. MAG-18:5
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
TURBINE BLADES
EDDY CURRENTS
ANGULAR VELOCITY
DIESEL ENGINES
ELECTRIC POTENTIAL
ELECTRONIC CIRCUITS
MAGNETIC FIELDS
PERMANENT MAGNETS
SUPERCHARGERS
TURBOGENERATORS
COMPRESSORS
CURRENTS
ELECTRIC CURRENTS
ELECTRIC GENERATORS
ENGINES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MAGNETS
VELOCITY
330300* - Advanced Propulsion Systems- Electric-Powered Systems