A magnetic transducer fits over a rotatable shaft and has a primary winding that is a-c energized by an a-c excitation signal to produce a magnetic field, adjacent to the shaft, which changes as the shaft is torsionally stressed when torque is applied thereto. This stressing causes compression and tension in the shaft which alter the shaft permeability and thus vary the magnetic flux pattern in the shaft. The magnetic field is also a function of the shaft speed due to the shaft's armature reaction, eddy currents being generated in the shaft which develop a magnetic field that opposes and distorts the field produced by the primary winding. A pair of secondary windings in the transducer produce differently modulated excitation signals which are then processed to provide a pair of suppressed carrier signals amplitude modulated at different phases by the torque and speed parameters of the shaft. Synchronous detectors are employed to demodulate the suppressed carrier signals to provide separate torque and speed information signals.

Force measuring equipment has a magnetoelastic transducer with an excitation winding supplied with alternating current, which generates a primary flux in a magnetic core of the transducer, and a measuring winding in which a signal voltage is induced, the signal voltage giving a measure of the force applied to the transducer core. The signal voltage is supplied to signal processing members which are arranged to form an output signal by phase-sensitive rectification of the signal voltage. Control members sense when the primary flux passes a positive and a negative reference level, and switch polarity reversing members at the times during each period of the AC supply when the primary flux with a certain sign of its time rate of change passes the positive reference level and with the opposite sign of its time rate of change passes the negative reference level.

A magnetic transducer fits over a rotatable shaft and has a multi-pole magnetic core, one primary winding being wound on half of the poles while a second primary winding is wound on the other half. Direct current pulses are alternately supplied to the two primary windings to provide a-c excitation for producing an alternating magnetic flux or field, adjacent to and within the shaft, which changes as the shaft is torsionally stressed when torque is applied thereto. This stressing causes compression and tension in the shaft which alter the shaft permeability and thus vary the magnetic flux pattern in the shaft. The resulting magnetic field is also a function of the shaft speed due to the shaft's armature reaction, eddy currents being generated in the shaft which develop a counter magnetic field that opposes and distorts the field produced by the two primary windings. A secondary circuit in the transducer, comprising a pair of secondary windings each wound on a separate magnetic core, responds to the resulting magnetic field and provides information signals relative to the torque and speed characteristics of the rotating shaft.

A method and apparatus for determining the weight of a vehicle or the power output of its engine which comprise measuring either or both of acceleration and velocity of the vehicle, measuring the force causing the acceleration or velocity by measuring deformation or displacement of a drive train member, and then evaluating the weight of the vehicle from the measurements of acceleration and force and the engine power output from the measurements of velocity and force.

A magnetic transducer fits over and encompasses a rotatable shaft and has a primary or excitation magnetic assembly having a winding arrangement that is energized to provide a-c excitation for producing an alternating magnetic flux or field, adjacent to and within the shaft, which is modified as the shaft is torsionally stressed when torque is applied thereto. This stressing causes compression and tension in the shaft which alter the shaft permeability and thus vary the magnetic flux pattern in the shaft. The resulting or modified magnetic field is also a function of the shaft speed due to the shaft's armature reaction, eddy currents being generated in the shaft which develop a counter magnetic field that opposes and distorts the field produced by the primary winding arrangement. A pair of secondary or pick-up magnetic assemblies, having secondary windings, respond to the modified magnetic field and provide information signals relative to the torque and speed characteristics of the rotating shaft. The size, weignt, cost and complexity of the transducer are substantially reduced by constructing the three magnetic assemblies so that the primary and secondary windings are effectively wrapped around the shaft with the winding turns and the shaft sharing the same axis, the magnetic field thereby being parallel to the shaft. Relatively short poles extend radially inwardly from the magnetic assemblies toward the shaft to control the magnetic flux paths and maximize the amount of flux passing through the shaft.