Abstract: A measuring circuit (MS) for measuring the value of an impedance in an impedance network includes an oscillator device (OSZ1), a second oscillator device (OSZ2), a phase-controlled rectifier (PG), a reference/actual value comparison point (AG) and an integrator.The first oscillator device feeds a first alternating voltage of constant amplitude and constant frequency to a first output connection (A1). The second oscillator device feeds a second alternating voltage of the same frequency, but with adjustable amplitude and with phase shifted by 180.degree., to a second output connection (A2). The amplitude of the second alternating voltage depends on the phase of the signal which is transmitted to the phase-controlled rectifier via an input connection (E). If the input signal is in phase with the second output signal, the amplitude of the second output signal is reduced. However, if the input signal oscillates in opposite phase to the second output signal, the amplitude of the second output signal is increased.

Abstract: An air gap detector for use in antilocking brake systems includes an active integrator that integrates an output signal from a wheel speed sensor, that depends in part on the relative spacing between the wheel axle and its associated bearing, to thereby produce a signal that is inversely proportional to the air gap between the axle and bearing. The integrated signal is processed by peak detecting means to produce a peak signal that is proportional to the size of the air gap. The peak signal is then amplified and adjusted to produce a D.C. signal that is proportional to the size of the air gap.

Abstract: A new and improved spark plug testing apparatus is in the form of an electrically conductive, metallic spring clip and includes a pair of first electrically conductive contact portions for contacting an electrically conductive externally threaded portion of a spark plug. A first resilient portion is connected to the pair of first electrically conductive contact portions for clamping the first electrically conductive contact portions onto the electrically conductive externally threaded portion of the spark plug. A pair of second resilient portions is connected to the respective first electrically conductive contact portions, and a pair of second electrically conductive contact portions is connected to the respective second resilient portions, such that the first resilient portion urges the second electrically conductive contact portions onto an electrically conductive internally threaded portion of a spark plug receiving aperture on an internal combustion engine.

Abstract: A SQUID fluxmeter, which object is to accurately measure magnetic flux even if the input magnetic flux is largely changed in a short time, includes an 1-input superconducting OR gate for outputting pulses to the number of i in response to one input pulse from a SQUID, an AC bias current source for outputting a current I.sub.C of variable frequency 4if to a bias input node of the OR gate, an up/down counter for counting pulses from the SQUID and a control circuit for outputting a control signal CSi to the AC bias current source corresponding to the time differential value of the count value C1 of the counter and present value i. The response speed of the magnetic flux feedback through the feedback coil to the SQUID in response to the magnetic flux input to the SQUID is thereby made i times higher than that in the prior art.

Abstract: A magnetic inspection device for detecting structural faults in elongated magnetically permeable objects has two opposite magnetic poles, at least one pole being an end pole, that induce a first magnetic flux axially in a first section of an object between the poles, and an oppositely directed magnetic flux in another section adjacent the end pole. As the device and object move relative to one another, eddy currents induced in the object by the changing longitudinal fluxes at the end pole are detected to locate structural faults in the object.

Abstract: A peak amplitude detector for use in a synchronized position demodulator associated with a linear variable differential transformer. The peak amplitude detector adjusts for phase shift in the transformer and maintains the full bandwidth of the transformer. The detector obtains the maximum positive or negative amplitude of the sinusoidal signal at one of the secondary windings of the transformer by first counting either a positive or negative half cycle of the signal and then while down counting one half of the counted half cycle sampling the amplitude of the sinusoidal signal. The sampling ends when the count reaches zero.

Abstract: A motion transducer for measuring the displacement of, for example, shafts in gas control modules. The shaft 14 carries two magnets 10, 12 each of hollow cylindrical form, the magnet 10 presenting a south pole everywhere over its external cylindrical face and the magnet 12 presenting a north pole everywhere over its external cylindrical face. The shaft 14 moves vertically past an array of Hall-effect sensors 18-24 to produce sinusoidal voltage outputs at the sensors. The outputs are combined in a summing amplifier (FIG. 3). The combined output is not affected by rotation of the shaft and magnets nor by tilting or sideways displacement of the axis 16 of the shaft. That is because no matter what the rotational position is the sensors are always subjected to the same magnetic field and, if the shaft tilts or is displaced sideways an increased field at some sensors is compensated by a decreased field at others.(FIG. 1 is suggested as the accompanying drawing).

Abstract: A method for real time processing of information received from a plurality of permanent magnets embedded in the pavement of an Intelligent Vehicle Highway System. A sequence of magnet orientations provides coded information to sensors mounted on automotive vehicles. The method uses a combination of extended Kalman filtering and Schweppe likelihood estimation to determine the relative location and orientation of the magnets. A separate location estimator (extended Kalman filter) is provided for each of the possible magnet orientations. A decision process identifies the most likely orientation of the magnet, and the Kalman filter selected by the process contains the best estimate of the location of the magnet. Schweppe likelihood estimation is extended to use the detector as a decoder of the information provided by the orientation sequence of the magnets.

Abstract: A process and apparatus are provided whereby sulfur and nitrogen oxides as well as carbon monoxides and unburned hydrocarbons are removed from internal combustion engine exhaust gases. The gases are passed through a chamber containing a sulfide and an oxide of iron, copper or zinc. The system is partially self-regenerating and can be used in conjunction with present catalytic converter units or in lieu thereof. In certain embodiments the present invention can also replace muffler units in exhaust systems.