Abstract: An switch array for use in a motor control circuit with a power source, controller and a motor includes a plurality of bidirectional switches positioned between the power source and the motor, wherein the bidirectional switches are PWM controlled by high speed control signals from the controller to provide power from the power source to the motor as desired, wherein the switch array is positioned substantially adjacent to the motor. The power source may be a three phase AC power source. The switches are preferably bidirectional gallium nitride (GaN) switches.

Abstract: An switch array for use in a motor control circuit with a power source, controller and a motor includes a plurality of bidirectional switches positioned between the power source and the motor, wherein the bidirectional switches are PWM controlled by high speed control signals from the controller to provide power from the power source to the motor as desired, wherein the switch array is positioned substantially adjacent to the motor. The power source may be a three phase AC power source. The switches are preferably bidirectional gallium nitride (GaN) switches.

Abstract: A magnetic field measuring device useful for measuring a magnetic field associated with an electric current, including a bus section connectable into the path of the electric current, a first magnetoresistive (MR) bridge oriented to be sensitive to the magnetic field of a current in the bus section, a second MR bridge oriented to be substantially insensitive to the magnetic field of a current in the bus section, a biasing coil configured and positioned to apply a magnetic field to the first and second MR bridges, whereby the sensitivity of the first MR bridge can be controlled; and a signal processing device responsive to a voltage output of the second MR bridge to control the current through the biasing coil. The device exhibits good rejection of stray magnetic and electric fields, is convenient to use, and can be fabricated in a single chip, with or without associated signal processing and conditioning circuitry, using conventional IC processing techniques.

Abstract: A magnetic field measuring device useful for measuring a magnetic field associated with an electric current, including a bus section connectable into the path of the electric current, a first magnetoresistive (MR) bridge oriented to be sensitive to the magnetic field of a current in the bus section, a second MR bridge oriented to be substantially insensitive to the magnetic field of a current in the bus section, a biasing coil configured and positioned to apply a magnetic field to the first and second MR bridges, whereby the sensitivity of the first MR bridge can be controlled; and a signal processing device responsive to a voltage output of the second MR bridge to control the current through the biasing coil. The device exhibits good rejection of stray magnetic and electric fields, is convenient to use, and can be fabricated in a single chip, with or without associated signal processing and conditioning circuitry, using conventional IC processing techniques.

Abstract: A concentrator and sensor assembly are disclosed that use phased heaters to multiply the concentration levels that can be eluted, relative to operation with a single interactive element having a sorbent material to increase the concentration of desired gas constituents at a detector. This is accomplished here by providing two or more interactive concentrator elements that are selectively heated in a time phased sequence so that each of the interactive elements becomes heated and desorbs gas constituents into the sample fluid stream at substantially the same time that an upstream concentration pulse, produced by heating one or more upstream interactive elements, reaches the interactive element. This produces a multiplication effect that significantly increases the concentration of the gas constituents at the detector, thereby increasing the effective sensitivity of the detector.