Abstract: A method for accurately measuring the conductivity of substances. This method incorporates two points of measurement that are isolated from each other. Each of these points is in contact with the substance to be measured. A continuous, constant electrical current is passed through the substance at the measurement points by means of an electrical force that is not constant but varies depending upon the amount of electrical force required to maintain the constant electrical current through the substance. This constant current is passed through the substance in two directions. This change in direction is achieved by reversing the polarity of the electrical force across the two measurement points. The time periods for each of the two directions of constant current flow are equal. The amount of electrical force or voltage that is required to maintain this constant amount of current is directly related to the resistance of the substance.

Abstract: A method for accurately measuring the electrical conductivity of substances. This method incorporates two points of measurement that are isolated from each other. Each of these points is in contact with the substance to be measured. A continuous, constant electrical current is passed through the substance at the measurement points by means of an electrical force that is not constant but varies depending upon the amount of electrical force required to maintain the constant electrical current through the substance. This constant current is passed through the substance in two directions. This change in direction is achieved by reversing the polarity of the electrical force across the two measurement points. The time periods for each of the two directions of constant current flow are equal. The amount of electrical force or voltage that is required to maintain this constant amount of current is directly related to the resistance of the substance.

Abstract: Under the present invention storage grid manager is provided that receives requests for storing files from users, based on certain performance parameters, the storage grid manager identifies selected storage cells of the enterprise storage system for storing the files. Thereafter, the storage grid manager routes the requests to the storage grid controllers associated with the selected storage cells. The storage grid controllers control access to the storage cells to ensure that only authorized access is granted. Once the files are stored, the storage grid manager will update a mapping to identify the precise storage cells in which each file is stored. Therefore, when a user issues a request to retrieve a file, the storage grid manager consults the mapping, identifies the corresponding storage cell and retrieves the file.

Abstract: A system for testing the electrical conductivity of printed traces, on multiple surfaces, of a printed wiring board using non-contacting probes. The non-contact probes generate a plasma in a plasma generating chamber that is used to apply a voltage to the printed wiring board. A measurement circuit determines the magnitude of the voltage on the printed wiring board.

Abstract: There is provided a position control drive system having first and second drive units linked together and travelling on parallel running rails. A passive unit riding on a third parallel running rail is pivotally linked to one of the drive units. The pivoting link allows movement of the drive units longitudinally along the rails, but prevents movement in other directions. The pivot compensates for positional differences between the electronic positional control of the drive units and the mechanical linkage preventing the inefficiency in the electronic system, stresses in the mechanical system and, in severe cases, binding of the drive units to the rails.

Abstract: There is provided a position control drive system having first and second drive units linked together and travelling on parallel running rails. A passive unit riding on a third parallel running rail is pivotally linked to one of the drive units. The pivoting link allows movement of the drive units longitudinally along the rails, but prevents movement in other directions. The pivot compensates for positional differences between the electronic positional control of the drive units and the mechanical linkage preventing the inefficiency in the electronic system, stresses in the mechanical system and, in severe cases, binding of the drive units to the rails.

Abstract: An improved induction motor control system. Single-phase and three-phase AC induction motors are controlled in accordance with the equation y=m=x+b, where y is the phase angle, m is the slop, x is the firing delay and b is the offset. Subsequently, the firing delay is increased by predetermined amounts, the behavior of the phase angle is evaluated for several cycles, and the motor is controlled based on the results of the evaluation, thereby minimizing energy consumption.