Abstract: The invention relates to an inductive position detector (1) comprising a first member (9) having a longitudinal axis and an element of magnetic material extending in the direction of the longitudinal axis and having a periodically varying dimension in a direction perpendicular to the longitudinal axis, and a second member (10) movable relatively to the first member along the longitudinal axis and comprising means to induce a magnetic field in the element. The position detector analyses characteristic variations in the magnetic field to determine the position of the first member relative to the second member.

Abstract: The invention relates to abrasive flap discs which are used for a variety of finishing, grinding and polishing operations, particularly on welded fabrications. The present invention provides an abrasive flap disc (20) comprising a backing plate (11), an annular array of flaps (12) of abrasive material arranged on the backing plate (11) and bonded thereto along the lower most edge of each flap (12), wherein each flap (12), at least in a radially outer region is substantially spaced from each adjacent flap (12) such that the flaps (12) have freedom to flex and conform to an underlying surface in use.

Abstract: A method and apparatus for measuring the electrical efficacy of one or more battery cells for use in an uninterruptable power supply are disclosed. The efficacy is determined by making use of the ripple current which flows in the battery cells when in use in the uninterruptable power supply. Simultaneous measurement, for example, of the ripple current and a corresponding voltage component enables the internal impedance of a battery cell to be determined, the impedance acting as an indicator of electrical efficacy.

Abstract: Control apparatus for an electric vehicle is described, the control apparatus comprising input means operable to generate a first signal indicative of a component of a desired motion of the vehicle and a second signal independently indicative of said component; an electric motor arranged to drive a wheel of the vehicle; a controller arranged to control the motor according to said first signal; and means for generating a signal indicative of a voltage across windings of the motor, the controller further including: means for calculating a quantity indicative of a nominal expected voltage across said windings according to said second signal; means for comparing said voltage with said expected voltage; and means for generating an error signal in response to said voltage and expected voltage differing by more than a predetermined amount. A corresponding method of controlling an electric vehicle is also described.

Abstract: Brake control apparatus and includes an electric motor arranged to drive a wheel and a brake operable to apply a braking force to inhibit the rotation of the wheel. An input signal indicative of a desired angular velocity of the wheel is provided to the control. The current flowing through the electric motor is monitored and a monitoring signal is provided. The power to the electric motor is controlled in response to the input signal by generating a control voltage. After setting the control voltage to zero the brake applies the braking force at a braking time. The braking time may be determined according to the magnitude of the monitoring signal when the control voltage is set to zero, according to the rate of change of the monitoring signal, or according to the polarity of the monitoring signal. An electric vehicle using the brake control apparatus is also disclosed, as is a method of controlling a brake for applying a braking force to inhibit the rotation of a wheel driven by an electric motor.

Abstract: A method of producing a multi-apertured component for providing a predetermined fluid flow includes the steps of dividing the component into regions in which the apertures are to be formed, forming a portion of the apertures in a first region in accordance with assumed parameters, measuring the fluid flow through the apertures and correcting, if necessary, the assumed parameters for the apertures in the first region to provide the fluid flow required through the first region and the assumed parameters for each of the other regions, and completing drilling of the apertures in the first region and in each of the other regions.

Abstract: A plurality of apertures are formed in a component e.g. by a laser drilling method, the finished component being intended to have a fluid flow through the apertures which is as close as possible to a predetermined value. After one aperture or a series of apertures has been formed, the fluid flow therethrough is measured and is compared with the predetermined value. The process parameters are then adjusted in the formation of the next aperature or series of apertures in acordance with the comparison.