Abstract: A pick-up is provided for an Inductively Coupled Power Transfer (ICPT) system having a parallel tuned resonant pick-up circuit. The pick-up has a plurality of independently controllable power supply outputs. This allows a first output to supply a high voltage load (e.g. 300V-550V) and one or more additional outputs for supplying other loads such as control circuitry which may only require 24V. The one or more additional outputs may be supplied via a current transformer connected in series with the resonant pick-up circuit. Control for each output may be achieved by partially or completely decoupling the pick-up from a primary conductive path of the ICPT system.

Abstract: A starting circuit for an induction motor is provided whereby a stationary rotor flux is established then a stored charge supplied to a motor winding in order to provide a starting torque. Before applying a mains power supply to the motor after the starting torque has been applied, a back EMF is sensed, directly or indirectly, to provide an indication that the rotor is turning before the mains supply is connected to the motor. This provides a reliable and simple method for ensuring that a mains supply may be safely connected to the motor.

Abstract: A starting circuit for an induction motor is provided whereby a stationary rotor flux is established then a stored charge supplied to a motor winding in order to provide a starting torque. Before applying a mains power supply to the motor after the starting torque has been applied, a back EMF is sensed, directly or indirectly, to provide an indication that the rotor is turning before the mains supply is connected to the motor. This provides a reliable and simple method for ensuring that a mains supply may be safely connected to the motor.

Abstract: A primary inductive track or path 450 for a resonant inductive power distribution system is made up from a number of modules 453, each supplied as a pre-built and substantially pre-tuned segment of the track. These modules have more than one capacitor 456, 457 and more than one inductance 458, 459 (generally, the inductance is the intrinsic inductance of the length of track) and each capacitor and adjacent inductor is capable of resonating at its own native frequency. A zero-inductance cable 452, carrying a small fraction of the circulating resonant current (comprising a mis-match or an error current), directly connects the capacitors at poles having equal polarity and tends to constrain the system limiting possible frequencies of resonance.

Abstract: A loosely coupled inductive power transfer system suitable for transferring power to a mobile conveyer platform or a vehicle has pick-up coils wound on flux concentrator(s). One or more large flat horizontal ferrite cores 607, 608 are used to concentrate the horizontal component of magnetic flux from an extended volume into one or more secondary or pick-up coils 613. Each shock-resistant core comprises an array of many individual strips of ferrite held in close contact. One, more usually two, or perhaps more resonant pick-up windings are wound about each core and each winding has a shorting switch (within 602, 603 . . . ) placed across it. A controller 601 connects a controlled output voltage on to an output bus 605, 606 from the best-placed pick-up winding on any one core at any moment, while holding the others in a shorted hence inactive state.

Abstract: This resonant power supply produces a varying magnetic field from a resonant inductor. Two active switches drive, but remain outside, a resonant circuit, also including resonant capacitor. A phase-splitting transformer provides, via a decoupling inductor, one connection for a power supply; the return is through the active switches, which are either off or are from time to time driven alternately by the controller so as to maintain the resonant current in the resonant circuit. Applications include induction heating and induction hobs for cooking, and also a power source for inductively powered vehicles (or other inductively powered devices) adjacent to an inductive pathway.

Abstract: A contactless inductive power distribution system operating at 10 KHz has a self tuning resonant power supply connected to a resonant primary conductive path comprising a pair of parallel litz wire conductors each encapsulated within an insulated sheath and supported on a structural monorail beam on which a plurality of electric vehicles can run. Each vehicle has an electric motor capable of deriving power from a resonant pick-up coil wound on a ferrite core mounted on the vehicle in close proximity to the primary conductors. Each vehicle also has switching means capable of preventing a lightly loaded vehicle from presenting a reduced load to the resonant primary. In one version this comprises an isolating coil having a switch to switch the coil between an open circuit and a short circuit, so that when the switch is switched from one state to another state the power coupled between the primary conductive path and the pick-up coil is changed.

Abstract: Power supply apparatus is disclosed which can be configured as a power line filter or an uninterruptible power supply having a battery test on load capability. It comprises an input reversible rectifier connectable between an AC supply and a high voltage internal DC bus, a second reversible rectifier interconnecting storage batteries to the high voltage DC bus, and an output module supplying a desired DC output or an AC output. In use the voltage on the internal DC bus is maintained at a greater level than that of (a) the instantaneous repetitive peak of the incoming voltage, and (b) the peak battery storage voltage. Battery test means is provided by allowing the dumping of the charge stored within the storage batteries for a certain period at the maximum available rate into the internal bus and back into the AC supply through the said reversible rectifiers; meanwhile observing the extent of the battery voatage drop so caused.

Abstract: A method and apparatus is shown to control both the motor terminal current to vary in exact proportion as the motor shaft torque varies for any given excitation frequency. This obviates the need for ancillary motor speed control and prevents voltage boosting at low speeds from resulting in excessive motor losses for no load conditions. A motor is powered from an inverter, the inverter providing an output voltage with independent control of amplitude and frequency. A frequency signal is fed directly to the inverter from a frequency input, the frequency input also being connected to a multiplier. The multiplier provides the amplitude signal for the inverter based on the product of the input frequency and motor current.

Abstract: A method of tightening and a tightening system using the method. The method includes the steps of providing pulse with modulated waveforms from an inverter, driving an AC induction motor by the waveforms in a highspeed low torque mode or a low speed high torque mode or causing the motor to stop, by controlling the inverter to vary the pulse width of the waveforms, and driving a fastening device by the AC induction motor.

Abstract: A method and apparatus for governing a generator which generator comprises micro-hydropower generating equipment usable in run-of-the-stream situations. A plurality of dump loads are associated with the electrical output of the generator and changes in frequency of the output phase voltage of the generator are detected. The dump loads are switched into or out of association with the generator in response to the frequency changes so as to cause substantially compensating frequency changes. The rate at which the compensating frequency changes occurs are damped desirably by use of a flywheel.

Abstract: An impact wrench having an adaptive control system for determining the yield point or some similarly significant point of a fastener assembly by detecting a signal representative of the peak deceleration of the hammer, one embodiment of which is the peak recoil value of the hammer after impacting with the anvil of the wrench, and a signal representative of the angular displacement of the output shaft of the wrench. Yield of the fastener is determined when the respective magnitudes of successive deceleration signals do not exceed the magnitude of a previously stored maximum deceleration signal by a predetermined fixed amount. Upon attaining the yield point or other similarly significant point, the wrench may be allowed to rotate the fastener an additional preselected number of degrees before shutting off.

Abstract: A self-contained impact wrench having an adaptive control system for determining the yield point or some similarly significant tightened condition of a fastener assembly by detecting a signal representative of the forward rotation angle of the fastener assembly is disclosed. One embodiment utilizes a computed signal of time over a fixed interval of forward rotation angle, as an estimate of the torque applied by the impact wrench, and the torque estimate vs. rotation angle curve is differentiated to obtain the gradient thereof. Successive gradient values are stored and compared, and when the present gradient value has attained a predetermined relationship relative to a stored value of a gradient in a tightening region of the curve, further tightening of the fastener assembly is discontinued. This ensures that the yield point or other similarly significant tightened condition of the assembly has been reached.

Abstract: A triangle waveform having substantially linearly sloped, gradually increasing and decreasing edges and having a frequency nf is generated from an n-phase sine wave signal, each phase having a fundamental frequency f. A segment of any of the n-phases of the sine wave is detected when that segment is within a predetermined angular amount from a reference crossing level, such as the zero crossing of the sine wave signal. Successive ones of the detected segments are selected to synthesize the triangle waveform. In the preferred use of this invention, the triangle waveform is compared to a reference signal, such as the sine wave signal from which the triangle waveform is generated, this reference signal having a controllable frequency and amplitude. Pulse transitions are generated at the intersection of the triangle waveform and each of the respective phases of the reference signal.

Abstract: An impact wrench having an adaptive control system for determining the yield point or some similarly significant point of a fastener assembly by detecting a signal representative of the peak deceleration of the hammer, one embodiment of which is the peak recoil value of the hammer after impacting with the anvil of the wrench, and a signal representative of the angular displacement of the output shaft of the wrench. Yield of the fastener is determined when the respective magnitudes of successive deceleration signals do not exceed the magnitude of a previously stored maximum deceleration signal by a predetermined fixed amount. Upon attaining the yield point or other similarly significant point, the wrench may be allowed to rotate the fastener an additional preselected number of degrees before shutting off.

Abstract: A meter for determining stiffness or torque gradient including, in one embodiment, a deflectable coupling connected between an output shaft and a power input shaft, sensing means for developing two separate series of signals representative of the displacement of the input and output shafts respectively, a comparator for determining from the two series of signals a function of the stiffness or torque gradient and, in another embodiment, including a single shaft having an input end and an output end, transducer means associated with the shaft for developing a signal representative of the torque being applied through the shaft, sensing means for developing a signal representative of the displacement of the shaft, and comparator means for determining from the two signals a function of the stiffness or torque gradient.

Abstract: A method of counting small parts by feeding the parts in bulk to discharge a stream of parts into a separating region leading to a plurality of outlet channels, the separating region including spaced rods capable of spatially distributing the parts in a random manner over the outlet channels as the parts fall through the separating region and cascade from rod to rod, counting the number of parts passing through each outlet channel and adding together the corrected numbers of parts passing through all the channels.

Abstract: The preferred embodiments of the invention disclosed herein relate to a tightening system comprising a wrench for rotating and applying torque to a fastener system, means for developing a signal representative of the torque being applied and means for developing a signal representative of the rotation. A control system is operatively associated with the wrench for determining which of the two signals is increasing faster. If the torque signal is increasing faster than the rotation signal, the control system modifies the rotation signal by increasing it until it corresponds to the torque signal, but cannot decrease the modified rotation signal when the increase of the torque signal is less than the increase of the rotation signal. When the increase of the torque signal decreases relative to the modified rotation signal, the control system develops a decision-making signal which is processed to develop a control signal when a yield point of the fastener system is detected.

Abstract: The preferred embodiments of the invention disclosed herein relate to a tightening system comprising a wrench for rotating and applying torque to a fastener system, means for developing a signal representative of the torque being applied and means for developing a signal representative of the rotation. The signals are compared and the total rotation signal is increased when the torque signal is increasing at a faster rate than the rotation signal so that the rotation signal corresponds to the torque signal. When the torque signal decreases relative to the rotation signal the rotation signal cannot decrease and a decision-making signal is developed which is processed to develop a control signal when a yield point of the fastener system is detected.

Abstract: A meter for determining stiffness or torque gradient including, in one embodiment, a deflectable coupling connected between an output shaft and a power input shaft, sensing means for developing two separate series of signals representative of the displacement of the input and output shafts respectively, a comparator for determining from the two series of signals a function of the stiffness or torque gradient and, in another embodiment, including a single shaft having an input end and an output end, transducer means associated with the shaft for developing a signal representative of the torque being applied through the shaft, sensing means for developing a signal representative of the displacement of the shaft, and comparator means for determining from the two signals a function of the stiffness or torque gradient.