Inductively-Powered Power Transfer System With One Or More Independently Controllable Loads
First Claim
1. A method of controlling an inductively-powered operating unit for use in association with an inductive power transfer (IPT) system, the method comprising the steps of:
- frequency modulating a current in a primary conductor circuit of the IPT system; and
, in the operating unit;
(a) detecting a frequency of current in the primary conductor circuit;
(b) generating a local oscillator signal;
(c) using the local oscillator signal to detect a change in the frequency of the primary circuit current; and
(d) using the detected change to control the operating unit.
1 Assignment
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Accused Products
Abstract
The present invention provides a system for controlling one or more operating unites in an inductive power transfer (IPT) system. Each operating unit includes a pick-up coil that takes power from a primary conductor or track over an air gap. The operating unit is controlled by frequency modulating the primary conductor power supply to send a control instruction which is decoded by the operating unit. The instruction is decoded by generating a signal using a local oscillator in the operating unit and using the signal to detect changes in the frequency of the current in the primary conductor. Such a system can be used, for example, to control inductively powered road-studs that include a light source for controlling traffic on a roadway. A narrow band modulated data transmission system and method for controlling an operating unit are also provided.
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Citations
55 Claims
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1. A method of controlling an inductively-powered operating unit for use in association with an inductive power transfer (IPT) system, the method comprising the steps of:
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frequency modulating a current in a primary conductor circuit of the IPT system; and
, in the operating unit;(a) detecting a frequency of current in the primary conductor circuit; (b) generating a local oscillator signal; (c) using the local oscillator signal to detect a change in the frequency of the primary circuit current; and (d) using the detected change to control the operating unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 53)
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14. A controlled inductively powered unit for use in association with an inductive power transfer (IPT) system having a primary conductor circuit with a modulated current, the operating unit comprising:
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a signal detection unit operable to detect a frequency of current in the primary conductor circuit; a local oscillator unit operable to provide a local oscillator signal; a signal processing unit operable to use the local oscillator signal to detect a change in the frequency of the primary conductor current; and a control unit operable to control the operating unit dependent on the detected change. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 54)
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26. A roadway lighting system comprising a plurality of separately controllable road-studs, each road-stud comprising:
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a light emitting element and being powered inductively via a primary conductor circuit buried under or in a roadway, a frequency modulation unit adapted to modulate current in the primary conductor circuit, and wherein each controllable road-stud comprises; a signal detection unit operable to detect the frequency of current in the primary conductor circuit; a local oscillator unit operable to provide a local oscillator signal; a signal processing unit adapted to use the local oscillator signal to detect a change in the frequency of the primary conductor current; and a control unit operable to control the operating unit dependent on the detected change. - View Dependent Claims (27, 28, 29)
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30. A narrow band modulated data transmission system for controlling one or more light emitting units, the system comprising:
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a transmission unit operable to transmit a modulated signal, and each of the one or more light emitting units comprising; a reception unit tuned to receive the modulated signal, a detection unit operable to detect the data present in the received signal, and wherein the total power to operate the light emitting unit is derived from the received signal. - View Dependent Claims (31)
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32. A method of controlling one or more light emitting units comprising the steps of:
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transmitting a narrow band modulated signal; receiving the modulated signal at a light emitting unit; detecting a data present in the received signal; controlling the light emitting unit dependent on the detected data; and using the received signal to provide the total power to operate the light emitting unit. - View Dependent Claims (33)
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34. A method of controlling traffic on a road, the method including the steps of:
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incorporating a road way lighting system comprising a plurality of separately controllable road-studs into or onto the road, each road-stud comprising a light emitting element and being powered inductively via a primary conductor circuit buried under or in a roadway, a frequency modulation unit adapted to modulate current in the primary conductor circuit, and wherein each controllable road-stud comprises;
a signal detection unit operable to detect a frequency of current in the primary conductor circuit;
a local oscillator unit operable to provide providing a local oscillator signal;
a signal processing unit adapted to use the local oscillator signal to detect a change in the frequency of the primary conductor current; and
a control unit operable to control the operating unit dependent on the detected change, andmodulating the frequency of current in the primary conductor circuit to initiate a pattern of operation of each controllable road-stud such that the plurality of road-studs provide a message to users of the road. - View Dependent Claims (35, 36, 37, 55)
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38. A controllable road-stud system comprising:
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a power supply for generating a substantially sinewave current in a primary conductive path wherein a frequency of the current can be modulated, a plurality of active nodes tuned to the power supply frequency located at specific points along the primary conductive path, a road-stud tuned to the power supply frequency located in close proximity to each of the active nodes, each road-stud including; a pick-up coil with a tuning capacitor, a rectification unit operable to produce a DC source of power, a control unit operable to control a power flow from the primary conductive path to the road-stud, a light source in series with a controllable switch connected across the DC source of power and active to switch the light source on or off, a signal detection unit operable to detect a frequency of the current in the primary conductive path or the current in the pick-up coil, a unit operable to produce a local oscillator signal at a known frequency relative to the detected frequency, a tracking unit operable to track the local oscillator signal frequency against variations in frequency or components unit operable to produce signal representative of the difference frequency between the detected frequency and the frequency of the local oscillator signal, a counting unit operable to count a number of cycles of the detected frequency in one cycle of the difference signal, a comparator unit operable to determine whether the counted number of cycles is greater or less than a comparison fixed number to provide a decoded output, and a processor unit operable to control the light source on the road-stud according to the decoded output. - View Dependent Claims (41, 42)
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39. A controllable road-stud for use in association with an inductive power transfer (IPT) system having a primary conductive path with a frequency modulated current, the road-stud comprising:
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a signal producing device operable to produce a local oscillator signal in the road-stud of known accuracy with respect to an unmodulated frequency of the current in the track, a unit operable to use the local oscillator signal to detect changes in the frequency of the current in the primary conductive path, a conversion unit operable to convert the detected changes to digital form to produce binary output representative of the modulation of the frequency of the current in the primary conductive path, a processing device for interpreting the binary output and a driving switch for switching a light source powered by the road-stud on or off as appropriate. - View Dependent Claims (40, 43, 44, 45, 46)
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47-51. -51. (canceled)
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52. A system for controlling one or more light emitting units, the system including comprising:
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a narrow band modulated data transmission system for controlling one or more light emitting units, the data transmission system including comprising; a transmission unit operable to transmit a modulated signal, and the or each of the one or more light emitting units comprising; a reception unit tuned to receive the modulated signal, and a detection unit operable to detect the data present in the received signal, and an IPT system, the IPT system providing power to the light emitting unit.
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Specification