EP0700574B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Power coupling
Assignee: ERA Patents Ltd
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Filing: 1994-05-19
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Granted: 1997-07-30
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Expires: 2014-05-19
Abstract
Abstract A power coupling system includes a source unit (1) which is to be connected to a power supply. The source unit (1) includes a first winding (P). A load unit (2) includes a second winding (S). Power is inductively coupled from the first winding to the second winding. The source unit (1) and load unit (2) are readily separable. The second winding (S) is connected in a resonant circuit. An AC voltage applied to the first winding (P) is tuned to the resonant frequency of the load circuit including the secondary winding leakage inductance. The source unit may be tuned automatically to the resonant frequency and may include a phase-locked loop responsive to voltages and currents in the source and the load.
Inventors
- 👤 Donald Austin Grant Pedder
- 👤 Andrew John Skinner
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 19:43
CPC Classifications
H; H01; H01F; H01F38/00; H01F38/14; B; B60; B60L; B60L53/00; B60L53/10; B60L53/12; B60L53/122; B60L53/124; B60L53/20; B60L53/22; B60L53/30; B60L53/34; H02; H02J; H02J50/00; H02J50/10; H02J50/12; H02J50/40; H02J50/402; H02J50/70; H02J7/00; H02J7/60; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; B60L2200/00; B60L2200/26; B60L2200/34; B60L2210/00; B60L2210/30; B60L2210/40; B60L2240/00; B60L2240/40; B60L2240/54; B60L2240/547; B60L2240/549; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/70; Y02T10/7072; Y02T10/72; Y02T90/00; Y02T90/10; Y02T90/12; Y02T90/14
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
121 words
A power coupling system comprising a source unit (1) arranged to be connected to a power supply and including a first winding (P) and a load unit (2) including a second winding (S) connected in a resonant circuit, in use power being inductively coupled from the first winding to the second winding, and the source unit (1) and load unit (2) being readily separable, characterised by a variable tuning circuit arranged to control the frequency of the voltage applied to the first winding in dependence upon the resonant frequency of the load circuit including the secondary winding leakage inductance, so that an AC voltage applied to the first winding (P) is tuned to the said resonant frequency of the load circuit.
Claim 2
Dependent Claim
50 words
A power coupling system according to claim 1, in which the tuning circuit (6) includes a phase-locked loop responsive to the phase difference between the source unit voltage and the load unit current as referred to the source unit and arranged to control the frequency of the AC voltage accordingly.
Claim 3
Dependent Claim
27 words
A power coupling system according to claim 2, in which the source unit (1) includes an inverter (5) switched at a frequency determined by the tuning circuit.
Claim 4
Dependent Claim
41 words
A power coupling system according to claim 3, in which each arm of the inverter includes a field-effect transistor (FET) (Q1, Q2, Fig 8), each FET being arranged to be turned on when the voltage across the FET is substantially zero.
Claim 5
Dependent Claim
45 words
A power coupling system according to any one of claims 1 to 4, in which the tuning circuit (6) is arranged to drive the source unit circuit at a high frequency in the absence of a load,and to reduce the frequency as the load approaches.
Claim 6
Dependent Claim
61 words
A power coupling system according to any one of the preceding claims, in which one winding (P) is formed on a core (4) having a re-entrant portion and the core (9) for the other winding has at least one part which is dimensioned to fit within the re-entrant portion of the core as the load and source units are brought together.
Claim 7
Dependent Claim
23 words
A power coupling system according to claim 6, in which both the source core (4) and the load core (9) are generally U-shaped.
Claim 8
Dependent Claim
38 words
A power coupling system according to claim 6, in which both the source core (93) and the load core (94) are generally cylindrical, with one of the cores (93) including a generally annular extension defining the re-entrant portion.
Claim 9
Dependent Claim
38 words
A power coupling system according to any one of the preceding claims, in which one of the source and load windings (P,S) is positioned around a slot for receiving the other of the source and load windings (P,S).
Claim 10
Dependent Claim
79 words
A power coupling system according to any one of the preceding claims, in which the resonant circuit in the load unit (2) includes a switched component (R1. Fig. 10) which, when connected in the resonant circuit, changes the resonant frequency of the circuit, in use, the source unit (1) detecting the change in resonant frequency of the load unit (2), the switching of the switch component thereby being used to transmit a signal from the load to the source.
Claim 11
Dependent Claim
37 words
A power coupling system according to claim 10, in which the switch (Q1, Q2, Fig. 11) for the switched component is responsive to a pulsed data stream, the load unit thereby transmitting data to the source unit.
Claim 12
Dependent Claim
37 words
A power coupling system according to any one of claims 1 to 11, in which the tuning circuit (6) includes a differentiator arranged to detect the phase of a quasi-sinusoidal component of the source unit winding current.
Claim 13
Dependent Claim
28 words
A power coupling system according to any one of the preceding claims, in which the source unit (1) and load unit (2) are sealed within respective water-tight housings.
Claim 14
Dependent Claim
31 words
A power coupling system according to any one of the preceding claims in which one of the load and source units (2,1) is mounted for rotation and the other is fixed.
Claim 15
Dependent Claim
29 words
A power coupling system according to claim 14 in which one of the windings (P,S) is formed on a bobbin-shaped core which in use rotates about its central axis.
Claim 16
Dependent Claim
16 words
A power coupling system according to claim 15, in which the other core is generally U-shaped.
Claim 17
Dependent Claim
51 words
A power coupling system according to any one of claims 1 to 13, in which the load units (2) is mounted on a first member and the source unit (1) is mounted on a second member, and in which the first and second members are slidable with respect to each other.
Claim 18
Dependent Claim
65 words
A power coupling system comprising a source unit (1) and a plurality of load units (2) arranged to be coupled individually to the source unit (1), the source unit (1) and load unit (2) together forming a system in accordance with any one of the preceding claims, different load units (2) being individually coupled to the source unit (1) to provide different respective drive voltages.
Claim 19
Dependent Claim
41 words
A system according to claim 14, including a plurality of source units (1), each source unit (1) being arranged to be connected to a different respective power supply and to generate a common standard coupling field for the load units (2).
Claim 20
Dependent Claim
82 words
A power coupling system comprising a plurality of source units (1) and load unit (2) arranged to be coupled to any one of the source units (1), any one of the source units (1) and the load unit (2) together forming a system in accordance with any one of claims 1 to 17, the plurality of source units (1) being arranged to be connected to different respective power supplies, and to generate a common standard coupling field for the load unit (2).
Claim 21
Independent Claim
60 words
A method of coupling power inductively from a source to a load including bringing separable respective source and load units (1,2) into proximity, the load winding (5) being connected in a resonant circuit characterised by tuning automatically the frequency of operation of the source unit to match the resonant frequency of the load including the load winding (5) leakage inductance.
References Cited (Backward Citations)
No citation records indexed.
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