Non-Contact Power Transmission Device

• US 20070252441A1
• Filed: 08/26/2005
• Published: 11/01/2007
• Est. Priority Date: 08/27/2004
• Status: Active Grant

• Current Assignee: Hokushin Denki Company Limited
• Original Assignee: Hokushin Denki Company Limited
• Inventors: Yamauchi, Yukinaga, Hirase, Hidekazu
• Granted Patent: US 7,782,633 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/33571 Half-bridge at primary side of an isolation transformer
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A non-contact power transmission device, which is capable of efficiently reducing the device size and reducing unnecessary radiation of a harmonic component from a primary side coil, is provided. The non-contact power transmission device which includes a primary side unit and a secondary side unit which house a primary side and a secondary side of a coupling transformer individually and can be separated from each other, a capacitor C₁ which resonates with a primary side coil L₁ is connected to the primary side coil L₁ in series so that a primary side series resonance circuit is formed, an L-shaped resonance circuit which has a coil L₃ and a capacitor C₇ resonating with the coil L₃ is inserted between the primary side series resonance circuit and a driving circuit, and the L-shaped resonance circuit is connected to the primary side series resonance circuit in series.

Claims

1. A non-contact power transmission device comprising a primary side unit and a secondary side unit which house a primary side and a secondary side of a coupling transformer individually and can be separated from each other, wherein

a capacitor which resonates with a primary side coil is connected to the primary side coil in series so that a primary side series resonance circuit is formed, an L-shaped resonance circuit having a coil and a capacitor resonating with the coil is inserted between the primary side series resonance circuit and a driving circuit, and the L-shaped resonance circuit is connected to the primary side series resonance circuit in series.

2. The non-contact power transmission device according to claim 1,

wherein a capacitor which resonates with a secondary side coil is connected to the secondary side coil so that a secondary side series resonance circuit is formed.

3. The non-contact power transmission device according to claim 1,

wherein the L-shaped resonance circuit composes a filter.

4. The non-contact power transmission device according to claim 3,

wherein a resonance frequency of the L-shaped resonance circuit is made to be lower than a driving frequency of the driving circuit by 5% to 25%.

5. The non-contact power transmission device according to claim 1,

wherein a resonance frequency of the primary side series resonance circuit is adjusted to the driving frequency of the driving circuit.

6. The non-contact power transmission device according to claim 2,

wherein a resonance frequency of the secondary side series resonance circuit is adjusted to the driving frequency of the driving circuit.

7. The non-contact power transmission device according to claim 1,

wherein in the primary side series resonance circuit, the other capacitors are connected to the primary side coil in parallel.

8. The non-contact power transmission device according to claim 1,

wherein the L-shaped resonance circuit composes an impedance matching circuit.