GB2554962A

GB2554962A - Common choke

Info

Publication number: GB2554962A
Application number: GB1704251.6A
Authority: GB
Inventors: Wang David; He Selva
Original assignee: Tridonic GmbH and Co KG
Current assignee: Tridonic GmbH and Co KG
Priority date: 2016-10-12
Filing date: 2017-03-17
Publication date: 2018-04-18
Also published as: GB201704251D0

Abstract

A choke comprises a winding [12] around a magnetic core, wherein the winding insulation is thicker than that of an ordinary enamelled wire. The insulation may be a double or triple insulated wire. The choke may be equidistantly divided into four channels with a channel located at either end of the magnetic core. The winding [12] may be in multiple channels. The channels 1-4 may have corresponding windings 1-4. The choke may have an asymmetric winding in that at least two of the wire turns of windings 1-4 are different. Winding 1 may be connected in series with winding 2 and winding 3 may be connected in series with winding 4. Similarly, winding 2 may be connected in series with winding 3 and winding 1 may be connected in series to winding 4. The choke may be used as an EMI filter.

Description

(71) Applicant(s):

Tridonic GmbH & Co KG (Incorporated in Austria)

Farbergasse 15, 6851 Dornbirn, Austria (51) INT CL:

H01F5/02 (2006.01) (56) Documents Cited:

CN 105244090 A

US 5227745 A

JPH0453108

JPH04112508

JPH0496816

JPH0499517

JP H0362506

H01F5/06 (2006.01)

TW 201115599 A US 20080100409 A

Wikipedia, 2017, Magnet Wire, wikipedia.org, [online], Available from: https://en.wikipedia.org/wiki/ Magnet_wire [Accessed 9 August 2017].

(72) Inventor(s):

David Wang Selva He (58) Field of Search:

INT CL H01F Other: EPODOC, WPI.

(74) Agent and/or Address for Service:

Zumtobel Group IP Manangement

Alexander Barth, Hochster St. 8, 6850 Dornbirn,

Austria (54) Title of the Invention: Common choke

Abstract Title: Common choke with thick insulation winding (57) A choke comprises a winding [12] around a magnetic core, wherein the winding insulation is thicker than that of an ordinary enamelled wire. The insulation may be a double or triple insulated wire. The choke may be equidistantly divided into four channels with a channel located at either end of the magnetic core. The winding [12] may be in multiple channels. The channels 1-4 may have corresponding windings 1-4. The choke may have an asymmetric winding in that at least two of the wire turns of windings 1-4 are different. Winding 1 may be connected in series with winding 2 and winding 3 may be connected in series with winding 4. Similarly, winding 2 may be connected in series with winding 3 and winding 1 may be connected in series to winding 4. The choke may be used as an EMI filter.

At least some of the priority details shown above were added after the date of filing of the application.

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

Formulae in the printed specification were reproduced from drawings submitted after the date of filing, in accordance with Rule 20(13) of the Patents Rules 1995

Fig·²

Common choke

The present invention relates to a common choke for EMI filtering.

Technical area

In order to save energy, today energy saving lamps are used. With the introduction of efficient inorganic light emitting diodes (LED) as potential light sources there is also a demand for energy saving lamps using LED which have the ability to be dimmed. In recent time there are developments to establish and use organic LED (OLED) as a light source for lighting. Such LED and OLED are typically driven by electronic control gear which comprise an EMI filter including a filter choke.

State of the art

WO9614644A1 concerns a filter choke having a coil core (14) which comprises a straight core section and two coils (Wl, W2) which are disposed thereon, have identical inductance and are wound in opposite senses. The coils (Wl, W2) are disposed adjacent each other on the straight core section and a spacing for forming leakage inductance is provided between the two coils (Wl, W2) in the longitudinal direction of the straight core section.

Today it is common to use two or more chokes for common mode and differential mode noise filtering. Such existing solutions lead to higher cost and more space. But integration of both functions into one component is difficult as differential mode interference is hard to be reduced by application of a common choke.

The present invention seeks to provide a further improvement of filter chokes.

The present invention relates to a common choke, comprising a magnetic core and a winding winded on the magnetic core. The winding is winded by a wire of which an insulation is thicker than an insulation of an ordinary enameled wire.

The wire of which an insulation may be thicker than an insulation of an ordinary enameled wire comprises a double insulated wire or a triple insulated wire.

The winding of the common choke may be winded in multiple channels.

The common choke may be winded in multiple channels. According to the length of the magnetic core, the common choke may be equidistantly divided into four channels, a first channel, a second channel, a third channel and a fourth channel. The first channel and the fourth channel may be respectively located at the two ends of the magnetic core. The second channel may be located between the first channel and the third channel, the third channel is located between the second channel and the fourth channel.

The common choke may have an asymmetric winding structure.

A first winding may be arranged in the first channel, a second winding may be arranged in the second channel, a third winding may be arranged in the third channel, a fourth winding may be arranged in the fourth channel. The asymmetric winding structure may come with the feature that at least two of wire turns of the first winding are different to the wire turns of the fourth winding.

At least two of turns of the first winding to the fourth winding four are different comprising: first winding and third winding may have same turns, second winding and fourth winding may have different turns; or first winding and third winding may have different turns, second winding and fourth winding may have same turns.

First winding may be connected in series with second winding, third winding in series with fourth winding; or second winding may be connected in series with third winding, first winding in series with fourth winding.

The common choke may be used for EMI filtering or function as EMI filter. The common choke may act as filter for both differential mode and common mode interferences.

As an aid to understanding the invention, a preferred embodiment thereof will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which:

Figure 1 shows a first embodiment of a common choke of the invention; and

Figure 2 shows a second embodiment of a common choke of the invention.

Figure 1 shows a common choke, comprising a magnetic core, a bobbin 11 surrounding the magnetic core and a winding 12 winded on the magnetic core. The winding is winded by a wire of which an insulation is thicker than an insulation of an ordinary enameled wire.

The winding of the common choke may be winded in multiple channels.

The common choke may be winded in multiple channels. According to the length of the magnetic core, the common choke may be equidistantly divided into four channels, a first channel, a second channel, a third channel and a fourth channel. The first channel and the fourth channel may be respectively located at the two ends of the bobbin and the magnetic core. The second channel may be located between the first channel and the third channel, the third channel is located between the second channel and the fourth channel.

The common choke may have an asymmetric winding structure.

Fig. 2 shows an comparison between a wire 21 with an insulation of an ordinary enameled wire and a wire 22 which is a wire of which an insulation is thicker than an insulation of an ordinary enameled wire.

The common choke according to the present invention offers an improvement of the noise filter bandwidth by reduction of the parasitic capacitances (except parasitic capacitance between winding 2 and winding 3). In addition the invention offers the advantage of an increase of leakage inductance and of the parasitic capacitance between winding 2 and winding 3 which leads to an improvement of the filter differential mode interference.

The common choke according to the present invention may comprise an E-core or an I-core as magnetic core.

Claims

Claims:

1. A common choke, comprising a magnetic core and a winding winded on the magnetic core, characterized in that, the winding is winded by a wire of which an insulation is thicker than an insulation of an ordinary enameled wire.

2. The common choke according to claim 1, characterized in that, the wire of which an insulation is thicker than an insulation of an ordinary enameled wire comprises a double insulated wire or a triple insulated wire.

3. The common choke according to claim 2, characterized in that, the winding of the common choke is winded in multiple channels.

4. The common choke according to claim 3, characterized in that, the winding of the common choke is winded in multiple channels comprises: according to the length of the magnetic core, the common choke is equidistantly divided into 4 channels, channel 1, channel 2, channel 3 and channel 4; the channel 1 and the channel 4 are respectively located at the two ends of the magnetic core, the channel 2 is located between the channel 1 and the channel 3, the channel 3 is located between the channel 2 and the channel 4.

5. The common choke according to claim 4, characterized in that, the common choke has an asymmetric winding structure.

6. The common choke according to claim 5, characterized in that, a winding 1 in the channel 1, a winding 2 in the channel 2, a winding 3 in the channel 3, a winding 4 in the channel 4, the asymmetric winding structure comprises: at least two of wire turns of the winding 1 to winding 4 are different.

7. The common choke according to claim 6, characterized in that, at least two of turns of winding 1-winding 4 are different comprising: winding 1 and winding 3 have same turns, winding 2 and winding 4 have different turns; or winding 1 and winding 3 have different turns, winding 2 and winding 4 have same turns.

8. The common choke according to claim 4, characterized in that, winding 1 series with winding 2, winding 3 series with winding 4; or winding 2 series with winding 3, winding 1 series with winding 4.

9. The common choke according to anyone of claim 1 to claim 8, characterized in that, the common choke is used for EMI filter.

Intellectual

Property

Office

Application No: GB1704251.6