EP1902451B1 - Swinging choke for light applications - Google Patents

Description

The present invention relates to vibration chokes and in particular vibration chokes used in electronic ballasts for igniting and operating bulbs, such. As fluorescent tubes or gas discharge lamps, can be used.

Such oscillating chokes can be used to high voltage pulses in a resonant circuit for igniting a light source, such. As fluorescent tubes, gas discharge lamps or arc lamps to produce. The ignition voltage can be several 1000 volts _ss in the case of fluorescent tubes.

Swing chokes, which are suitable for this purpose, z. In the international patent application WO 03/007318 A2 described. Therein a vibrating choke with a symmetrical double E-core is disclosed.

US 4 419 814 A discloses a swing throttle according to the preamble of claim 1.

When operating such lamps, it is desirable that at least one further voltage in the low-voltage range is available for one or more auxiliary circuits. For example, it is desirable to heat at least one of the electrodes of the illuminant to improve the efficiency, lifetime and efficiency of the lamp. For heating, voltages are typically required in the range of 5 to 15 volts, which must be maintained relatively accurately, otherwise parts of the heater could be damaged, or the life of the lamp could be reduced.

It is therefore an object of this invention to provide a swinging choke which can be used on the one hand for the lighting circuit of a lighting means and on the other hand reliably supplies a voltage usable for an auxiliary circuit such as a heating circuit. It is a further object of the invention to provide a drive for a light source with a corresponding auxiliary device, such as a heater.

The object is achieved by a swinging choke according to claim 1 having a winding body, a core which is inserted in the winding body such that the core forms an air gap in the winding body, at least one main winding which is wound on the winding body and designed for high voltage is, and at least one auxiliary winding whose number of turns is designed so that a low voltage can be tapped and which is arranged along the air gap. Further, the invention provides a drive for a lighting device that uses such a swing throttle.

• einem Wickelkörper, der in mindestens zwei Wickelkammern unterteilt ist;
• einem zweiteiligen Kern, wobei jeder Teilkern einen E-förmigen Querschnitt mit zwei gleichlangen Außenschenkeln einer ersten Länge h1 und einem etwas kürzeren Mittelschenkel einer zweiten Länge h2 aufweist, und wobei der zweiteilige Kern in dem Wickelkörper eingesetzt ist, so dass der zusammengesetzte Doppel-E-Kern einen Luftspalt mit der Dicke d = (h1 - h2) x 2 + a zwischen den Mittelschenkeln der Teilkerne ausbildet, wenn die Stirnflächen von gegenüberliegenden Außenschenkeln einen Abgleichabstand a aufweisen;
• mindestens einer Hauptwicklung, die auf dem Wickelkörper aufgewickelt ist und die durch die mindestens zwei Wickelkammern in eine erste Hauptwicklung und eine zweite Hauptwicklung unterteilt ist, wobei die Hauptwicklung für Hochspannung ausgelegt ist, und
• mindestens eine Hilfswicklung, die über der Hauptwicklung in mindestens einer Wickelkammer entlang dem Luftspalt (10) angeordnet ist, und deren Windungszahl so ausgelegt ist, dass eine niedrige Spannung abgegriffen werden kann.

In detail, according to a preferred embodiment, a swing throttle is provided with the following elements:

• a winding body which is divided into at least two winding chambers;
• a two-part core, wherein each partial core has an E-shaped cross section with two equal length outer legs of a first length h1 and a slightly shorter middle leg of a second length h2, and wherein the two-part core is inserted in the winding body, so that the composite double E Core forms an air gap with the thickness d = (h1-h2) x 2 + a between the middle limbs of the split cores, when the end faces of opposite outer limbs have a matching distance a;
• at least one main winding which is wound on the winding body and which is divided by the at least two winding chambers into a first main winding and a second main winding, wherein the main winding is designed for high voltage, and
• at least one auxiliary winding, which is arranged above the main winding in at least one winding chamber along the air gap (10), and whose number of turns is designed so that a low voltage can be tapped.

By the auxiliary winding, the supply of an auxiliary circuit, for. B. a heater allows. Since there are very high voltages at the main winding and the voltage on the auxiliary winding should be comparatively very low (for example in the range of 5 to 15 volts), very few windings are required for the auxiliary winding (1 to 5 turns). It follows that the few turns of the auxiliary winding have a large positioning latitude in the winding chamber. Since, due to inhomogeneities of the core and stray fields, the inductance of the auxiliary winding depends strongly on the position of the auxiliary winding in the winding chamber, it is difficult to reproduce an auxiliary winding with a defined inductance and thus with a definable voltage that can be tapped.

According to the invention, however, it has been found that the inductance of the auxiliary winding changes parabolic with the distance to the air gap. This means that the position dependency of the inductance is lowest in the vicinity of the air gap. An arrangement of the auxiliary winding as close as possible to or above the air gap therefore solves the problem of large manufacturing tolerances and serial loyalty for a swinging choke with auxiliary winding.

By way of example, the winding body has a dividing wall, whereby the winding body is subdivided into two winding chambers. The partition wall is arranged circumferentially along the air gap, so that the first and the second main winding each enclose a center leg of one of the two E-shaped cores and the partition surrounds the air gap.

A general advantage of dividing the winding body into several winding chambers is that the so-called layer tension can be kept low. If the number of turns for a winding layer is very large, due to the generally high voltage on the main winding and the voltage drop along the winding wire of a layer, the voltage difference between two winding layers is very large, so that the problem arises that a flashover within individual layers due to the large potential difference is possible. By dividing the winding body into a plurality of winding chambers, one can keep the number of turns per layer small and the potential difference between two successive winding layers is correspondingly smaller.

Furthermore, the potential difference between the uppermost layer of the main winding in a winding chamber and the properly arranged auxiliary winding is correspondingly lower, so that the risk of a rollover between the main winding and the auxiliary winding is lower.

In order to achieve a position of the auxiliary winding in the vicinity of the air gap, the auxiliary winding is wound over the main winding in the first half, more preferably in the first third, more preferably in the first quarter and particularly preferably in the first eighth of the winding chamber on the side facing the partition. Since the partition wall is arranged along the air gap, it is also possible to use the partition as a stop for winding the auxiliary winding, so that the auxiliary winding is located close to the air gap. This improves the precision and reproducibility of the inductance in the production.

According to the invention, the winding body has two partitions which subdivide the winding body into three winding chambers. The partitions are arranged so that a middle of the three winding chambers is arranged circumferentially along the air gap. The auxiliary winding is then wound on the main winding in the middle jacking chamber.

The advantage of this arrangement is that the auxiliary winding can be positioned more accurately over the air gap and thereby an even lower positional dependence of the inductance can be achieved.

In an advantageous development of the present invention, two auxiliary windings are arranged symmetrically to the air gap and in the immediate vicinity of the air gap.

Due to the symmetrical arrangement, one obtains almost identical inductances and almost the same inductance drop under load. As a result, a very low production spread is achieved during production, and as exact as possible voltages can be tapped on the auxiliary windings.

In one embodiment, the gauge of the thickness of the air gap is 1.4 mm. This measure is suitable for a choke in a ballast for igniting and operating bulbs.

In a further embodiment, the dividing wall has a thickness of 1.5 mm. Also, this measure proved to be suitable for a swinging choke for use in a ballast for igniting and operating a bulb.

Preferably, this type of oscillating chokes in an electronic ballast for igniting and operating fluorescent tubes, or gas discharge lamps can be used.

In an advantageous development, at least one of the electrodes of the abovementioned light-emitting means is heated via the voltage which is tapped off at the auxiliary winding. This improves the life of the lamp.

In a further aspect of this invention, there is provided a drive for a lighting device which employs a swinging choke as described above.

• Fig. 1 einen Schnitt durch einen Wickelkörper und einen noch nicht eingesetzten zweiteiligen E-förmigen Kern zeigt;
• Fig. 2 ein Induktivitäts-Abstandsdiagramm zeigt;
• Fig. 3 einen Schnitt durch eine Schwingdrossel mit zwei Wickelkammern zeigt; und
• Fig. 4 einen Schnitt durch eine Schwingdrossel mit drei Wickelkammern zeigt.

In the following, various embodiments will be explained with reference to the accompanying drawings, in which:

• Fig. 1 shows a section through a winding body and a not yet inserted two-part E-shaped core;
• Fig. 2 shows an inductance distance diagram;
• Fig. 3 shows a section through a swing throttle with two winding chambers; and
• Fig. 4 shows a section through a swing throttle with three winding chambers.

Fig. 1 shows by way of example a sectional view of a wound body 1, through a partition wall 2 in two Winding chambers 3a and 3b is divided. A two-part core 4a and 4b is shown in the separated state, in which the core 4a, 4b is not yet inserted into the winding body 1. Each sub-core 4a, 4b has an E-shaped cross section, with two equal length outer legs 5a, 5b, 6a and 6b of length h1 and a slightly shorter center leg 7a and 7b of length h2. In this case one speaks of a symmetrical double E-core. However, other cross-sectional shapes are possible. For example, the two-piece core may be realized by two sub-shells having a U-shaped cross-section or a sub-core having a U-shaped cross section and a sub-core having an I-shaped cross section. Also a double-L-core is possible. The split cores can be symmetrical or non-symmetric. The winding body is not limited to winding body with several winding chambers. Depending on the height of the operating voltage and the insulation of the winding wires and wound body with only one winding chamber are possible.

In an implementation of the two-part core with a respective E-shaped cross-sectional area, the outer legs 5a, 5b, 6a and 6b and the middle legs 7a, 7b are of cuboid design. According to this embodiment of the core 4a, 4b, the winding body 1 may also have a cuboidal basic structure.

The winding body 1 is made of a non-metallic and non-conductive material or of a magnetically non-active material, preferably made of a plastic by injection molding. But there are also other materials such as ceramic usable. The core 4a, 4b preferably contains a ferromagnetic material.

To an exemplary swing throttle according to the FIG. 1 To obtain a main winding in a first winding chamber 3a and then applied in at least one second winding chamber 3b. Subsequently, at least one auxiliary winding is wound adjacent to the dividing wall 2. Subsequently, the two parts of the two-part core 4a, 4b are inserted from opposite sides of the winding body 1. In some embodiments, the inductance of the winding during insertion of the two-piece core is measured and the two sub-cores 4a, 4b are so long from inserted opposite ends of the bobbin in the winding body until a predetermined inductance value results. Between the end surfaces 11 of the outer legs 5a, 5b, 6a, 6b remains a so-called adjustment distance a, which can also assume the value zero. The adjustment distance a is optionally filled with magnetically inactive material. For example, gas bubbles may be used as the filling material, optionally with a binder such as silicone. Since the middle limbs 7a and 7b are shorter than the outer limbs 5a, 5b 6a and 6b, an air gap 10 with the thickness d = 2 × (h1-h2) + a is formed between the middle limbs 7a, 7b of the split cores 3a, 3b. In the Fig. 1 the winding body 1 has a single partition wall 2, which is arranged circumferentially along the air gap 10. Since the auxiliary winding was wound adjacent to the dividing wall 2, the auxiliary winding is in the greatest possible proximity to the air gap, whereby a very low production spread of the production can be achieved and the auxiliary windings are arranged symmetrically to the air gap and thus can deliver as accurate as possible same voltage.

The invention already has its effect when the auxiliary winding over the main winding in the first third, preferably a quarter, most preferably one-eighth, the winding chamber on the partition wall (2) facing side is wound.

Fig. 2 shows a diagram in which the inductance L as a function of the distance S in the axial direction with respect to a winding axis A between the air gap 10 and the Hitfswicklung 9 is shown. How out Fig. 2 can be seen, the distance dependence of the inductance L has a parabolic shape with the minimum of the parabola in the center of the air gap. This means that the distance dependence of the inductance L at the air gap 10 is lowest since the slope dL / da at the vertex of the parabola is zero.

Fig. 3 shows a section through an exemplary swing throttle, wherein the winding body 1 is divided into two winding chambers 3a and 3b by a partition wall 2. As a result, the main winding is divided into a first partial main winding 8a and a second partial main winding 8b. How out Fig. 3 it can be seen, two auxiliary windings 9a and 9b are symmetrical to the air gap 10th educated. Characterized in that the partition wall 2 are used as a stop for winding the auxiliary windings 9a, 9b, one achieves an arrangement of the auxiliary windings 9a, 9b close to the air gap 10 and a symmetrical alignment of the auxiliary windings 9a and 9b to the air gap 10. Die FIG. 3 also shows connection pins 12 connected to the winding wires. The connection pins 12 are integrated with the winding body 1 to a base in such a way that the winding axis A are arranged parallel to the connection pins 12. However, the base may also be formed so that the connection pins 12 are arranged perpendicular to the winding direction.

Fig. 4 shows a section through a technical realization of a swing throttle according to the invention, in which the winding body 1 is divided by two partitions 2a and 2b in three winding chambers 3a, 3b and 3c. As a result, the main winding is divided into a first part main winding 8a, a second part main winding 8b and a third part main winding 8c. The second part main winding 8b is arranged in the second (middle) winding chamber 3b and encloses the air gap 10. The auxiliary winding 9a, 9b is centered in the wound up mean winding chamber 3b. How out Fig. 4 can be seen, the auxiliary windings 9 are centered and arranged symmetrically to the air gap 10 and allow a particularly position-independent inductance, whereby manufacturing tolerances and series variations can be minimized. As in FIG. 3 also shows the embodiment in FIG. 4 Terminal pins 12 connected to the winding wires. The connection pins 12 are integrated with the winding body 1 to a base in such a way that the winding axis A are arranged parallel to the connection pins 12. However, the base may also be formed so that the connection pins 12 are arranged perpendicular to the winding direction.

The present invention has been exemplified by way of embodiments. The scope of the invention is not limited to the description, but defined by the claims. For example, embodiments are conceivable with more than two partitions and more than three winding chambers. Likewise, more than one Main winding and more than two auxiliary windings conceivable. Furthermore, round, oval or rectangular leg cross-sections of the core are possible.

Claims (12)

1. Swinging choke with:

   a winding body (1);

   a core (4a, 4b) that is integrated into the winding body (1) such that at least one air gap (10) is formed in the winding body by the core;

   at least one main winding (8a; 8b, 8c); wound onto the winding body (1) wherein the main winding (8a; 8b, 8c) is designed for a high voltage; and

   at least one ancillary winding (9a, 9b) the number of turns of which is designed such that a low voltage can be tapped and which is arranged over or close to the air gap (10),

   wherein the winding body (1) comprises two dividing walls (2a, 2b) which subdivide the winding body (1) into three winding chambers (3a, 3b, 3c),

   characterized

   in that the central winding chamber (3b) is arranged along the air gap (10), and

   in that the ancillary winding (9a, 9b) is arranged in the central winding chamber (3b) along the air gap (10).
2. Swinging choke according to claim 1, wherein the ancillary winding (9a, 9b) is wound over the main winding (8a; 8b) at least partially.
3. Swinging choke according to any one of the previous claims, wherein the winding body (1) is subdivided into at least two winding chambers (3a, 3b),
   wherein the at least one main winding (8a; 8b, 8c) is subdivided by the at least two winding chambers (3a, 3b, 3c) into a first partial main winding (8a) and a second partial main winding (8b), and wherein
   the at least one ancillary winding (9a, 9b) is wound over the main winding (8a; 8b) in at least one winding chamber (3a, 3b, 3c).
4. Swinging choke according to any one of the previous claims, wherein the core comprises at least two partial cores, wherein each partial core of the two-part core (4a, 4b) comprises an E-shaped cross-section with two external legs (5a, 5b, 6a, 6c) of the same length, namely a first length (h1), and a somewhat shorter central leg (7a, 7b) of a second length (h2), and wherein the two-part core (4a, 4b) is integrated into the winding body (1), such that the assembled double-E-core forms the air gap (10) between the central legs (7a, 7b) of the partial cores (4a, 4b), when the front faces (11) have a balance distance (a) from opposite external legs (5a, 5b, 6a, 6c).
5. Swinging choke according to any one of the previous claims, wherein the ancillary winding (9a, 9b) only comprises one to five windings.
6. Swinging choke according to any one of the previous claims, wherein two ancillary windings (9a, 9b) are formed which are arranged so as to be as symmetrical as possible to the air gap (10).
7. Swinging choke according to any one of the previous claims, wherein the thickness of the air gap (10) is 1.4 mm.
8. Swinging choke according to any one of the previous claims, wherein the dividing wall (2) comprises a thickness of 1.5 mm.
9. Swinging choke according to any one of the previous claims, which is designed such that the main winding (8a; 8b, 8c) can be used for driving a lamp, and the voltage tapped by the ancillary winding (9a, 9b) can be used for heating lamp elements.
10. Swinging choke according to claim 9, wherein the lamp is a fluorescent tube or a gas discharge lamp.
11. Swinging choke according to claim 9 or 10, wherein the voltage tapped by the ancillary winding (9a, 9b) can be used for heating at least one electrode of the lamp.
12. Driver for a lamp with a swinging choke according to any one of the claims 1-11.

Images