A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
This application claims benefit of the following patent application(s) which is/are hereby incorporated by reference: None
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The present invention relates generally to magnetic devices that include wire windings around a core. More particularly, this invention pertains to magnetic devices that transfer, balance, distribute or allocate power between different loads in an electric circuit, such as lamp ballast circuits.
Multiple gas discharge lamps may be connected on different circuit paths so that if one lamp burns out, the other lamps can remain lit. In some applications, the lamps require more power to start or ignite. In such a circuit, a lamp that ignites first may clamp the startup voltage, and other lamps connected on different circuit paths may receive insufficient startup voltage and remain unlit. There are other situations where multiple lamps on multiple parallel outputs must receive higher voltages to start or ignite, and the lamp to start first clamps the startup voltage, reducing available power for other loads.
Others have attempted to overcome such problems by providing a separate power source for each load or lamp. However, these conventional solutions add components and cost to the overall circuit application. These conventional solutions also increase the size, power consumption, and heat produced by the overall circuit application. Another solution is placing each lamp on a separate circuit with its own power source, which is also costly and adds components.
What is needed, then, are improvements in magnet devices for lamp ballast circuits.
One aspect of the present disclosure is a magnetic device including first and second magnetic cores mated together, the first and second magnetic cores defining first, second, and middle legs extending between first and second back walls. The first leg, second leg, middle leg, and first and second back walls can have a substantially equal width. At least a first winding is located on the first leg, at least a second winding is located on the second leg, and a third winding is located on the middle leg. In some embodiments, the magnetic device can include a printed circuit board electrically connected to the first, second, and third windings. In some embodiments, the first and second magnetic cores can each have an E-core configuration.
Another aspect of the present disclosure is an electronic ballast circuit including an AC power source, a positive AC rail, and a negative AC rail coupled to the AC power source. A resonant circuit including a resonant capacitor can be coupled between the positive AC rail and the negative AC rail. First, second, third, and fourth positive lamp terminals can be configured to couple to respective gas discharge lamps. First, second, third, and fourth negative lamp terminals can be configured to couple the negative AC rail to respective gas discharge lamps. The electronic ballast circuit can include a magnetic device including first and second magnetic cores each having an E-core configuration. The first and second magnetic cores can be substantially aligned to define first, second, and middle legs extending between first and second back walls. The first leg, second leg, middle leg, and first and second back walls can have a substantially equal width. A first winding can be located on the first leg and coupled between the positive AC rail and the first positive lamp terminal. A second winding can be located on the second leg and coupled between the positive AC rail and the second positive terminal. A third winding can be located on the middle leg, the third winding coupled between the AC power source and the positive AC rail, the third winding configured to define a resonant inductor in the resonant circuit. A fourth winding can be located on the first leg and coupled between the positive AC rail and the third positive lamp terminal. A fifth winding can be located on the second leg and coupled between the positive AC rail and the fourth positive lamp terminal.
One object of the present invention is to provide a device that can transfer, balance, allocate, or distribute power between one or more loads on an electric circuit.
Another object of the invention is to provide a device capable of transferring, balancing, allocating, or distributing power between different paths of an electric circuit.
Another object of the invention is to provide a common mode choke and a differential mode choke configured on the same magnetic core.
Another object of the invention is to provide a magnetic device that can act as a starting aid for multiple gas discharge lamps on different paths of an electric circuit.
Yet another objective of the invention is to provide a magnetic device that includes a resonant inductor as well as multiple starting aid windings on the same core.
Numerous other objects, advantages and features of the present invention will be readily apparent to those of skill in the art upon a review of the following drawings and description of a preferred embodiment.
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that is embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.
To facilitate the understanding of the embodiments described herein, a number of terms are defined below. The terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as “a,” “an,” and “the” are not intended to refer to only a singular entity, but rather include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as set forth in the claims. Numerical terms such as first, second, third, etc. as used herein are meant to help identify different aspects of the embodiments, but their usage does not delimit the scope of the invention, except as set forth in the claims.
As described herein, an upright position is considered to be the position of apparatus components while in proper operation or in a natural resting position as described herein. Vertical, horizontal, above, below, side, top, bottom and other orientation terms are described with respect to this upright position during operation unless otherwise specified. The term “when” is used to specify orientation for relative positions of components, not as a temporal limitation of the claims or apparatus described and claimed herein unless otherwise specified.
The present invention provides a magnetic device that can be used in an electric circuit, the magnetic device having a core with multiple windings that can be configured to transfer, balance, allocate, or distribute power across multiple paths of a circuit in order to power multiple loads.
A first embodiment of a magnetic device 10 is shown in
An embodiment of an electronic ballast circuit 80 that may utilize the magnetic device 10 of
AC power source 32 and an equivalent voltage produced by the resonant circuit can provide an electric current which flows to first lamp 34 and second lamp 36. First and second lamps 34 and 36 can be connected on different electrical paths such that in the event one lamp fails, the other lamp is unaffected on another current pathway, and therefore can remain lit. During startup, an excess amount of power may be supplied by the resonant circuit to ignite lamps 34 and 36. Either first lamp 34 or second lamp 36 may ignite first. The lamp that ignites first can clamp the startup voltage as it ignites, leaving insufficient startup voltage for the other lamp. For instance, assuming first lamp 34 lights first, the startup power supplied by AC power source 32 and the resonant circuit could be clamped by first lamp 34. As such, second lamp 36 may not light.
To address this problem, magnetic device 10 can be implemented in a circuit to facilitate startup of all lamps. First winding 20 on first leg 14 can be connected in series with first lamp 34. Second winding 22 on second leg 16 can be connected in series with second lamp 36. As current from the resonant circuit flows to first lamp 34, it passes through first winding 20. The current through first winding 20 induces a magnetic flux in magnetic core 12. The magnetic flux passes through core 12, and subsequently through second winding 22. The changing magnetic flux through second winding 22 induces an electric current in second winding 22, which can assists in powering second lamp 36. A similar process can be seen when second lamp 36 lights first. As such, first and second windings 20 and 22 can act as startup aids for first and second lamps 34 and 36 respectively. Additionally, as shown in
Additionally, third winding 24 on middle leg 18 can be a resonant inductor for the resonant circuit of the electronic ballast circuit 80. Thus, the magnetic device 10 can have a resonant inductor 24 as well as multiple startup aid windings 20 and 22 on the same magnetic core 12. This is a significant benefit of magnetic device 10 as conventionally the resonant inductor function and the starting aid function were performed using two different magnetic components. As such, magnetic device 10 can help minimize the overall size and cost of an electronic ballast circuit and related magnetic component.
A top view of one embodiment of core 12 used in magnetic device 10 can be seen in
Additionally, in some embodiments, each of magnetic cores 12a and 12b can have an E-core configuration. First back wall 40 can be located on first E-core 12a, and second back wall 42 can be located on second E-core 12b. The two E-cores 12a and 12b can be substantially aligned to form core 12. As such, the first, second, and third windings 20, 22, and 24 located on the assembled core 12 can be pre-wound on first, second, and third bobbins 26, 28, and 30, shown in
Examples of magnetic flux paths which can be produced in magnetic device 10 of
A first flux path 52 extends through first and second legs 14 and 16 of core 12, and passes through first and second windings 20 and 22. Therefore, the first and second windings 20 and 22 are positioned on core 12 such that they are magnetically coupled via first flux path 52. When current passes through one winding, magnetic flux is produced which can flow along first flux path 52 and induce a current in the other winding.
A second flux path 54 can pass in first leg 14 and middle leg 18 and through first winding 20 and third winding 24. As such, first winding 20 and third winding 24 can be positioned on core 12 such that they are magnetically coupled together via second flux path 54.
A third flux path 56 may pass in middle leg 18 and second leg 16, and through second winding 22 and third winding 24. As such, second winding 22 and third winding 24 can be positioned on core 12 such that they are magnetically coupled together via third flux path 56.
Additionally, in some embodiments, the windings on magnetic device 10 shown in
A second embodiment of magnetic device 10 is shown in
Furthermore, the second embodiment of magnetic device 10 can include a fourth bobbin 62 and a fifth bobbin 64 located on core 12. Fourth winding 58 and fifth winding 60 can be located on fourth bobbin 62 and fifth bobbin 64 respectively. Fourth bobbin and fifth bobbin 62 and 64 can help contain fourth and fifth windings 58 and 60 to their respective locations on core 12.
An embodiment of an electronic ballast circuit 80 which can utilize the magnetic device of
With the magnetic device connected to the circuit, and the windings connected in series with the lamps, as a first lamp is ignited, current passes through the winding associated with that lamp, either the first, second, fourth, or fifth windings 20, 22, 58, or 60. A magnetic flux is created in core 12 which extends along first flux path 52 and passes through the remaining windings. The changing magnetic flux in first flux path 52 can induce current in each of the other three windings, and the currents induced in the other three windings can assist in lighting the corresponding lamps. As such, the first, second, fourth, and fifth windings 20, 22, 58, and 60 can be configured to act as startup aids for corresponding lamps when current passes through any one of the windings. Again, the polarities of the windings, represent by numerals 1 and 2, are reversed for each coupled pair of windings in the circuit.
In the circuit 80 shown in
A perspective exploded view of an embodiment of the magnetic device 10 of
Additionally, as shown in
A third embodiment of magnetic device 10 is shown in
The flux paths that can be produce in the embodiment of
A perspective exploded view of magnetic device 10 of
The magnetic device of
Printed circuit board 76 in
The printed circuit board can define a variety of electrical circuits, including circuits similar to electronic ballast circuits 80 shown in
Thus, although there have been described particular embodiments of the present invention of a new and useful Multifunction Magnetic Device with Multiple Cores and Coils it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.
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