Abstract:
An electrical reactor assembly and method of assembly is disclosed. The reactor is formed from a combination of a magnetic T-core and a pair of magnetic L-cores. A plurality of comb-like separators is placed over a vertical portion of the T-core. A wire, with a rectangular cross-section, is wound about the vertical portion of the T-core thereby forming a coil. The comb-like separators electrically isolate the wire from adjacent windings and the T-core. The L-cores are attached to the T-core such that they flank two sides of the coil. A plurality of taps is formed on a side of the coil that is not flanked by one of the L-cores. The taps are formed by extending individual windings further from the T-core than other common windings. Preferably, a hole is formed through the rectangular wire at the taps to provide a secure electrical connection to the wire.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present invention is a continuation and claims the benefit and priority of U.S. Ser. No. 10/249,339, the disclosure of which is incorporated herein. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates generally to welding-type devices and, more particularly, to an electrical reactor assembly having a plurality of electrical taps formed in the windings of the reactor.  
         [0003]     Reactor assemblies are commonly used in welding-type devices to condition and control a power signal so that it may be used in supplying power such as in a welding process. For example, reactor assemblies are often implemented in the electrical circuitry of a welding-type device to control the current provided to the work-piece and supplied by a boost converter assembly. Boost converters are frequently used so that the welding-type device may be operated on a variable voltage source. That is, the boost converter enables the welding-type device to be operable with voltages ranging typically from 115 volts to 230 volts. Typically, the signal is input to a rectifier that in turn outputs the rectified power signal to the boost converter for conditioning whereupon the boost converter outputs a conditioned signal to the inverter of the welding-type device and creates AC power for transformers of the welding-type device.  
         [0004]     Additionally, internal combustion engines have often been incorporated into welding-type devices so that the entire device is portable. Welding-type devices that include internal combustion engines as a power supply, generate an electrical signal such that the devices can power both a welding-type device as well as multiple electrical outlets. These devices generally include a generator to supply power for accessories. The combination of the engine to the welding-type device makes the welding device portable and also provides a remote source of power for tools such as grinders, drills, and saws.  
         [0005]     Regardless of the source of the power supply, i.e. a wall plug or a portable engine, the electrical signal preferably needs to be conditioned and controlled by passage through a reactor. Typically, the reactor includes of a ferrite core and several turns of magnetic wire. The magnetic wire is generally isolated from the ferrite core through the use of foil insulation around the core or by insulating the wire itself. The reactor needs to electrically insulate individual windings from both adjacent windings and from the ferrite core. The insulation requirement often creates a reactor assembly with a generally closed construction. The closed construction of the reactor assembly inhibits cooling of the reactor. Reactors generally generate a considerable amount of heat due to the relatively high voltages and currents that pass therethrough. The generation of heat signifies electrical losses within the welding device. The closed construction of reactors inhibits cooling of the reactor which in turn increases the inefficiencies of the reactor which in turn reduce the overall efficiency of the welding-type device. The heat generation of the reactor is also detrimental to the reactor itself and can effectively shorten the operating life of the reactor. Additionally, the thermal losses that exist, are generated along the entire length of the wire of the reactor that is utilized to condition and control the electric signal passed through the reactor. These thermal inefficiencies result in increased operating expenses whether from increased fuel consumption by the engine or electrical power consumption.  
         [0006]     It would therefore be desirable to design a reactor with multiple taps to limit the length of the reactor that is unnecessarily powered. It is also desirable to design a reactor that is sufficiently cooled during operation to reduce thermal inefficiencies of the welding-type device and prevent premature failure of the reactor. It would also be desirable to design the reactor that is easily and inexpensively assembled.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0007]     The present invention is directed to a reactor for a welder-type device. Preferably the reactor includes a plurality of comb-like structures that provide electrical isolation of a wire wound onto a coil about a T-core. The coil includes a plurality of common windings and a plurality of tap windings. The comb-like structures also provide electrical isolation between adjacent windings. The tap windings extend past the common windings along a common side of the T-core. Additionally, a pair of L-cores is attached to the T-core such that the L-cores flank opposing sides of the coil. All of which overcome the aforementioned drawbacks.  
         [0008]     Therefore in accordance with a first aspect of the present invention, an electrical reactor is disclosed. The electrical reactor has a magnetic core. A wire is wound concentric to the magnetic core to form a coil. A plurality of taps is formed integrally in the wound wire by extending a plurality of individual windings beyond adjacent windings.  
         [0009]     In accordance with another aspect of the present invention, an apparatus to provide multiple voltages to a welder-type device is disclosed. The apparatus includes a magnetic T-core and a pair of magnetic L-cores. A wire is wound about the T-core multiple times thereby forming a plurality of windings which thereby form a coil. A selected number of the windings are wound with a larger air gap than the air gap formed by a majority of the windings.  
         [0010]     In accordance with yet another aspect of the present invention, a reactor includes a T-core with a wire wound about a vertical portion of the T-core to form a coil. The coil has a plurality of common windings and a plurality of tap windings. A pair of L-cores is attached to the T-core and thereby forms a first and a second window. The tap windings are formed by passing a winding from the first window to the second window and extending the tap winding farther from the vertical portion of the T-core than the common windings.  
         [0011]     In accordance with yet another aspect of the present invention, a method of assembling a reactor is disclosed. The method comprises the steps of positioning a comb-like separator adjacent a T-core, winding a wire snuggly about the comb-like separator to form a common winding profile about the T-core, forming a plurality of tap windings by leaving a substantial gap between the tap winding and adjacent windings at a predetermined number of turns, and attaching a pair of L-cores to the T-core.  
         [0012]     Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention.  
         [0014]     In the drawings:  
         [0015]      FIG. 1  is a perspective view of the welding device according to the present invention.  
         [0016]      FIG. 2  is a perspective view of an electrical reactor assembly used in the welding device shown in  FIG. 1 .  
         [0017]      FIG. 3  is a side elevational view of the electrical reactor assembly shown in  FIG. 2 .  
         [0018]      FIG. 4  is a cross-sectional exploded side elevation view of the electrical reactor assembly shown in  FIG. 2 .  
         [0019]      FIG. 5  is a cross-sectional top view at line  5 - 5  of the electrical reactor assembly shown in  FIG. 4   
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]     As one skilled in the art will fully appreciate, the hereinafter description of welding devices not only includes welders, but also includes any system that requires high power outputs, such as heating and cutting systems. Therefore, the present invention is equivalently applicable with any device requiring high power output, including welders, plasma cutters, induction heaters, and the like. Reference to welding power, welding-type power, welding device, welder-type device, welder device, or welders generally, includes welding, cutting, or heating power. Description of a welding apparatus illustrates just one embodiment in which the present invention may be implemented. The present invention is equivalently applicable with any power system requiring multiple.  
         [0021]      FIG. 1  shows a welding device  10 . Welding device  10  includes a housing  12  which encloses the internal components of the welding device including, a reactor assembly as will be described in greater detail below. Optionally, welding device  10  includes a loading eye  14  and/or fork recesses  16 . Loading eye  14  and fork recesses  16  facilitate the portability of welding device  10 . Optionally, the welding device could include a handle and/or wheels as a means of device mobility. Housing  12  also includes a plurality of access panels  18 ,  20 . Access panel  18  provides access to a top panel  22  of housing  12  while access panel  20  provides access to a side panel  24  of housing  12 . A similar access panel is available on an opposite side. An end panel  26  includes a louvered opening  28  to allow for air flow through housing  12 .  
         [0022]     Housing  12  of welding-type device  10  also houses an internal combustion engine. The engine is evidenced by an exhaust  30  and a fuel port  32  that protrude through housing  12 . Exhaust  30  extends above top panel  22  of housing  12  and directs exhaust emissions away from the welding-type device  10 . Fuel port  32  preferably does not extend beyond top panel  22  or side panel  24 . Such a construction protects fuel port  32  from damage during transportation and operation of welding-type device  10 . Although shown to include an engine, the present invention is equally applicable to welding-type devices that require an external power source.  
         [0023]     Housing  12  protects the internal combustion engine and the internal components of welding-type device  10  or internal generator components. One such component is a reactor assembly  34  as shown in  FIG. 2 . Reactor assembly  34  includes a T-core  36  and a pair of L-cores  38 . T-core  36  and L-cores  38  are preferably formed of a ferrite material with desirable magnetic attributes. A wire  40  is wound from a first end  42  to a second end  44  about a vertical portion  46  of T-core  36  to form a coil  48 . First end  42  and second end  44  of coil  48  each include a wire hole  50 . Wire holes  50  provide electrical supply connections to wire  40  of coil  48 . Coil  48  includes a plurality of common windings  52  and a plurality of tap windings  54  formed between first end  42  and a second end  44  of coil  48 . Tap windings  54  provide electrical access to coil  48  at different potentials by extending further from T-core  36  than common windings  52 . Preferably, wire holes  50  provide electrical access to coil  48  at tap windings  54 . Assuming coil  48  is energized from first end  42  through one of the tap windings  54 , that portion of the coil  48  outside of this circuit would not be energized and therefore would not generate thermal losses. That is, no more of the reactor needs to be powered than is necessary for the desired device output. This ability thereby reduces overall losses when compared to a reactor without tap windings.  
         [0024]      FIG. 3  shows a side view of the reactor assembly  34  of  FIG. 2 . Common windings  52  and tap windings  54  are separated by a distance  56 . Distance  56  is determined by a fin of comb-like separator, as will be addressed in reference to  FIG. 4  below. Distance  56  is uniform throughout coil  48 . Additionally, common windings  52  extend a distance  62  from a side surface  64  of L-core  38 . Tap windings  54  extend a distance  66  from side surface  64  of L-core  38  that is farther than common winding distance  52 . In one embodiment, first end  42  and second end  44  of wire  40  of coil  48  extend a distance  68  from side surface  64  of L-core  38  that is still further than tap winding distance  66 . As such, first end  42  and second end  44  extend further from L-core  38  than tap windings  54  which in turn extend further from L-core  38  than common windings  52 . Additionally, coil  48  does not extend into an upper portion  70  and a lower portion  72  of reactor assembly  34 .  
         [0025]      FIG. 4  shows upper portion  70  and lower portion  72  of reactor assembly  34  in a broken and partially exploded view. The upper and lower portions  70 ,  72  connect a plurality of horizontal portions  74  of L-cores  38  and a horizontal portion  76  of T-core  36 . Horizontal portions  74  of L-cores  38  are attached to vertical portion  46  of T-core  36  at lower portion  72  of reactor assembly  34 . A vertical portion  78  of L-cores  38  is attached to horizontal portion  76  of T-core  36  at upper portion  70  of reactor assembly  34 . This construction, when assembled, forms a first window  80  and a second window  82  through reactor assembly  34 . Positioned in first window  80  and second window  82 , along vertical portion  46  of T-core  36 , are comb-like separators  60 . These comb-like separators  60  each have a longitudinal base  84  adjacent vertical portion  46  of T-core  36 . Extending from longitudinal base  84  of comb-like separators  60  are a plurality of fins  86 . The thickness of fins  86  determines distance  56  between adjacent windings as discussed with respect to  FIG. 3  and is generally selected to snuggly retain the windings therein. Referring back to  FIG. 4 , wire  40  is snuggly disposed between adjacent fins  86  of comb-like separator  60 . Comb-like separator  60  provides electrical isolation of wire  40  from adjacent windings and from T-core  36 . Additionally, comb-like separator  60  extends past wire  40  toward L-cores  38  to provide the necessary gap between wire  40  and the L-cores  38  of coil  48 .  
         [0026]     As shown in  FIG. 4 , wire  40  has a rectangular cross section  88  that forms a pair of short sides  90  and a pair of long sides  92 . One of short sides  90  of wire  40  is wound adjacent separator base  84  of comb-like separator  60 . Long sides  92  of wire  40  are parallel to fins  86  of comb-like separator  60 . In effect, wire  40  is edge wound about vertical portion  46  of T-core  36 . An end portion  93  of fins  86  of comb-like separator  60  is not in direct contact with wire  40 . End portion  93 , not only provides the aforementioned gap, but also further protects wire  40  and provides improved cooling of wire  40  by functioning similar to a fin of a heat sink. In effect, end portion  93  dissipates heat from wire  40  to the atmosphere.  
         [0027]      FIG. 5  is a top view of the reactor assembly  34  of  FIG. 4  broken at line  5 - 5 . Common windings  52  and tap windings  54  of coil  48  surround vertical portion  46  of T-core  36 . Comb-like separators  60  maintain a gap  94  between the coil  48  and vertical portion  46  of T-core  36 . Gap  94  is determined by the thickness of separator base  84  of comb-like separator  60 . Base  84  of comb-like separator  60  also has an L-shaped cross-section  95 . L-shaped cross-section  95  of base  84  of comb-like separator  60  positions comb-like separator  60  on a corner  97  of vertical portion  46  of T-core  36 . Although  FIG. 5  shows four independent separators  60 , it is within the scope of the present disclosure and claims that the number of separators can vary so long as isolation is maintained between adjacent coil windings and the magnetic core.  
         [0028]     An air space  96  is defined generally by the space enclosed by common winding  52  and a side  98  of vertical portion  46  of T-core  36 . A second air gap  100  is defined as a space generally enclosed by tap winding  54  and side  98  of vertical portion  46  of T-core  36 . Tap windings  54  extend further from side  98  of vertical portion  46  of T-core  36  than common windings  52 . Additionally, tap windings  54  include wire holes  50  for improved electrical connectivity to the reactor assembly  34  at tap windings  54 . The structure of reactor assembly  34  provides access to multiple predetermined electrical parameters of coil  48  while also providing a structure that limits thermal losses of the reactor assembly  34  of the welding device  10 .  
         [0029]     Therefore in accordance with an embodiment of the present invention, a magnetic core of an electrical reactor is provided. A wire is wound concentric to the magnetic core to form a coil. A plurality of taps is formed integrally in the wound wire by extending a plurality of individual windings beyond adjacent windings.  
         [0030]     In accordance with another embodiment of the present invention, an apparatus to provide multiple voltages to a welder-type device is provided. The apparatus includes a magnetic T-core and a pair of magnetic L-cores. A wire is wound about the T-core multiple times thereby forming a plurality of windings which thereby form a coil. A selected number of the windings are wound with a larger air gap than the air gap formed by a majority of the windings thereby forming electrical taps in the coil of the reactor assembly.  
         [0031]     The present invention includes a reactor with a T-core and a wire wound about a vertical portion of the T-core to form a coil. The coil has a plurality of common windings and plurality of tap windings. A pair of L-cores is attached to the T-core and thereby forms a first and a second window. The tap windings are formed by passing a winding from the first window to the second window and extending the winding further from the vertical portion of the T-core than the common windings.  
         [0032]     The present invention also includes a method of assembling a reactor. The method includes the steps of positioning a comb-like separator adjacent a T-core, winding a wire snuggly about the comb-like separator to form a common winding profile about the T-core, forming a plurality of tap windings by leaving a substantial gap between the tap winding and adjacent windings at a predetermined number of turns, and attaching a pair of L-cores to the T-core.  
         [0033]     The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.