Patent Publication Number: US-2023141926-A1

Title: Transformer

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 110141320, filed on Nov. 5, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Technical Field 
     The disclosure relates to a transformer, and in particular to a transformer for use in an electronic appliance. 
     Description of Related Art 
     Regarding an existing transformer used in a high-wattage electronic appliance, in order to reduce the size and increase the power density, a high-frequency design is usually used for switching frequency, so that a magnetic component with a smaller effective core area may be used in the transformer to reduce the volume of the transformer. An existing high-frequency transformer is an LLC architecture that combines winding and copper sheets. However, the copper sheets of the existing high-frequency transformer are stacked on the upper and lower sides of the winding, so that air gaps exist between the copper sheets and the winding. When the transformer is energized and operated, the air gaps generate magnetic flux leakage and form a magnetic field, thus causing the loss of eddy current. 
     SUMMARY 
     The disclosure provides a transformer, which avoids the situation of air gaps being generated between winding and a copper sheet so as to reduce magnetic leakage and eddy current loss. 
     A transformer of the disclosure includes a winding frame, a first coil, a second coil, a locating piece, and two iron core pieces. The winding frame has a winding portion, a first baffle, a second baffle, and a terminal socket. The winding portion has a through hole. The first baffle and the second baffle are respectively and horizontally extended from two opposite ends of the winding portion. The terminal socket is connected to the second baffle. The first coil is wound on the winding portion and is electrically coupled to the terminal socket. The second coil is disposed around the outside of the first coil and the first coil and the second coil are spaced apart from each other. The second coil has a plurality of copper sheets, located between the first baffle and the second baffle. The locating piece is correspondingly disposed on the winding frame and is used to locate the second coil. The two iron core pieces are respectively disposed on the second baffle of the winding frame and the locating piece, and the two iron core pieces are disposed so as to pass through the through hole of the winding portion. 
     Based on the above, in the transformer of the disclosure, the first coil is wound on the winding portion, and the second coil is disposed around the outside of the first coil. Therefore, the second coil is wrapped around the periphery of the first coil while the above two are spaced apart from each other instead of being stacked on each other, so that no air gap exists between the second coil and the first coil. Thus, the magnetic leakage phenomenon generated by the transformer after the transformer is energized and operated is avoided, and the loss of eddy current is reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1 A  is a perspective schematic view of a transformer according to an embodiment of the disclosure. 
         FIG.  1 B  is an exploded schematic view of components of the transformer of  FIG.  1 A . 
         FIG.  1 C  is a perspective schematic view of a locating piece of the transformer of FIG.  1 A being engaged with a second coil. 
         FIG.  1 D  is a perspective schematic view of the second coil of the transformer in  FIG.  1 A  being wrapped around a winding frame. 
         FIG.  1 E  is a perspective schematic view of an insulating layer of the transformer in  FIG.  1 A  being wrapped around the winding frame. 
         FIG.  1 F  is a perspective schematic view of the second coil of the transformer of  FIG.  1 A . 
         FIG.  2 A  is a perspective view of the second coil according to another embodiment of the disclosure. 
         FIG.  2 B  is a perspective view of the second coil according to another embodiment of the disclosure. 
         FIG.  2 C  is a perspective view of the second coil according to another embodiment of the disclosure. 
         FIG.  3 A  is a perspective view of the second coil according to another embodiment of the disclosure combined with a cylindrical housing. 
         FIG.  3 B  is a perspective schematic view of the second coil of  FIG.  3 A  disposed around the winding frame. 
         FIG.  4    is a perspective schematic view of the second coil according to another embodiment of the disclosure combined with the cylindrical housing. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Referring to  FIGS.  1 A and  1 B , a transformer  100  of the disclosure includes a winding frame  110 , a first coil  120 , a second coil  130 , a locating piece  140 , and two iron core pieces  150 . 
     The winding frame  110  has a winding portion  111 , a first baffle  112 , a second baffle  113 , and a terminal socket  114 , and the winding frame  110  is made of an insulating material. The winding portion  111  has a through hole TH and has a hollow tube structure, and the through hole TH penetrates the winding portion  111 . The first baffle  112  and the second baffle  113  are respectively and horizontally extended from two opposite ends E of the winding portion  111 . The terminal socket  114  is connected to the second baffle  113  and has a plurality of electrical terminals  1141 . The electrical terminals  1141  extend from the outer edge of the terminal socket  114  toward the direction away from the winding frame  110 , and the electrical terminals  1141  are bent at 90 degrees relative to the terminal socket  114  to form an L-shaped appearance. 
     The first coil  120  is wound on the winding portion  111  of the winding frame  110  and is electrically coupled to the electrical terminals  1141  of the terminal socket  114 . The second coil  130  is disposed around the outside of the first coil  120  and the above two are spaced apart from each other; that is, the second coil  130  is wrapped around the periphery of the first coil  120  and the two does not contact each other. The second coil  130  has a plurality of copper sheets  131  located between the first baffle  112  and the second baffle  113 . The locating piece  140  is correspondingly disposed on the winding frame  110 , and is used to locate the copper sheets  131  of the second coil  130 . The two iron core pieces  150  are respectively disposed on the second baffle  113  of the winding frame  110  and the locating piece  140 , and the two iron core pieces  150  are disposed so as to pass through the through hole TH of the winding portion  111  and are electrically coupled to each other. 
     Referring to  FIGS.  1 C to  1 E , the transformer  100  further includes an insulating layer  160 , wrapped around the outside of the first coil  120  and blocks the second coil  130 , so that the first coil  120  is insulated from the second coil  130 . In other words, the insulating layer  160  is located between the first coil  120  and the second coil  130  to prevent the first coil  120  and the second coil  130  from contacting and conducting each other. 
     Referring to  FIGS.  1 B,  1 D to  1 F , in this embodiment, a first area A 1  of the first baffle  112  is smaller than a second area A 2  of the second baffle  113 . An opening H 1  of the second coil  130  is adapted to pass through the first baffle  112  and the second coil  130  abuts against the second baffle  113 , so that the second coil  130  is wrapped around the winding frame  110  and completely covers the first coil  120 , and the second coil  130  and the first coil  120  overlap each other in a radial direction RD of the winding frame  110 . Based on the assembly method of the first coil  120  (a primary side coil) and the second coil  130  (a secondary side coil) used in this embodiment overlapping in the radial direction RD, no air gap exists between the second coil  130  and the first coil  120 , so the magnetic leakage phenomenon may be reduced. 
     Referring to  FIG.  1 F , each copper sheet  131  of the second coil  130  has an annular main-body  1311  and a plurality of pins  1312 . The pins  1312  extend outward from the annular main-body  1311 , and the pins  1312  are parallel to each other. In this embodiment, the pins  1312  have a linear appearance and are perpendicular to an axial direction AD of the winding frame  110 . The second coil  130  is stacked along the axial direction AD passing through the winding portion  111 , and the pins  1312  jointly form two locating slots PG. 
     Referring to  FIGS.  1 A and  1     i , the winding frame  110  has two first locating portions  115 , respectively disposed on the second baffle  113  and the terminal socket  114 , and the two first locating portions  115  are engaged with the corresponding one of the iron core pieces  150  to avoid shaking or separation of the winding frame  110  and the corresponding iron core piece  150 . 
     Referring to  FIGS.  1 A and  1 B , the locating piece  140  has a ring plate  141 , two locating mounts  142 , two second locating portions  143 , and a blocking plate  144 . The ring plate  141  has an opening H 2 , aligned with the through hole TH of the winding portion  111 . The two locating mounts  142  are disposed on the outer edge of the ring plate  141  and extend toward the second baffle  113 , and the two second locating portions  143  are disposed on an upper surface TS of the ring plate  141 . The blocking plate  144  is disposed on the outer edge of the ring plate  141  and is opposite to the two locating mounts  142 . 
     Referring to  FIG.  1 C , the two locating mounts  142  are disposed around the two locating slots PG of the second coil  130 , and the two locating mounts  142  are used to limit the pins  1312  of the copper sheets  131 , so as to avoid the situation of the copper sheets  131  being separated from each other and the pins  1312  being misaligned. The two second locating portions  143  are engaged with the corresponding iron core piece  150 . The blocking plate  144  partially encapsulates the second coil  130 . Specifically, through the limiting effect of the blocking plate  144  and the two second locating portions  143 , the annular main-bodies  1311  of the copper sheets  131  may be limited on the second baffle  113 . 
     Referring to  FIGS.  1 A and  1     i , each of the iron core pieces  150  has a case  151  and a column  152 . The column  152  is disposed in the case  151 , and the column  152  of one iron core piece  150  is disposed so as to pass through the locating piece  140  and enters the through hole TH of the winding frame  110 . The column  152  of another iron core piece  150  is disposed so as to pass through the second baffle  113  and enters the through hole TH of the winding frame  110 . In this embodiment, the number of iron core pieces  150  is two. The two cases  151  of the two iron core pieces  150  are electrically coupled to each other and are wrapped around the outside of the second coil  130 , and the two case  151  are misaligned with the two second locating portions  143  and the blocking plate  144  of the locating piece  140 . The two columns  152  of the two iron core pieces  150  are electrically coupled to each other in the through hole TH, and the two iron core pieces  150  form a loop. 
     Referring to  FIGS.  1 A and  1 B , a circuit board  170  is further included. The circuit board  170  is disposed on the corresponding iron core piece  150  and is electrically coupled to the electrical terminals  1141  of the terminal socket  114 . 
       FIG.  2 A  is a perspective view of the second coil according to another embodiment of the disclosure. 
     Referring to  FIG.  2 A , in this embodiment, a plurality of copper sheets of a second coil  130   a  include at least one first copper sheet  131   a  and at least one second copper sheet  132   a . A first pin length L 1  of the at least one first copper sheet  131   a  is different from a second pin length L 2  of the at least one second copper sheet  132   a . In this embodiment, the first pin length L 1  is greater than the second pin length L 2 , and in other embodiments, the first pin length L 1  is smaller than the second pin length L 2 . 
     Specifically, the second coil of this embodiment has different pin lengths, adapted for electronic appliances of different specifications. 
       FIG.  2 B  is a perspective view of the second coil according to another embodiment of the disclosure. 
     Referring to  FIG.  2 B , in this embodiment, each copper sheet  131   b  of the second coil has an annular main-body  1311   b  and a plurality of pins  1312   b , and the pins  1312   b  extend from the annular main-body  1311   b  and has a bent appearance. 
     Specifically, the second coil of this embodiment has pins with a bent appearance, adapted for electronic appliances of different specifications. 
       FIG.  2 C  is a perspective view of the second coil according to another embodiment of the disclosure. 
     Referring to  FIG.  2 C , in this embodiment, each copper sheet  131   e  has an annular main-body  1311   e  and two pins  1312   e , and the two pins  1312   e  are respectively formed on two ends of the annular main-body  1311   e , and the two pins  1312   e  are spaced apart from each other. 
       FIG.  3 A  is a perspective view of the second coil according to another embodiment of the disclosure combined with a cylindrical housing.  FIG.  3 B  is a perspective schematic view of the second coil of  FIG.  3 A  disposed around the winding frame. 
     Referring to  FIGS.  3 A and  3 B , a cylindrical housing  180   c  is further included, and a second coil  130   c  is disposed in the cylindrical housing  180   c . Specifically, a plurality of copper sheets  131   c  of the second coil  130   c  are stacked on each other in the cylindrical housing  180   c , and the copper sheets  131   c  are disposed around a winding frame  110   c  and are located between a first baffle  112   c  and a second baffle  113   c . A plurality of pins  1312   c  of the copper sheets  131   c  protrude from the cylindrical housing  180   c . The cylindrical housing  180   c  is made of an insulating material, so that the magnetic field generated by the second coil  130   c  is concentrated in the cylindrical housing  180   c , thereby further reducing the magnetic leakage phenomenon. 
       FIG.  4    is a perspective schematic view of the second coil according to another embodiment of the disclosure combined with the cylindrical housing. 
     Referring to  FIG.  4   , a plurality of cylindrical housings  180   d  are included, and a plurality of copper sheets  131   d  of a second coil  130   d  are respectively disposed in the corresponding cylindrical housings  180   d . Specifically, the copper sheets  131   d  of the second coil  130   d  are respectively stacked on each other in the cylindrical housings  180   d , and the copper sheets  131   d  are disposed so as to pass through a winding frame  110   d  and are located between a first baffle  112   d  and a second baffle  113   d , and the cylindrical housings  180   d  are spaced apart from each other. A plurality of pins  1312   d  of the copper sheets  131   d  respectively protrude from the corresponding cylindrical housing  180   d . The cylindrical housing  180   d  is made of an insulating material, so that the magnetic field generated by the second coil  130   d  is concentrated in the cylindrical housing  180   d , thereby further reducing the magnetic leakage phenomenon. 
     In summary, in the transformer of the disclosure, the first coil is wound on the winding portion, and the second coil is disposed around the outside of the first coil. Therefore, the second coil is wrapped around the periphery of the first coil while the above two are spaced apart from each other instead of being stacked on each other, so that no air gap exists between the second coil and the first coil. Thus, the magnetic leakage phenomenon generated by the transformer after the transformer is energized and operated may be avoided, and the loss of eddy current may be reduced. 
     Furthermore, in the transformer of the disclosure, the first coil (the primary side coil) thereof may be electrically connected to the circuit board through a plurality of electrical terminals of the terminal socket, and this connection method replaces the existing flying lead connection method; and the second coil (the secondary side coil) thereof has a plurality of copper sheets stacked on each other and is wrapped around the outside the first coil. Compared with the current transformer, the transformer of the disclosure has the technical effect of reducing power consumption and lowering operating temperature.