Patent Publication Number: US-6699052-B1

Title: Dual voltage power converter

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a dual voltage power converter, and more particularly, to a bi-voltage power converter including a combination of an adapter and a transformer unit that can be used in different countries around the world. 
     2. Description of the Related Art 
     People rely heavily on a wide variety of electrical devices. Almost all of these devices draw power ultimately from a national standard source, usually delivered to a user through a wall outlet or socket. This leads to a challenge for a manufacturer of electrical devices destined for international use; for instance, while many electrical devices are sold for use throughout the world, there is no world standard for electrical plug configurations. Further, it is well known to travelers that electrical voltage supply in the major countries of the world, not only varies in strength of the voltage offered to the user but in a geometry of a socket at a voltage outlet. It has been common for many years for experienced travelers to equip themselves with an electrical adapter having a multiplicity of pins that can be quickly changed to meet various geometries of the voltage outlets. But to meet the various changes in voltage, a separate voltage converter has also been essential. 
     By the term power or voltage converter is herein meant any device for changing the electrical energy from one strength to another such as a transformer or any electrical or electronic circuit that can produce the same or a similar end result to that of the transformer; or again the converter may be a converter per se in which A.C. is changed to D.C. 
     Therefore, complexities associated with various voltage conversions are such that these conversions often provide a source of real annoyance and frustration to the traveler. Accordingly, a bi-voltage power converter is essential and mostly convenient for people who travel with their portable electrical devices between countries where the voltages and the plugging systems are different, which can also be useful in Duty-Free shops demos. However, current electronic transformers that can adjust themselves to the right voltage are relatively expensive. 
     In addition, there are also electro-mechanic transformers where an output voltage is in accordance to an input voltage. However, these transformers may be dangerous because a wrong connection could end in serious damage and safety problems. 
     SUMMARY OF THE INVENTION 
     Various objects and advantages of the invention will be set forth in part in the description that follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     To achieve the above and other objects, the present invention provides a power converter, including: a transforming unit including pins outwardly projecting from the transforming unit, and a socket; an adapter including a first plug mounted on a first side of the adapter, and a second plug mounted on a second side of the adapter, wherein the socket on the transforming unit receives the first plug or the second plug; pin cavities on the first side of the adapter, opposite to the second plug, providing a contact to receive the pins to allow the transformer unit to convert an input voltage to an output voltage; and pin cavities on the second side of the adapter, opposite to the first plug, providing a contact to receive one of the pins of the transformer unit to allow the transformer to convert the input voltage to the output voltage. 
     The present invention provides a power converter, including: a transforming unit including pins outwardly projecting from the transforming unit, a socket, and a transformer; an adapter including a first plug mounted on a first side of the adapter, and a second plug mounted on a second side of the adapter, wherein the socket on the transforming unit receives the first plug or the second plug; pin cavities on the first side of the adapter, opposite to the second plug, providing a contact to receive one of the pins tapping to a primary coil of a first voltage of the transformer to allow the transformer to convert a first input voltage to an output voltage; and pin cavities on the second side of the adapter, opposite to the first plug, providing a contact to receive one of the pins tapping to a primary coil of a second voltage of the transformer to allow the transformer to convert a second input voltage to the output voltage. 
     To achieve the above and other objects, the present invention further provides a power converter, including: a transforming unit including pins outwardly projecting from the transforming unit, a socket, and a transformer; an adapter including a first plug mounted on a first side of the adapter, and a second plug mounted on a second side of the adapter, wherein the socket on the transforming unit receives the first plug or the second plug; pin cavities on the first side of the adapter, opposite to the second plug, providing a contact to receive one of the pins tapping to a primary coil of about 220-volts of the transformer to allow the transformer to convert an input voltage of about 110-volts to a low DC output voltage; and pin cavities on the second side of the adapter, opposite to the first plug, providing a contact to receive one of the pins tapping to a primary coil of about 110-volts of the transformer to allow the transformer to convert an input voltage of about 220-volts to the low DC output voltage. 
    
    
     These together with other objects and advantages, which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objective and advantage of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which: 
     FIG. 1 illustrates a transforming unit in accordance with an embodiment of the present invention; 
     FIG. 2 illustrates a side view of an adapter in accordance with an embodiment of the present invention; 
     FIG. 3 illustrates the adapter installed on the transformer unit where a first plug on a first side of the adapter is connected to an external power source; 
     FIG. 4 illustrates a transformer in the transformer unit and the adapter installed on the transformer unit, where the first plug on the first side of the adapter is connected to the external power source; 
     FIG. 5 illustrates the adapter installed on the transformer unit where a second plug on a second side of the adapter is connected to the external power source; 
     FIG. 6 illustrates the transformer in the transformer unit and the adapter installed on the transformer unit, where the second plug on the second side of the adapter is connected to the external power source; and 
     FIG. 7 illustrates the transformer in the transformer unit and the adapter installed on the transformer unit. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. 
     FIG. 1 illustrates a transforming unit  10  in accordance with an embodiment of the present invention. In FIG. 1, on a front side of the transforming unit  10 , a socket  12  is shown adapted to receive a 220-volt plug or 110-volt plug. The transforming unit  10  also includes a pair of locking members  14  that provide a locking mechanism to engage an adapter  20  (to be later described) to the transforming unit  10  and maintain the adapter  20  in a fixed position. Three pins  16  protrude from a surface of the transforming unit  10 . Although three pins  16  are shown in this embodiment, the number of pins  16  of the transforming unit  10  may vary. As shown in FIG. 1, the pins  16  may be installed on one end of the front side of the transforming unit  10 , the socket  12  may be installed at another end of the front side of the transforming unit  10 , and the locking members  14  therebetween. 
     The pins  16 , depending on the type of plug being connected to the socket  12  on the transforming unit  10 , connect or tap primary coils of a transformer (not shown) in the transforming unit  10 . One pin connects to a common of the transformer, another pin connects or taps to the primary coil of about 120 volts, and another pin connects or taps to the primary coil of about 230 volts to provide 110 volts or 220 volts. That is, the pins  16  allow a physical change of entries of the transformer&#39;s primary coils to change an output of the transformer to a low DC output voltage between 3 to 9 volts, for instance. The transformer  10  may receive a variable AC input voltage ranging from about 100 volts to about 240 volts. The transforming unit  10  includes an AC/DC voltage conversion circuitry where the transforming unit  10  would receive a high voltage AC input through the adapter  20  and convert the AC input to a low DC output voltage. The transforming unit  10  provides at an end  18  an operating low DC voltage supply to an electrical apparatus, for instance, connected thereto. 
     FIG. 2 illustrates a side view of the adapter  20  in accordance with an embodiment of the present invention. As shown in FIG. 2, the adapter  20  is formed as a plate having a predetermined thickness including a 110-volt plug  22 , a 220-volt plug  24 , pin cavities  26 ,  28  on opposite ends of each plug, and a pair of locking recesses  30 . A shape of the 220-volt plug and a shape of the 110-volt plug have been adapted to be insertable into the socket  12  of the transforming unit  10 . Further, although the socket  12  is designed to accommodate the first and second plugs  22 ,  24  including extended flat pin pair or cylindrical pin pair, an extendable and retractable cylindrical pin pair or three extended flat pins may be adapted to be insertable into the socket  12  of the transforming unit  10 . 
     The 220-volts plug (i.e., a first plug)  24  includes a pair of cylindrically shaped terminals for high voltage, of about 220 volts, and outwardly disposed on a first side  32  and at one end of the adapter  20 . The 110-volts plug (i.e., a second plug)  22  includes a pair of elongated rectangular shaped terminals for low voltage, of about 110 volts, and outwardly disposed on a second side  34 , opposite to the first plug  24 , and at another end of the adapter  20 . The pair of locking recesses  30  is place between the first plug  24  and the second plug  22  to interlock with the locking members  14  of the transforming unit  10 . 
     FIG. 3 illustrates the adapter  20  installed on the transformer unit where the first plug  24  (i.e., 220-volts plug) is connected to an external power source, such as a wall socket. The second side  34  of the adapter  20  is facing the transforming unit  10  and the second plug  22  (i.e., 110-volts plug) is plugged into the socket  12  on the transforming unit  10 . The locking members  14  lock the adapter  20  to the transforming unit  10 . 
     Further, the pins  16  on the transforming unit  10  plug into the pin cavities  26  on the second side  34  of the adapter  20 , opposite to the first plug  24 . The pin cavities  26  provide a contact, for instance, to connect to one of the pins  16  tapping to the primary coil of about 220-volts of the transformer in the transforming unit  10 ; thus, allowing the transformer to convert an input voltage of about 220-volts, for instance, and to supply a low DC output voltage. Another contact may be provided in the pin cavities  26  to connect to the common of the transformer. In an alternative embodiment, contacts may be use as a combination unit of the pins  16  on the transforming unit  10  and the pin cavities  26 ,  28  on the adapter. 
     FIG. 4 illustrates the transformer in the transformer unit  10  and the adapter  20  installed on the transformer unit, where the first plug on the first side of the adapter is connected to the external power source. In one example, on a primary side of the transformer in the transformer unit  10 , one pin  42  would connect or tap to the primary coil of about 220 volts and another pin  44  would connect or tap to the common of the transformer to allow a physical change of entries of the transformer&#39;s primary coils to change an output of the transformer. The transforming unit  10  includes an AC/DC voltage conversion circuitry where the transforming unit  10  would receive the 220 volts AC through the adapter  20  and convert the 220 volts into a low voltage DC output voltage of using a conventional AC/DC voltage conversion bridge circuitry, for instance. 
     Furthermore, FIG. 5 illustrates the adapter  20  installed on the transformer unit where the second plug  22  on the second side  34  of the adapter  20  is connected to the external power source. The first side  32  of the adapter  20  is facing the transforming unit  10  and the first plug  24  is plugged into the socket  12  on the transforming unit  10 . The locking members  14  lock the adapter  20  to the transforming unit  10 . 
     Further, the pins  16  on the transforming unit  10  plug into the pin cavities  28  on the first side  32  of the adapter  20 , opposite to the second plug  22 . The pin cavities  28  provide a contact, for instance, to connect to one of the pins  16  tapping to the primary coil of about 110-volts of the transformer in the transforming unit  10 ; thus, allowing the transformer to convert an input voltage of about 110-volts, for instance, and to supply the low DC output voltage. Another contact may be provided in the pin cavities  28  to connect to the common of the transformer. 
     FIG. 6 illustrates the transformer in the transformer unit and the adapter installed on the transformer unit, where the second plug on the second side of the adapter is connected to the external power source. In one example, on the primary side of the transformer in the transformer unit  10 , one pin  46  would connect or tap to the primary coil of about 110 volts and another pin  44  would connect or tap to the common of the transformer to allow a physical change of entries of the transformer&#39;s primary coils to change an output of the transformer. The transforming unit  10  includes an AC/DC voltage conversion circuitry where the transforming unit  10  would receive the 110 volts AC through the adapter  20  and convert the 220 volts into a low voltage DC output voltage of using a conventional AC/DC voltage conversion bridge circuitry, for instance. 
     FIG. 7 illustrates the transformer in the transformer unit and the adapter installed on the transformer unit. On a primary side  50  of the transformer in the transformer unit  10 , one pin  42  connects to the primary coil of about 220 volts, another pin  46  connects to the primary coil of about 110 volts, and another pin  44  connects to the common of the transformer. On a secondary side  52  of the transformer, the AC/DC voltage conversion bridge circuitry is provided. Further, a switch  55  may be coupled to the secondary side of the transformer allowing a user to select a low DC output voltage of, for instance, 3 volts, 4.5 volts, 6 volts, or 9 volts DC, depending on the electrical apparatus to be connected to the transforming unit  10 . 
     As shown in FIGS. 3 and 5, the pin cavities  26 ,  28  are at one end of the adapter  20  configured to allow a secondary voltage of the transformer in the transforming unit  10  to be a low DC output voltage. Accordingly, the dual voltage power converter, in accordance with an embodiment of the present invention, provides a reliable, safe, and inexpensive device. The converter is standard, portable, and flexible to accommodate to different power supplies around the world. 
     Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.