Abstract:
Systems and methods for isolating an electric powered device from power surges are provided. In this regard, a representative system, among others, includes a switch that electrically couples AC signals from an AC source to an electric powered device and a surge voltage detector that is electrically coupled to the switch. The surge voltage detector is configured to receive the AC signals and detect power surges in the AC signals. Responsive to detecting a power surge in the AC signals, the surge voltage detector is configured to open the switch, thereby isolating the power surge in the AC signals from the electric powered device.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of copending EP application having ser. no. EP07301183, filed Jun. 29, 2007, which is entirely incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to alternating-current (AC) signals, and more particularly, the disclosure relates to systems and methods for isolating power surges in the AC signals from an AC source. 
       BACKGROUND 
       [0003]    Some countries, typically in third world countries, have unstable alternating-current (AC) power sources. The unstable AC power sources include power surges that can damage electric powered devices, such as, for example, computers, monitors, printers and appliances, among others. Prior solutions have been incorporated in power supplies to address the unstable AC power sources; however, this makes electric powered devices more expensive. 
       SUMMARY 
       [0004]    Systems and methods for isolating an electric powered device from power surges are provided. In this regard, a representative system, among others, includes a switch that electrically couples AC signals from an AC source to an electric powered device and a surge voltage detector that is electrically coupled to the switch. The surge voltage detector is configured to receive the AC signals and detect power surges in the AC signals. Responsive to detecting a power surge in the AC signals, the surge voltage detector is configured to open the switch, thereby isolating the power surge in the AC signals from the electric powered device. 
         [0005]    A representative method, among others, for isolating an electric powered device from power surges in AC signals comprises: receiving AC signals from an AC source; determining whether a power surge is present in the AC signals; and responsive to determining that the power surge is present in the AC signals, isolating the power surge in the AC signals from the electric powered device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0007]      FIG. 1  is a system overview that includes a surge protector. 
           [0008]      FIG. 2  is a high-level block diagram that illustrates an embodiment of the surge protector, such as that shown in  FIG. 1 . 
           [0009]      FIG. 3  is a detailed block diagram that illustrates an embodiment of the surge protector, such as that shown in  FIG. 1 . 
           [0010]      FIG. 4  is a high-level flow diagram that illustrates an embodiment of the architecture, functionality, and/or operation of the surge protector, such as that shown in  FIG. 1 . 
           [0011]      FIG. 5  is a detailed flow diagram that illustrates an embodiment of the architecture, functionality, and/or operation of the surge protector, such as that shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Exemplary systems are first discussed with reference to the figures. Although these systems are described in detail, they are provided for purposes of illustration only and various modifications are feasible. After the exemplary systems are described, examples of flow diagrams of the systems are provided to explain the manner in which power surges in alternating-current (AC) signals are isolated. 
         [0013]      FIG. 1  is a system overview that includes a surge protector. An AC source  105  generates and transmits AC signals to a building  110  via line  107 . The building  110  includes an outlet  115  that is electrically coupled to the AC source  105 . A surge protector  120  can be electrically coupled to the outlet  115  via line  117 . Electric powered devices  125  can be coupled to the surge protector  120  via line  123 , to receive the AC signals from the AC current source  105 . Generally, the surge protector includes a plug (not shown) that can be connected to the outlet  115  and at least one socket (not shown) that facilitates electrical connection to the electric powered devices  125 . The electric powered devices  125  include, but are not limited to, computing devices  130 , monitors  135 , printers  140 , and appliances  145 , among others. 
         [0014]      FIG. 2  is a high-level block diagram that illustrates an embodiment of the surge protector, such as that shown in  FIG. 1 . AC signals are received at line  117  and transmitted to a transformer  210  and a turn-off switch  250 . The transformer  210  is configured to transform the voltage of the AC signals to a certain value that can be processed by the surge protector  120 . The transformer  210  is further configured to isolate electronic components associated with the surge protector  120  from the actual connection to the AC source  105 . The electronic components associated with the surge protector  120  include, but are not limited to, a surge voltage detector  230 , a delay element  240  and a voltage regulator  260 , among others. 
         [0015]    The transformer  210  provides the transformed AC signals to a low power bias circuit  220 , which generates power for electrical components of the surge protector  120 . The transformer  210  also provides the transformed AC signals to the surge voltage detector  230 , which detects whether power surges are present in the AC signals. If the surge voltage detector  230  detects that the power surges are not present in the AC signals, the turn-off switch  250  remains close and continues to pass the received AC signals from line  117  to line  255 . If the surge voltage detector  230  detects that the power surges are present in the AC signals, the surge voltage detector  230  transmits a turn-off signal to the delay element  240 , which instructs the turn-off switch  250  to open disconnecting the AC signals from line  117  to line  255 . The functionality of the surge voltage detector  230  is described in relation to  FIGS. 4 and 5 . 
         [0016]    The delay element  240  is configured to determine a period of time the turn-off switch  250  should stay open based on the detected power surges in the AC signals. If the period of time that the turn-off switch  250  has stayed open has passed, the delay element  240  instructs the turn-off switch  250  to close thereby passing the received AC signals from line  117  to line  255 . Alternatively or additionally, the delay element  240  and the turn-off switch  250  are electrically coupled to the voltage regulator  260  via lines  247 ,  255 , respectively. The delay element  240  instructs the voltage regulator  260  to provide a certain voltage to an AC socket  270  via line  265  based on the detected power surges in the AC signals or the open or close status of the turn-off switch  250 . The functionality of the delay element  240  is described in relation to  FIG. 5 . Alternatively or additionally, the turn-off switch  250  can be electrically coupled to the AC socket  270  without the voltage regulator  260 . The AC socket  270  passes the AC signals via lines  123  to the electric powered devices  125  with little to no power surges. 
         [0017]      FIG. 3  is a detailed block diagram that illustrates an embodiment of the surge protector, such as that shown in  FIG. 1 . AC signals are received at line  117  generally by way of a plug  303  that can be electrically connected to the outlet  115  of the building  110 . The AC signals are transmitted to switches  314 ,  315  and transformer  316  via lines  306 ,  307 ,  308 ,  309 ,  310 ,  311 , respectively. The transformer  316  includes an adjustable tap  313  on the secondary coil of the transformer  316  that can change the received AC signals to a certain value. 
         [0018]    The changed AC signals are transmitted to diodes  326 ,  329 ,  346 ,  349  via lines  319 ,  323 ,  339 ,  343 , respectively. The diodes  326 ,  329  rectify the AC signals and transmit the rectified AC signals to a capacitor ground combination  333  which can generate a low power bias at node  336 . The low power bias can be used as a power source by electrical components of the surge protector  120 . 
         [0019]    The rectified AC signals from the diodes  346 ,  349  are transmitted to a comparator  376  and a resister ground combination  353  via line  356 . The comparator  376  receives a Vref signal at node  366  between resistors  363 ,  369 . The Vref signal is determined based on the value of the Vset signal at node  359  and resistors  363 ,  369 . The resistor  369  is electrically coupled to ground  373 . The Vref value at node  366  can be adjusted by changing the values of the Vset signal at node  359  and the resistors  363 ,  369 . The comparator  376  generates and transmits a turn-off signal via line  383  based on the AC signals surpassing the Vref value. At node  379 , the turn-off signal is generated based on the magnitude of the AC signal surpassing the Vref value or a threshold value, such as that shown in an exemplary graph at node  379 . The functionality of the comparator  376  is described in relation to  FIGS. 4 and 5 . 
         [0020]    The turn-off signal is received by a delay element  386  via line  383 . The delay element  386  transmits a command to at least one turn-off switch  314 ,  315  via lines  389 ,  390 , respectively, instructing the switches  314 ,  315  to open thereby no AC signals are passed from the plug  303  to sockets  392 ,  399 , respectively. Alternatively or additionally, a voltage regulator  396  is electrically coupled between the switch  315  and socket  399 A. The voltage regulator  396  is configured to receive command signals from the delay element  386  via line  391  to transmit a certain voltage to the electric powered devices  125  based on the detected power surges. 
         [0021]    Alternatively or additionally, the delay element  386  can provide a status signal to a display element  387  via line  385 . The status signal includes signals for power outage, power surges, and normal AC signal, among others. The display element  387  includes, for example, a green light indicating normal AC signal activities, red light for power surges, and no light for power outage, among others. The AC signals are passed through the surge protector  120  at nodes  123 A,  123 B via sockets  392 ,  399 , respectively, to the electric powered devices  125 . The functionality of the delay element  386  is described in relation to  FIG. 5 . 
         [0022]      FIG. 4  is a high-level flow chart that illustrates an embodiment of the architecture, functionality, and/or operation of the surge protector  120 , such as that shown in  FIG. 1 . The surge protector  120  receives AC signals, such as that shown at step  405 . Step  410  determines whether power surges are present in the received AC signals, and responsive to determining that power surges are present in the received AC signals, step  420  isolates power surges in the AC signals from the electric powered devices  125 . If the power surges are not detected, step  415  passes the received AC signals to the electric powered devices  125 . 
         [0023]      FIG. 5  is a detailed flow diagram that illustrates an embodiment of the architecture, functionality, and/or operation of the surge protector  120 , such as that shown in  FIG. 1 . The surge protector  120  receives AC signals from an AC source  105  at step  505 . Step  510  changes the AC signals to a certain value. Step  515  determines whether power surges are present in the AC signals. If the power surges are not present, step  523  continues to close switches  314 ,  315 , such as that shown in  FIG. 3 , to pass the received AC signals to the electric powered devices  125 . If the power surges are present, step  520  generates and transmits turn-off signals to open the switches  314 ,  315  thereby isolating the power surges in the AC signals from the electric powered devices. 
         [0024]    Step  525  determines a period of time that the switches  314 ,  315  should stay open to isolate the received AC signals from the electric powered devices. Step  530  continues to open the switches  314 ,  315  according to the determined period of time. Step  535  determines whether the period of time has passed in relation to closing the switches  314 ,  315  based on the detected power surges. If the determined period of time has not passed, step  530  continues to open the switches  314 ,  315 . If the determined period of time has passed, step  540  closes the switches  314 ,  315 , which, in turn, passes the received AC signals without the power surges to the electric powered devices  125 . Alternatively or additionally, the determined period of time in relation to closing the switches  314 ,  315  can be longer than the occurrence of the power surges. 
         [0025]    Alternatively or additionally, step  545  generates and passes a certain voltage to the electric powered devices based on the detected power surges rather than providing no voltage to the electric powered devices as implied at step  530 . Alternatively or additionally, step  545  can regulate voltage based on the open and close state of the switch. Alternatively or additionally, step  545  can regulate voltage to the electric powered devices  125  according to the determined period of time. 
         [0026]    It should be noted that any process descriptions or blocks in flowcharts should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process. As would be understood by those of ordinary skill in the art of the software development, alternate embodiments are also included within the scope of the disclosure. In these alternate embodiments, functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved. 
         [0027]    This description has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments discussed, however, were chosen to illustrate the principles of the disclosure, and its practical application. The disclosure is thus intended to enable one of ordinary skill in the art to use the disclosure, in various embodiments and with various modifications, as is suited to the particular use contemplated. All such modifications and variation are within the scope of this disclosure, as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly and legally entitled.