Abstract:
This invention relates to an always-on uninterrupted power supply system mainly provided with a control unit to govern a power supply switch unit. When one of main power supply units or a bypass power supply unit of an external power device is to be installed or uninstalled for maintenance, a user can operate the control unit to enable the power supply switch unit to switch to the main power supply unit or the bypass power supply unit that is not to be installed or uninstalled to provide power for loads connected with the always-on uninterrupted power supply system to operate continuously, without interrupting the normal operation of the load.

Description:
[0001]    The current application is a continuation-in-part of, and claims a priority to U.S. Ser. No. 11/841,656 filed on Aug. 20, 2007. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to a system for uninterrupted power supply, particularly to one being able to supply power to those electric loads connected to the system to continuously supplied with power without being interrupted. 
         [0004]    2. Description of the Prior Art 
         [0005]    It is known that people rely more and more on information technology products in their daily life and there is always a demand for a stable power supply to those products.  FIG. 1  shows a block diagram of a conventional way in electric circuit of a load  1 . A conventional uninterruptible power system  3 , generally referred as a UPS, is connected between the load  1  and the external power supply  2  so as to enable the load  1  can be normally shut down with sufficient time because of a sudden break down of an external power supply  2 . The load  1  can be booted again as soon as the external power supply  2  is restored to supply power. However, if the interruptible power system  3  is out of function and becoming functional abnormal and have to be disassembled for a repair, it can not be disconnected until the load  1  is completely shut down. In addition, the load  1  must be connected to another external power supply or other spare power supply before the interruptible power system  3  is repaired if the load  1  has to be operated continuously. It is apparently to see the load  1  has to be switched OFF and resumed ON during an unexpected power failure. There was no system to supply electric power to a load continuously even when a UPS is out of function or in need of maintenance. Therefore, by using a conventional UPS  3  may cause not only inconvenience to a user, but also a raise of cost and a waste of time by interruption of the normal operation of the load. 
         [0006]    In U.S. Pat. No. 6,191,500, there is disclosed a system for providing uninterrupted power supply to a critical load. In the disclosure, the system contains two power uninterrupted modules to make sure the output powers from them can be combined with one another to provide a sufficient source of power to the critical load regardless of the phase difference. This invention has no teachings on if one of the modules is out of function and to be uninstalled. Therefore, it still can not meet the demand to permanently and continuously having power to be supplied to the load. 
       SUMMARY OF THE INVENTION 
       [0007]    It is therefore the primary object of the present invention to provide a system for uninterrupted power supply to a load when the UPS units is out of function or in need of uninstallation to continuously supply power to the connected load. 
         [0008]    The main advantage of the system for uninterrupted power supply is to save time and inconvenience of the users without being interrupted during the UPS unit is to be uninstalled. 
         [0009]    Another object of the present invention is to provide an always-on system so that the power supply to the load is always on without any interruption. 
         [0010]    It is therefore the system for uninterrupted power supply according to the present invention comprises mainly a control unit to govern a power supply switch unit. The external power device has a main power supply unit and a bypass power supply unit. When the external power device is to be installed or uninstalled, the control unit can transmit an enabling signal to a power supply switch unit which being orderly connected with a protection circuit unit and a power supply input unit so as to select a main power supply input terminal or a bypass power supply input terminal of the power supply input unit to provide power for the system to keep loads connected with the always-on system continuing to work without being affected by installing or uninstalling the external power device. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]    This invention is better understood by referring to the accompanying drawings, wherein: 
           [0012]      FIG. 1  is a block diagram of a conventional connecting system relating to an external power supply, an uninterruptible power system (UPS) and a load; 
           [0013]      FIG. 2  is a simplified block diagram of a circuit connection used in a preferred embodiment of the always-on uninterrupted power system according to the present invention; 
           [0014]      FIG. 3  is a block diagram of an electric circuit of the preferred embodiment of an always-on uninterrupted power system according to the present invention; 
           [0015]      FIG. 4  is an illustrative diagram showing the always on uninterrupted power system according to the present invention being connected to various power loads; and 
           [0016]      FIG. 5  is a schematic circuit diagram of the always on uninterrupted power system according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    Referring to  FIGS. 2 and 3  which show a preferred embodiment of an always-on uninterrupted power system  100  in the present invention, the system  100  is connected to an external power device  200  at one side for providing diverse power supplies, and a plurality of loads  300  at the other end. The external power device  200  is provided with a main power supply unit  210  and a bypass power supply unit  220 . The always-on system  100  is mainly composed of a power supply input unit  10 , a protection circuit unit  20 , a power supply switch unit  30  and a control unit  40  as better shown in  FIG. 3 . 
         [0018]    The power supply input unit  10  is provided with a main power supply input terminal  11 , a bypass power supply input terminal  12  and a power supply asynchronous detecting circuit  13 , said main power supply input terminal  11  connected to said main power supply unit  210 , said bypass power supply input terminal  12  connected to said bypass power supply unit  220 , said power supply asynchronous detecting circuit  13  connected with the main power supply input terminal and the bypass power supply input terminal  12  respectively. The power supply asynchronous detecting circuit  13  is employed to detect if the phase of power supply transmitted from the main power supply unit  210  of the external power device  200  connected with the main power supply input terminal  11  is synchronous with that of another power supply transmitted from the bypass power supply unit  220  of the external power device  200  connected with the bypass power supply input terminal  12 . 
         [0019]    The protection circuit unit  20  connected with said power supply input unit  10  at its one side for protecting said load  300  from being damaged, the protection circuit unit  20  is composed of a first filtering circuit  21 , a delay protection circuit  22 , an abnormal protection circuit  23  and a second filtering circuit  24 . The first filtering circuit  21  is connected with the main power supply input terminal  11  and the bypass power supply input terminal  12  of the power supply input unit  10  respectively to isolate noise of surge and harmonic created inside said always-on system  100 , the delay protection circuit  22  is connected with the abnormal protection circuit  23 . 
         [0020]    The power supply switch unit  30  is connected with the first filtering circuit  21  at its one side and connected with said second filtering circuit  24  at its another side. When power supply is transmitted through the main power supply input terminal  11  connected with the main power supply unit  210 , the power supply switch unit  30  can switch to the bypass power supply input terminal  12  connected with the bypass power supply unit  220  to provide power through another power supply, keeping the loads  300  connected with the always-on system  100  operating continuously without any influence. It works on the contrary, as well. 
         [0021]    The control unit  40  is connected with the delay protection circuit  22  at its one side and connected with the power supply switch unit  30  at its another side, the control unit  40  able to select the main power supply input terminal  11  or the bypass power supply input terminal  12  to provide power to keep the load  300  operating continuously without being affected when one of the main power supply unit  210  and the bypass power supply unit  220  is being installed or uninstalled. 
         [0022]      FIG. 4  shows a first example of the preferred embodiment of the present invention in using, wherein the main power supply unit  210  of the external power device  200  is an uninterruptible power system (UPS) connected with the main power supply input terminal  11  of the always-on system  100 , and the bypass power supply unit  220  of the external power device  200  is an commercial power directly connected with the bypass power supply input terminal  12 . So, the loads  300  are operated by means of the power provided by the always-on system  100  connected therewith. If the main power supply unit  210  is found abnormal to be uninstalled, a user needs only to press down the control unit  40  of the always-on system  100  to make the power supply switch unit  30  switch to the bypass power supply input terminal  12  connected with the bypass power supply unit  220  to provide power for the loads  300  to keep on operating without being shut down for connecting with another power supply, affecting nothing of scheduled work. 
         [0023]    After the main power supply unit  210  has been fixed up, it can be directly connected with the main power supply input terminal  11 . Then, press down again the control unit  40  to make the power supply switch unit  30  switch back to the main power supply input terminal  11  connected with the main power supply unit  210  to provide power for the loads  300  to go on without being affected. In addition, if a user forgets to switch the bypass power supply input terminal  12  to the main power supply input terminal  11  after having the main power supply unit  210  connected with the main power supply input terminal  11  of the always-on system  100 , and the bypass power supply unit  220  stops providing power because of power cut or other unexpected reasons, the abnormal protection circuit  23  sends an enabling signal to the power supply switch unit  30  through the delay protection circuit  22  and the control unit  40 , the power supply switch unit  30  is to immediately switch to the main power supply input terminal  11  connected with the main power supply unit  210  (UPS) to provide power for the loads  300 , for preventing the loads  300  from damaged owing to man&#39;s carelessness. 
         [0024]      FIG. 5  shows a schematic circuit diagram of the always on uninterrupted power system of the present invention. The system mainly corresponds to the block diagram shown in  FIG. 4 . The circuit is an actual practiced one with function to achieve the desired ones according to the present invention. It is shown in the circuit, there are main power supply input terminal  11 , bypass power supply input terminal  12 , power supply asynchronous detecting circuit  13 , first filtering circuit  21 , delay protection circuit  22 , abnormal protection circuit  23 , second filtering circuit  24 , power supply switching unit  30 , and control unit  40  respectively and circuit connection as to the desired function of the always on uninterrupted power system according to the present invention. The power supply switch unit  30  in the preferred embodiment of the present invention is a switch circuit based on relays RY 1  and RY 2 , the control unit  40  in the preferred embodiment of the present invention is synchronous manually switch SW 1 . 
         [0025]    It is better understood with reference to this  FIG. 5  for the overall operation of the power switching unit  30 . The position of the switch SW 1  as shown in  FIG. 5  is in the bypass power status. The abnormal protection circuit  23  sends the enabling signal to the delay protection circuit  22 , so that the transistor Q will be cut off. The power supply switch unit  30  can automatically switch to the main power supply input terminal  11  connected with the main power supply unit  210  to provide power through another power supply, keeping the loads  300  connected with the always-on system  100  operating continuously without any influence. 
         [0026]    If we need to maintain a certain power supply device as specified in block  200  of  FIGS. 2 and 3 , such as a conventional UPS, we can switch manually. The switch SW 1  can be operated manually to switch the power supply either from main power supply unit  210  or bypass power supply unit  220  through the corresponding terminals  11  and  12  respectively, particularly in need to uninstall the UPS. 
         [0027]    While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.