Abstract:
An uninterruptible power supply system (UPS) and a power management method thereof suitable for an audio visual apparatus are provided. The uninterruptible power supply system includes a power management unit, a wireless transceiver module and a current detecting unit, wherein the current detecting unit is coupled to an output of the power management unit to detect a load current output from the UPS system. The UPS is capable of receiving and learning a wireless command code in an infrared ray (IR) remote control signal. When the UPS system detects a multimedia system connected thereto is turned on and the UPS system is in a lower power state, the UPS system sends command code to turn off the multimedia system to avoid the damage of the multimedia system during power failure.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to an uninterruptible power supply system, and more particular to an uninterruptible power supply system and a power management method suitable for an audio visual apparatus. 
     2. Description of Related Art 
     Uninterruptible power supply systems (UPS hereafter) are mainly classified into three types: on-line UPS, off-line UPS and line-interactive UPS. Recently, more and more audio visual apparatuses are provided with complicated operation and network functions maintained by stable power supply which are accomplished by the UPS. Since the power supply period of the UPS is usually limited, if the audio visual apparatus cannot be turned off within the power supply period of the UPS, damage may occur. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide an UPS and a power management method suitable for an audio visual apparatus. When the mains (also called commercial power or line power) fails, if the audio visual apparatus is on and a battery status of the UPS reaches a default value, the UPS sends a command code via a wireless transceiver module to control the audio visual apparatus. 
     In one aspect, when the UPS detects the audio visual apparatus being on and the battery status reaches the default value, the UPS sends a second command code to turn off the audio visual apparatus so that the audio visual apparatus may be turned off before the battery energy runs out. 
     In another aspect, when the UPS detects the recovered mains, the UPS sends the second command code again to reboot the audio visual apparatus and supply power to the audio visual apparatus. 
     Yet, in another aspect, the UPS of the invention is applicable for all types of remote controllers. Once the remote controller sends a command code, the UPS is booted without exceptions. 
     The power management method of the invention prevents the audio visual apparatus being turned off when the audio visual apparatus is still on. 
     For further understanding of the present invention, reference is made to the following detailed description illustrating the embodiments and examples of the present invention. The description is for illustrative purpose only and is not intended to limit the scope of the claim. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing the first embodiment of a UPS of the invention for an audio visual apparatus; 
         FIG. 2  is a block diagram showing the second embodiment of a UPS of the invention for an audio visual apparatus; 
         FIG. 3  is a block diagram showing the third embodiment of a UPS of the invention for an audio visual apparatus; 
         FIGS. 4 to 6  are float charts of an embodiment of a power management method of the invention; and 
         FIG. 7  is a float chart of another embodiment of a power management method of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     Referring to  FIG. 1 , an UPS  110  is disposed between an audio visual apparatus  130  and an AC power source (AC IN). 
     The UPS  110  includes a power management unit  120 , a wireless transceiver module  114  and a current detecting unit  112 . The power management unit  120  is coupled to the wireless transceiver module  114  and the current detecting unit  112  and receives power from the AC power source (AC IN). The power management unit  120  further comprises an AC/DC converter  122 , a DC/AC converter  124 , a battery  126 , a control unit  128  and a switch  129 . The battery  126  is coupled to the AC/DC converter  122  and the DC/AC converter  124 . The switch  129  is coupled to an output of the DC/AC converter  124 , the current detecting unit  112  and the AC power source (AC IN) and controlled by the control unit  128  to switch power supply mode. The control unit  128  is coupled to the AC/DC converter  122 , the DC/AC converter  124 , the switch  129 , the current detecting unit  112  and the wireless transceiver module  114 . 
     The AC/DC converter  122  converts the AC power to DC power and charges the battery  126 . The DC power is converted to AC power by the DC/AC converter  124  and output to an audio visual apparatus  130  via a power output port  127 . The current detecting unit  112  and the switch  129  are between the DC/AC converter  124  and power output port  127 . The switch  129  is, for example, a three-ends switch element or a multiplexer and controlled by a control unit  128  to switch power supply routes. Thus, the output power of the UPS  110  may selectively from the AC power source or converted from the battery  126 . The current detecting unit  112  detects load current output from the UPS  110 , which is also the consumed current of the audio visual apparatus  130 . The power management unit  120  determines that the audio visual apparatus  130  is on or off according to the detected load current. For example, when the load current output from the UPS  110  exceeds a default value, it is indicated that the audio visual apparatus  130  is on. When the load current is zero or smaller than the default value, it is indicated the audio visual apparatus  130  is off. 
     The wireless transceiver module  114  is, for example, an infrared module, a RF module, a RF4CE module or a Bluetooth module to receive control signals from a controller  140  and send control signals to control the audio visual apparatus  130 . In this embodiment, a first command code and a second command code are saved in the UPS  110 . The first command code is used to control the UPS  110  on and off, and the second command code is used to control the audio visual apparatus  130  off. The first and second command codes can be defined and saved in the control unit  128  by a manufacturer in advance, input manually by a user. The first and second command codes can also be defined by a user or learned by the UPS  110  via the wireless transceiver module  114  from a remote controller  140  operated by a user and saved in the control unit  128 . The UPS  110  is controlled to be on or off according to the first command code from the remote controller  140  operated by a user. 
     When the UPS  110  is turned on, the UPS  110  provides power for the audio visual apparatus  130 . When the AC power source fails, if the UPS  110  detects the audio visual apparatus  130  being on and the status of battery  126  reaches a default value, the UPS  110  sends the second command code with the wireless transceiver module  114  to turn off the audio visual apparatus  130 . At this time, since the UPS  110  is still on, the audio visual apparatus  130  has enough time to be turned off before the energy of the battery  126  runs out. For example, the control unit  128  detects the battery  126 . When the voltage of the battery  126  is reduced to a default value or the battery  126  provides energy for a default period, the control unit  128  sends a second command code with the wireless transceiver module  114 . When the current detecting unit  112  detects the audio visual apparatus  130  being turned off, the UPS  110  is turned off. 
     The control unit  128  is, for example, a microprocessor having data storage function to perform the described procedure. In fact, the procedure can be performed by a firmware. The embodiment is not limited to it. 
     Second Embodiment 
     Referring to  FIG. 2 ,  FIG. 2  is a diagram showing the second embodiment of a UPS of the invention for an audio visual apparatus. The UPS  110  has a plurality of power output port  127  to supply power to a plurality of audio visual apparatuses  130 ˜ 139 . The current detecting unit  112  detects the load current of the UPS  110 . The power management unit  120  determines that the audio visual apparatuses  130 ˜ 139  are on or off according to the detected load current. The UPS  110  has a first command code codes and a plurality of second command codes. The first command code controls the UPS  110  on or off, and the second command codes control the audio visual apparatuses  130 ˜ 139  off. The first and second command codes can be defined by a manufacturer in advance. The first and second command codes can also be defined by a user or learned by the UPS  110  via a wireless transceiver module  114  from a plurality of remote controllers  140 ˜ 149  operated by a user. The UPS  110  is controlled to be on or off according to the first command code from the remote controller  140 . When the UPS  110  detects the audio visual apparatuses  130 ˜ 139  being off and the battery  126  has low power, the UPS  110  sends the second command codes to turn off the audio visual apparatuses  130 ˜ 139  one by one. At this time, since the UPS  110  is still on, the audio visual apparatus  130  has enough time to be turned off before the energy of the battery  126  runs out. 
     In addition, in this embodiment, a plurality of current detecting units  112  is provided. For example, the current detecting units  112  are connected to the output of the power output ports  127  respectively. The power management unit  120  determines that the audio visual apparatuses  130 ˜ 139  are on or off according to the load currents detected by the current detecting units  112 . When the current detecting unit  112  detects the corresponding audio visual apparatus  130  being on and the battery  126  has low power, the UPS  110  sends the second command codes with the wireless transceiver module  114  to turn off the audio visual apparatuses  130 . When the current detecting unit  112  detects the audio visual apparatuses  130 ,  131 ,  139  being on and the battery  126  has low power, the UPS  110  sends the second command codes to turn off the audio visual apparatuses  130 ,  131  and  139  one by one. 
     Third Embodiment 
     The structure of the power management unit is not limited to  FIG. 1 , wherein the power management unit  120  comprises an on-line UPS or line-interactive UPS.  FIG. 3  shows the third embodiment of a UPS of the invention for an audio visual apparatus. The AC power source of the power management  320  is not coupled to the switch  129 . The power output of the UPS  310  is through the AC/DC converter  122  and DC/AC converter  124  to provide stable power. 
     Fourth Embodiment 
     The invention can be summarized as a first power management method. Referring to  FIGS. 4-6 ,  FIGS. 4 to 6  are float charts of the fourth embodiment of a power management method of the invention. In the step S 420 , the UPS  110  is booted manually or by the first command code sent from the remote controller  140 . In the step S 421 , the UPS  110  provides power to the audio visual apparatuses  130  from the mains. In the step S 422 , the control unit  128  determines that the mains fails or not. If the mains does not fail, the step S 421  continues. If the mains fails, then enter the step S 430 , wherein the audio visual apparatuses  130  is powered by the battery  126 . In the step S 440 , the current detecting unit  112  detects the load to determine the audio visual apparatuses  130  is on or off. If no load is detected, then enter the step S 490 , wherein the UPS  110  is turned off automatically. If the load is detected, then enter the step S 450 , wherein the control unit  128  determines if the status of battery  126  reaches a default value, for example, the battery voltage is lower than a value or the power supply continues a predetermined period. If the default is not reached, then the step S 430  continues. If the default value is reached, then enter the step S 461 , wherein the control unit  128  sends the first command code with the wireless transceiver module  114  to turn off the audio visual apparatus  130 . At this time, the audio visual apparatus  130  is powered by the battery  126 . 
     Referring to  FIGS. 1 and 5 , the power management method may further comprise a step S 492  before the step S 490 , wherein it enters S 490  after T seconds. When no load is detected, the control unit  128  may save the number of the control unit  128  sending the second command code in T seconds, record the power supply data, failure period of mains or battery condition of the battery  126 . 
     Referring to  FIGS. 1 and 6 , the power management method further comprises a step S 431  between the step S 430  and S 440  to determine if the mains is repowered. If the mains are repowered, then enter the step S 460  to determine if the second command code is sent. If the second command code is never sent, which means that the audio visual apparatus  130  is still on, then enter the step S 421 , wherein the audio visual apparatus  130  is powered by mains. If the second command code is already sent, then enter the step S 462 , wherein the control unit  128  sends the second command code again to reboot the audio visual apparatus  130 , and the step S 421  continues, wherein the audio visual apparatus  130  is powered by mains. 
     This embodiment is applicable to all types of remote controller, for example, in the step S 420 , once a remote controller sends a command code, the UPS  110  is booted without exception. 
     Fifth Embodiment 
     The invention can also be summarized as a second power management method. Referring to  FIGS. 1 and 7 , the remote controller  140  cannot turn off the UPS  110  when the audio visual apparatus  130  is still on. In the step S 410 , the remote controller  140  sends a first command code. In the step S 420 , the UPS  110  is booted according to the first command code (for the first time). In the step S 480 , the remote controller  140  sends a first command code again (for the second time). At this time, the UPS  110  is not turned off immediately, and it enters the step S 441  to detect if the load exits to determine if the audio visual apparatus  130  is on. If no load is detected, then enter the step S 490  to turn off the UPS  110 . If the load is detected, then enter the step S 463 , wherein the control unit  128  sends the second command code via the wireless transceiver module  114  to turn off the audio visual apparatus  130  first, and next enter the step S 470  to wait until the audio visual apparatus  130  is turned off. Then enter the step S 442  to detect the load with the current detecting unit  112 . If no load is detected, then enter the step S 490  to turn off the UPS  110 . If the load is detected, then enter the step S 470 , wherein the UPS  110  is on until the audio visual apparatus  130  is turned off. 
     The description above only illustrates specific embodiments and examples of the present invention. The present invention should therefore cover various modifications and variations made to the herein-described structure and operations of the present invention, provided they fall within the scope of the present invention as defined in the following appended claims.