Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a power signal detecting system and method, and more particularly to a power signal detecting system and method capable of reducing the frequency of the CPU. 
     2. Description of the Related Art 
     With technological developments, notebook computers have become very popular electronic products in modern life. Due to manufacture cost consideration, usually the notebook computer is paired with a power supply supplying low power watts. However, for the performance and safety, the notebook computer system needs to be paired with a proper power supply. If the notebook computer system is connected to a power supply supplying inefficient power; for example, when a 90 watts power notebook computer system is connected to a power supply supplying 65 watts power, the performance and safety of the notebook computer system might be affected, and the power supply might also be damaged. 
     In prior art technology, a charger IC in the notebook computer system maybe used for detecting the inputted power signal to detect the watts of the power signal. When the watts of the power signal is not enough, the charger IC can only protect the notebook computer system by stopping charging the power supply, it can not protect the power supply. Alternatively, another prior art technology disclosed the notebook computer system with a comparer which detects the inputted power signal. However, this causes higher manufacture cost. 
     Therefore, it is desirable to provide a power signal detecting system and method to mitigate and/or obviate the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     A main objective of the invention is to provide a power signal detecting system and a portable electronic device for identifying the power signal. 
     Another objective of the invention is to provide a method of detecting a power signal. 
     In order to achieve the above-mentioned objectives, the power signal detecting system of the invention comprises a power supply and a portable electronic device. The power supply may comprise an adapter. The portable electronic device is electrically connected with the power supply to receive a power signal. The portable electronic device comprises a sensing element, a detecting module, and a power management module. The power signal passes through the sensing element. The detecting module is electrically connected to the sensing element and is used for detecting the power signal. The power management module electrically connects to the detecting module and is used for executing a power management for the portable electronic device by recognizing the power signal. 
     The method of detecting the power signal of the invention comprises: inputting the power signal to pass through the sensing element; detecting the sensing element to generate a voltage signal; and performing a power management for the portable electronic device according to the voltage signal. 
     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a power signal detecting system according to the invention. 
         FIG. 2  is a flow chart of a method of detecting a power signal according to the invention. 
         FIG. 3A-3B  is a flow chart of a power management according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Please refer to  FIG. 1 .  FIG. 1  is a block diagram of a power signal detecting system according to the invention. 
     The power supply detecting system  1  comprises a portable electronic device  10  and a power supply  20 . The power supply  20  may comprise an adapter. The power supply  20  is connected to the portable electronic device  10  to provide a power signal to the portable electronic device  10 . The power supply detecting system  1  is used for detecting the watts of the power signal inputted by the power supply  20  to determine whether the power signal satisfies the setting of the portable electronic device  10 . 
     In one embodiment of the invention, the portable electronic device  10  is a notebook computer, a desktop computer, or a cellphone, but other devices can also be utilized. The portable electronic device  10  comprises a detecting module  11 , a power management module  12 , a sensing element  13 , a CPU  14 , and a timer  15 . The power signal inputted by the power supply  20  first passes through the sensing element  13 . In this embodiment, the sensing element  13  is a resistor, but the invention can have other various designs. The detecting module  11  can be a charger IC connected to the battery (not shown) in the portable electronic device  10 , but the invention can have other various designs. The detecting module  11  is electrically connected to the sensing element  13  and used for detecting the power signal passing through the sensing element  13 . Therefore, the detecting module  11  generates voltage signals. 
     The power management module  12  can be a keyboard controller (KBC), an embedded controller (EC) or a microprocessor. The power management module  12  is electrically connected to the detecting module  11  and used for calculating the watts of the power signal according to the voltage signal of the detecting module  11  and identifying the supplying watts of the power supply  20 . Afterward, a power management can be performed to the portable electronic device  10  based on the watts. For example, the frequency of the CPU  14  of the portable electronic device  10  is reduced to reduce the consuming watts of the portable electronic device  10 . The method for the power management will be described later. 
     Furthermore, the power management module  12  has a timer  15 . When the power supply  20  supplies the higher watts power signal, the power management module  12  increases the frequency of the CPU  14 . In order to prevent the power management module  12  from mistake determination, the power management module  12  utilizes the timer  15  to repeat its determination process. 
     Next, please refer to  FIG. 2 .  FIG. 2  is a flow chart of a method of detecting a power signal according to the invention. Even power signal detecting system  1  is utilized in the following description to explain the method of detecting the power signal, the method of detecting the power signal is not limited for being applied onto the power signal detecting system  1 . 
     First, the power supply  20  performs step  201 : inputting a power signal. 
     The power supply  20  supplies a power signal and inputs the power signal into the portable electronic device  10 . 
     Next, step  202  is performed: detecting the power signal passing through the sensing element  13  to generate a voltage signal. 
     The detecting module  11  detects the power signal passing through the sensing element  13 . In this embodiment, the sensing element  13  is a resistor, and the power signal generates a voltage drop when it passes through the sensing element  13 . The detecting module  11  detects the voltage drop and obtains a voltage signal. 
     Step  203  is performed by the portable electronic device  10 : identifying the power signal based on the voltage signal. 
     After obtaining the voltage signal from step  202 , the power management module  12  calculates the watts of the power signal supplied by the power supply  20 . 
     Finally, step  204  is performed: performing a power management to the portable electronic device. 
     After obtaining the watts supplied by the power supply  20 , the power management module  12  performs the power management to the portable electronic device  10  according to the watts supplied by the power supply  20 . Therefore, the portable electronic device  10  or the power supply  20  can prevent from the short circuit or damage caused by the exceeded current. 
     If the portable electronic device  10  is connected to the power supply  20  supplying insufficient power watts, for example, when the portable electronic device  10  needs more than 65 watts power, but the connected power supply  20  can only supplies 65 watts power, the power management module  12  performs the power management to reduce the consume power of the individual unit in the portable electronic device  10  so the total consume power of the portable electronic device  10  does not exceed 65 watts. Therefore, the portable electronic device  10  and the power supply  20  are prevented from damages. 
     Please refer to  FIG. 3A-3B .  FIG. 3A-3B  is a flow chart of a power management according to the invention. 
     Step  301 : obtaining a value of the voltage signal. 
     The power management module  12  obtains the value of the voltage signal. The voltage signal is generated from the power supply  20 , the sensing element  13  to the detecting module  11 , which is obtained in step  202 . The power management module  12  stores the value of the voltage signal in a register. 
     Step  302 : determining whether a first predetermined value preset for the portable electronic device is exceeded. 
     The power management module  12  compares the preset first predetermined value with the value of the voltage signal. The first predetermined value is the maximum watt allowed by the portable electronic device  10  and the power supply  20  under normal condition. When the value of voltage signal is above the preset first predetermined value, it indicates that the consume power watt of the portable electronic device  10  is larger than the allowed power watt of the power supply  20 . 
     Therefore, if the value of the voltage signal exceeds the first predetermined value, step  303  is performed: determining whether the CPU is operating at a low frequency. 
     The power management module  12  first checks whether the frequency of the CPU  14  is low. If the frequency of the CPU  14  is low, it is not necessary to lower the frequency of the CPU  14 , and the power management can be ended. 
     If the frequency of the CPU  14  is not low, step  304  is performed: reducing the frequency of the CPU. 
     If the CPU  14  is operating at a high frequency, the power management module  12  reduces the frequency of the CPU  14  to lower the consume power watt of the portable electronic device  10 . For example, the frequency of the CPU  14  is lowered from 2 GHz to 1 GHz. 
     Moreover, the power management module  12  also decides the method of reducing the frequency of the CPU  14 . For example, the frequency of the CPU  14  can be reduced straight down to the allowed value; or in order to avoid the portable electronic device  10  becomes unstable, the power management module  12  can also reduce the frequency of the CPU  14  to the allowed value gradually. Alternatively, the charging process can be stopped first, then the frequency of the CPU  14  is reduced; or the charging process is gradually stopped, and then the frequency of the CPU  14  is gradually reduced. The above mentioned four methods can be selected based on the requirement or utilized according to the stability of the portable electronic device  10 , and the invention can also utilize other method. 
     If the value of the voltage signal does not exceed the first predetermined value, step  305  is performed: determining whether the value of the voltage signal is below a second predetermined value preset for the portable electronic device  10 . 
     The power management module  12  determines whether the value of the voltage signal is below a second predetermined value. The second predetermined value is the minimum consume watt of the portable electronic device  10  under the normal operation. 
     If the value of the voltage signal is not lower than a second predetermined value, step  306  is performed: maintaining the frequency of the CPU  14 . 
     In step  305 , the power signal supplied by the power supply  20  is determined as in the allowed operation range of the portable electronic device  10 , so the frequency of the CPU  14  is maintained and the power management is ended. 
     If the value of the voltage signal is lower than the second predetermined value, step  307  is performed: repeating step  305 . 
     At this time, the power management module  12  first repeats step  305 , and then again determines whether the value of the voltage signal is lower than the second predetermined value preset for the portable electronic device  10 . Meanwhile, the timer  15  is utilizing for recoding the number of the repeating check to obtain a temporary value. 
     Next, step  308 : determining whether the result of step  305  is positive and the number of the repeating check has reached to a predetermined number. 
     In step  308 , the power management module  12  repeatedly determines whether the value of the voltage signal is lower than the second predetermined value preset for the portable electronic device  10  and determines whether the number of repeating check has reached to a predetermined number. For example, if the power management module  12  has checked the value of the voltage signal three times and the values of the voltage signal are all lower than the second predetermined value, it indicates the check result of the power management module  12  is correct. However, the predetermined number can be any other number not just three times. Therefore, it can prevent the mistake caused by the power management module  12 . 
     If the predetermined number has not been reached, it might because the power management module  12  made a mistake. Therefore, step  309  is performed: maintaining the frequency of the CPU  14  and ending the power management. Since step  309  is similar with step  306 , there will be no more description. 
     If the predetermined number has been reached, step  310  is performed: determining whether the CPU  14  is operating at a high frequency. 
     If the value of the voltage signal is lower than the second predetermined value, it indicates the power supplied by the power supply  20  has enough watts to satisfy the portable electronic device  10 . Therefore, the power management module  12  checks the frequency of the CPU  14  first. 
     If the CPU  14  is not operating at a high frequency, step  311  is performed: increasing the frequency of the CPU. 
     The power management module  12  increases the frequency of the CPU  14  to obtain the best performance of the portable electronic device  10 . 
     However, the power management module  12  can also decide the method for increasing the frequency of the CPU  14 . For example, the frequency of the CPU  14  can be directly increased to an allowed value; or in order to prevent the portable electronic device  10  from being unstable, the power management module  12  can also gradually increases the frequency of the CPU  14  to the allowed value. On the other hand, the frequency of the CPU  14  can be increased first, then the charging current is released; or the frequency of the CPU  14  can be gradually increased, then the charging current is also gradually released. The above mentioned four methods can be selected based on the requirement or the stability of the portable electronic device  10 , and other design can also be applied. 
     Then, step  312  is performed: clearing the temporary value. 
     The power management module  12  clears the temporary value of the repeating check to avoid the power management module  12  from performing the determining step again. 
     If the CPU  14  is operating at a high frequency, step  312  is performed to end the power management. However, if the watts of the supplying power is not enough and the frequency of the CPU  14  is increased, it will cause the portable electronic device  10  or the power supply  20  being damaged. Therefore, the preferred embodiment of the invention performs step  307  and step  308  to repeat the check, and then performs step  309  and step  310  to increase the frequency of the CPU  14 . 
     Finally, it returns back to step  301  to wait for next voltage signal input. 
     Moreover, the method of detecting the power signal of the invention can be performed in different step sequence as long as the purpose of the invention can be achieved. 
     With the above-mentioned system and method of the invention, when the portable electronic device  10  is connected to the power supply  20  supplying inefficient power watts, the power management is performed immediately to prevent the portable electronic device  10  or the power supply  20  from being overloaded or overheated causing damage. Furthermore, comparing with the prior art, the power signal detecting system  1  can lower the manufacturing cost. 
     Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.

Technology Category: 3