Abstract:
A breaker connected between a power source end of an electric device and a power source comprises a power retriever for setting a first reference voltage; the first reference voltage being corresponding to a limiting value; a comparator for comparing a first reference voltage and a second reference voltage value; the second reference voltage value being corresponding to a power used in the electric device; a timer; when the second reference voltage value being smaller than the first reference voltage; the timer determining whether a counting time period is over a breaking time; and a switch; if the time period is over the breaking time, the switch will turn off a connection between a power source end of the electric device and the power source.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to breakers, and particularly to a breaker which can reduce the power consumption as an electric device is in standby state, while the user is unnecessary to withdraw a plug. Furthermore the short circuit is avoided. 
       BACKGROUND OF THE INVENTION 
       [0002]    With the improvement of electronic technologies, more and more electric devices are used in daily life, such as TVs, microwave ovens, air conditioners, etc. All these are used almost in every home. However, generally, when these devices are not used, the plugs of these devices are retained in the receptacle. However, this will induce power consumption. Statistically, the power consumption for TV in standby is about 0.1 to 4.2 watts, for microwave ovens, is about 0.1 to 4.2 watts, for stereos, is about 0.04 to 14.9 watts. In one year, 300 kilowatt-hours are needs for one home. 
         [0003]    Although governments propagate to withdraw plugs as the electric devices are not used, the effect is not good, because it is very inconvenient, even the plug is easily damaged or for a long time, the plug can not be well engaged with the receptacle. 
         [0004]    In summary, for saving power, and avoiding the plugs and receptacles are damaged, a novel device which can isolate electric power in standby state is necessary. 
       SUMMARY OF THE INVENTION 
       [0005]    Accordingly, the primary object of the present invention is to provide a breaker which can reduce the power consumption as an electric device is in standby state, while the user is unnecessary to withdraw a plug. Furthermore the short circuit is avoided. 
         [0006]    To achieve above objects, the present invention provides a breaker connected between a power source end of an electric device and a power source, comprises a power retriever for setting a first reference voltage; the first reference voltage being corresponding to a limiting value; a comparator for comparing a first reference voltage and a second reference voltage value; the second reference voltage value being corresponding to a power used of the electric device; a timer; when the second reference voltage value being smaller than the first reference voltage; the timer determining whether a counting time period is over a breaking time; and a switch; if the time period is over the breaking time, the switch will turn off a connection between a power source end of the electric device and the power source. 
         [0007]    The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  shows the circuit diagram of the first embodiment of the breaker of the present invention. 
           [0009]      FIG. 2  is a schematic view about the second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0010]    In order that those skilled in the art can further understand the present invention, a description will be provided in the following in details. However, these descriptions and the appended drawings are only used to cause those skilled in the art to understand the objects, features, and characteristics of the present invention, but not to be used to confine the scope and spirit of the present invention defined in the appended claims. 
         [0011]    Referring to  FIG. 1 , the breaker  1  of the present invention is illustrated. The breaker  1  of the present invention is suitable for any electronic device. The breaker  1  is connected between a power source and a power source end of an electric device. The breaker  1  is installed in an interior of an electric device. The power source end connected to the breaker  1  is connected to a control circuit in the electric device. The control circuit receives a signal to actuate or turn off the electric device. The electric device receives power through the breaker  1 . The breaker  1  includes an input end  101 , an output end  103 , a fuse  105 , a bridge full wave rectifier  107 , a Zener diode  109 , a filter capacitor  111 , a timer  113 , a transformer  115 , a power retriever  117 , comparator  119 , a transistor  121 , and a switch  123 . The switch  123  includes a button  125  and a relay  127 . The timer  113  includes a power source end  129 , reset end  131 , and an output end  103 . The connections of all the elements are illustrated in  FIG. 1 . 
         [0012]    A plug of the electric device is connected to a receptacle for having an alternative current of 110 Volts. The alternative current is inputted from the input end  101 . After inputting the alternative current, the current flows through the fuse  105  for preventing from over-current so as to protect the circuit. 
         [0013]    When the user desires to start the electric device, firstly, the user presses the button  125 , and then presses the switch of the electric device for actuating the control circuit in the electric device and thus the electric device starts. Then alternative current outputs from the output end  103  to the control circuit of the electric device for supplying electric power. Meanwhile, the current is transferred to the bridge full wave rectifier  107 . In this embodiment, the bridge full wave first input end  135 , a second input end  137 , a ground end  139  and an output end  141 . The bridge full wave rectifier  107  receives the alternative current of  110  volts through the first input end  135  and the second input end  137 . The alternative current is rectified through an internal diode. Then a direct current  102  of  12  volts is outputted from the output end  141  of the bridge full wave rectifier  107 . Thus, the bridge full wave rectifier  107  has the effect of converting the alternative current of 110 Volts to the direct current  102  of 12 Volts. 
         [0014]    The Zener diode  109  has the effect of stabilizing the voltage of the direct current  102  of 12 volts outputted from the bridge full wave rectifier  107 . After the current is filtered by the filter capacitor  111 , the direct current  102  flows to the power source end  129  as the current source of the timer  113  and also to the power source end of the comparator  119  as the power source of the comparator  119 . Thereby the direct current  102  also flows to the power retriever  117  and the emitter of the transistor  121 , wherein the transistor  121  is a PNP transistor. 
         [0015]    In this embodiment, the power retriever  117  includes a variable resistor (variator) and the comparator  119  may be an OP amplifier. The transformer  115  transfers the voltage to the electric device into a voltage suitable for the OP amplifier (operation amplifier). This voltage is as a second reference voltage value  106 . The variator of the power retriever  117  provides a first reference voltage  104  to the OP amplifier. The first reference voltage  104  is corresponding to a preset power limiting value which is changeable by adjusting the variator. In this embodiment, we assume that the standby power of this electric device is 3 Watts. The power of the electric device is 7 Watts. Thus, the first reference voltage  104  can be adjusted properly so that the corresponding power limiting value is 5 watts. The OP amplifier serves to compare the first reference voltage  104  with the second reference voltage value  106 . Because the electric device is now used, thus the power of the electric device is greater than the power limiting value. Thus, the second reference voltage value  106  will great than the first reference voltage  104 . The OP amplifier will output a high level reset signal  108  to the reset end  131  of the timer  113 . Then the timer  113  receives this high level reset signal  108 , it will reset the timer  113  continuously. 
         [0016]    Since the timer  113  is reset continuously, the time of the timer  113  is not greater than a preset power-off time in the timer  113 , for example, 10 minutes. The output end  133  of the timer  113  will output a lower level signal to the base of the transistor  121 . Then the transistor  121  will conduct. The current  110  will flow through the collector of the transistor  121  to the relay  127  of the switch  123  so as to conduct the relay  127 , even the button  125  is not pressed, it still retains the conduction of the interior of the breaker  1 . In summary, in use, the second reference voltage value  106  will be greater than the first reference voltage  104  continuously. The comparator  119  will output rest signals  108  continuously so that the timer  113  rests continuously. The counting time is not greater than the breaking time of the timer  113  and thus the breaker  1  will supply power continuously. 
         [0017]    When the user does not use this electric device, the user will press the switch of the electric device so as to turn off the electric device. The electric device will present a standby state. Then the alternative current  20  will output the current from the output end  103  and transfer the current to the bridge full wave rectifier  107 . Similarly, the bridge full wave rectifier  107  will rectify the alternative current of 110 volts into direct current  102 . The direct current  102  is stabilized by the second reference voltage value  106  and then is transferred to the timer  113 , the power retriever  117 , the comparator  119  and the emitter of the transistor  121 . 
         [0018]    When the OP amplifier compares the0 second reference voltage value  106  with the first reference voltage value  104 , because the electric device is in a standby state, the second reference voltage value  106  is smaller than the first reference voltage  104 . Then the OP amplifier will output a low level reset signal  108  to the reset end  131  of the timer  113 . Then the timer  113  will be actuated. 
         [0019]    When the time period of the timer  113  is greater than a preset breaking time in the timer  113 , for example, 10 minutes, the output end  133  of the timer  113  will output a high level signal to the base of the transistor  121 . The transistor  121  will turn off. Current can not flow to the relay  127  through the collector of the transistor  121 . Thus, the relay  127  does not conduct. The breaker  1  is turned off. Thus no power is consumed as the transformer  115  is in standby state. The electric device is turned off completely. 
         [0020]    If after the electric device is turned off, it is actuated in a preset time, since the output end  133  of the timer  113  is still in low level output state, after the relay  127  conducts, the electric device can work continuously. 
         [0021]    If the user desires to open the electric device, he (or she) presses the button  125  so that the electric device is in the standby state. If it is not actuated in the turning off time period, the time period of the timer  113  will be greater than the preset breaking time. The breaker  1  will turn off. 
         [0022]    In above mentioned embodiment, the bridge full wave rectifier  107  is one of the bridge full wave rectifier with a part No. RS405 produced by LerSan Wireless Co. Ltd, or a prior art bridge full wave rectifier with four diodes. The timer  113  is one of a 14 bits binary ripple counter with part number 4060 or 4020 produced by Fairchild Semiconductor Co., or a micro central processing unit, or a simple chip, or other integrated circuit with a counter or a timer. 
         [0023]    In other embodiment, the breaker  1  may be used singly. The plug of the electric device is firstly inserted to the output end  103  of the breaker  1  and then the input end  101  of the breaker  1  is connected to the plug. The power source end of the electric device is connected to a power source through the breaker. 
         [0024]    In other embodiment, the switch  125  is positioned at a remote controller of an electric device. When the button  125  is pressed, the signals from the button  125  will control the breaker  1  wirelessly. The way for transmitting signals is not confined in the present invention, for example, by supersonic waves, infrared rays, or others. The relay  127  may be a silicon controlled rectifier, SCR). 
         [0025]    Referring to  FIG. 2 , the second embodiment of the present invention is illustrated. In this embodiment, one breaker  2  is installed to a wire box  23  of a receptacle  21  of an alternative current  20 . The receptacle  21  is embedded into a wall. The alternative current  20  from the power company will transfer to the breaker  2  and then to the receptacle  21 . When it is desired to use the electric device, it is only necessary to insert the plug into the receptacle  21 . Thus, the electric device using the receptacle  21  saves power through the breaker  2 . The button  125  of the switch (not shown) is installed in a receptacle panel  27  of the receptacle  21 . Thus the user can use this device conveniently. Of course, those skilled in the art can install a breaker (as the breaker  1  or breaker  2 ) to a power supply of an electric device or is connected thereto internally or externally. 
         [0026]    Other above mentioned two embodiments, in the present invention, the comparator and timer of the present invention can be realized mechanically. It can be a whole mechanical structure or only a part thereof is mechanic. 
         [0027]    The present invention is thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.