Abstract:
An apparatus and method for converting audio signals to power supply signals that includes a step-up transformer, rectifier, and energy storage device on each channel, and uses information on one channel to control the output voltage sources.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present disclosure relates to the use of mobile computers and other electronic to charge and sequence power in their accessories. 
       BACKGROUND OF THE INVENTION 
       [0002]    Method for powering an accessory device using the audio output ports of devices like Walkman and computers have existed for some time. Though the audio output per channel from the said devices could be of the order of 30 mW to 55 mW per channel, use is limited to accessories that consumes less than about 10 mW considering losses in conversion to higher usable voltage from the 0.15-0.4V peak-to-peak at the audio output. 
         [0003]    The electronics industry still seeks a useful approach to audio signal conversion that is not limited to such small power needs. 
       SUMMARY OF THE INVENTION 
       [0004]    The present disclosure includes an apparatus and method by which the traditional limitations of audio signal conversion are overcome to allow such circuits to provide useful power. 
         [0005]    The method here aims to overcome this limitation by accumulating power over time and releasing the stored power in a controlled manner to sections that use higher power. 
         [0006]    Software running on the mobile computer device is a critical element of this invention. The software puts out an appropriate frequency audio signal at the output of the audio out of the device to keep the accessory powered or charged as needed in the background. 
         [0007]    Optionally, the system detects the presence of an accessory plugged in to prevent audio disturbance from the speaker in the absence of an accessory. 
         [0008]    Novel and inobvious aspects of the invention comprise a new approach to control of the audio signal to allow power storage and delivery. Other features and advantages of the present disclosure will be apparent to those of ordinary skill in the art upon reference to the following detailed description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    For a better understanding of the disclosure, and to show by way of example how the same may be carried into effect, reference is now made to the detailed description along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts. 
           [0010]      FIG. 1  shows a block diagram of one embodiment of the invention. 
           [0011]      FIG. 2A  provides a sample input of the left audio channel used to create maximum power with the invention. 
           [0012]      FIG. 2B  provides a sample input of the right audio channel used to control the output of the invention. 
           [0013]      FIG. 3  shows a detailed circuit diagram of one embodiment of the invention. 
           [0014]      FIG. 4  discloses a second embodiment of the invention, employing a different sequencing mechanism. 
           [0015]      FIG. 5  discloses a third embodiment of the invention using yet another sequencing mechanism. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    While the making and using of various embodiments of the present disclosure are discussed in detail below, it should be appreciated that the present disclosure provides many applicable inventive concepts, which can be embodied in a wide variety of specific contexts. The disclosure is primarily described and illustrated hereinafter in conjunction with various embodiments of the presently-described systems and methods. The specific embodiments discussed herein are, however, merely illustrative of specific ways to make and use the disclosure and do not limit the scope of the disclosure. 
         [0017]      FIG. 1  shows a block diagram of the preferred embodiment of the invention, which comprises the electrical components between the Mobile Computer  10  and the Accessory  150 . The whole circuit may be enclosed within an accessory, in that case  150  shows the main part of the accessory other than the power supply. 
         [0018]    The Headphone Connector  20  accepts signals from the Mobile Computer, conveyed by an audio out on Left Channel Wire  30  and Right Channel Wire  40 . 
         [0019]    Left and Right Channel Transformers  50   60  convert the audio signals. Typically these signals do not exceed 0.4V, so they are stepped up by a factor of 10 to 20 in current embodiments. 
         [0020]    The stepped up signals from the Left and Right Channel Transformers  50   60  then feed into Left and Right Channel Rectifiers  70   80 , respectively, which convert the magnified sinusoidal audio signal into an effective DC power source ranging from 3V to 5V, depending on the components employed in the circuit. 
         [0021]    The converted signals leave the Rectifiers  70   80  and feed into Power Storage Element  90  and Signal Storage Element  100 . In the current embodiment, capacitors serve as the Power Storage Element  90  and Signal Storage Element  100 , but in other applications considered, a battery might be employed for these elements. In many applications, Power Storage Element  90  is ideally a super capacitor with storage capacity with several magnitudes more storage than Signal Storage Element  100 . This difference allows the voltage on the Signal Storage Element  100  to change quickly, a desired trait necessary for fast signal change. In comparison, the Power Storage Element  90  has no need to change voltage quickly; its task in the circuit is to store as much power as practicable. 
         [0022]    In the current embodiment, the audio signal from the left channel is converted to power in Power Storage Element  90 , where it accumulates and becomes ready for use as a stable voltage source. However, the audio signal from the right channel becomes a control signal generated by Signal Storage Element  100 , which when energized, acts to release the converted and stored power. 
         [0023]    The right channel Power Storage Element  100  feeds into Voltage Comparator  110 . When the voltage on the Power Storage Element  100  exceeds a set level, the Comparator  110  triggers the Switch  120  to deliver higher power through connection  140  to the accessory  150 . 
         [0024]    As  FIG. 1  shows, in the embodiment shown, the user-supplied Accessory  150  always has use of the high voltage output of Power Storage Element  90  through Output Connection  130 . However, the signal generated through the right channel controls a second output source through Output Connection  140 . 
         [0025]      FIG. 2A . shows a sample wavelength Left Power Signal  200  created by the Mobile Computer  10  and sent to the left channel when instructed by software running on it. The waveform is designed to transmit signals with as much power output as possible to charge Storage Element  90 . 
         [0026]    Operating Signal  210  of  FIG. 2B  is a control signal, so it does not appear as continuous and unchanging, but is designed to cease and allow the control signal feeding the right channel Power Storage Element  100  to reduce to 0V output, or at least below the trigger voltage on the Comparator, and in this way, control the voltage supply to the Accessory  150 , which provides a controlled source to the high power consumption circuits of the Accessory  150  as needed. 
         [0027]    In this example embodiment, as shown in  FIG. 2B , software on the Mobile Computer  10  causes the Mobile Computer  10  to emit a Right Channel Operating Signal  205  along Right Channel Wire  40 , which is applied to the Right Channel Transformer  60 , which is typically in one of two states. It begins with a Charging Time  220 , a null output for an initial period of time, followed by an Energizing Time  210 . 
         [0028]    The Charging Time  220  begins as a null signal to allow the Left Channel Power Storage Element  90  to charge to an operating level. 
         [0029]    The Charging Time  220  signal is followed by an Energizing Time  210 , which charges the Right Channel Power Storage Element  100 , and subsequently causes a change of state in the Comparator  110  and Gate  120 , and power delivered to the load along Controlled Voltage Output  140 . The cycle repeats as directed by the software to allow the power storage elements time to charge and repeat a cycle in which an Accessory  150  can include a high power load. 
         [0030]    The minimum duration that the invention must receive from the Mobile Computer  10  on Left Channel Power Signal  200  depends on the size of the Power Storage Element  90  and the power requirement on Output  140 . The Right Channel Operating Signal  205  can be used to sequence power to Controlled Voltage Output  140  as needed provided the Power Storage Element  90  has been charged. The invention responds to the instructions to provided to it by the Mobile Computer  10  through the Right Channel Operating Signal  205 . 
         [0031]      FIG. 3  provides a schematic of one embodiment of the invention. Certain other elements not previously discussed are minor components designed to make the circuit more efficient and reliable, such as the Impedance-Matching Capacitors  51  and Overvoltage Protection Diode  91 . 
         [0032]    Also in the current embodiment, Left Channel Rectifier is a low leakage Schottky bridge rectifier for efficiency. The rectified DC voltage of this channel is used to charge the Power Storage Element  90 , a position currently held by a supercapacitor. Current limiting is done by the winding impedance of the Transformers  50   60 . Every knowledgeable electrical engineer is familiar with these and other similar design techniques and are not specific to this invention. 
         [0033]      FIG. 4  discloses another embodiment of the invention, similar to that of  FIG. 1 , except that the Signal Storage Element  100  on the right channel is not included. Both rectifiers feed into the Power Storage Element  90 , which allows faster charging of the storage device  90  and more power output as both audio output channels are used to charge the same capacitor. Voltage Comparator  110  now compares the Power Storage Element  90  to an internal reference, and triggers the Gate  120  on that attaining a certain voltage level. 
         [0034]      FIG. 5  discloses another embodiment of the invention, similar to the  FIG. 4 . embodiment, except it has two sequencing mechanisms. This is achieved by removing the Voltage Comparator  110  of  FIG. 4  and adding a Frequency Comparator  112  on left audio output channel and a Pulse-Width comparator  114  on the right channel. This allows the outputs  142  and  145  to be sequenced independently. To trigger output  142 , the frequency of the charging signal on the left channel is changed by the software running on Mobile Computer  10  to that frequency that causes the Frequency Comparator  112  to trigger Gate  120 . To trigger Output  145 , the pulse width on the Left Channel  30  is provided by the Mobile Computer  10  to that pulse width relation that causes the Pulse-Width Comparator  114  to trigger Gate  121 . 
         [0035]    Though the embodiments described herein include a computer control signal of some sort, the invention does not have to require software control. A simplified version of the embodiment without specific voltage control can easily be constructed to take the signals from the Mobile Computer  10 , rectify and store it, and just allow the Accessory  150  to draw what it needs for the user&#39;s purpose. 
         [0036]    It is asserted that any person with skill in the art can determine the electronic components required to build the circuits designed. For example, the Voltage Comparator  110  element could be a MOSFET with a minimum voltage requirement to turn on, and also act as the Gate  120 . More specialized circuitry can also be used. The time when the minimum voltage requirement is met is dependent on the Operating Signal  210  generated by the Mobile Computer  10 , and storage elements. 
         [0037]    All embodiments described herein are presented for purposes of illustration and explanation only. These descriptions of one embodiment are not intended to be limiting to the embodiments described. Those skilled in the relevant art will be able to create other embodiments based on this disclosure and the claims attached with this application. 
         [0038]    The user should recognize that the Mobile Device  10  will have software running that provides signals to operate the invention by generating appropriate inputs to each channel. 
         [0039]    A legend of referenced components in the drawings included in this system is as follows: 
         [0000]    
       
         
               
               
               
               
             
           
               
                   
               
             
             
               
                 10 
                 Mobile Computer 
                 120 
                 Gate 
               
               
                 20 
                 Headphone Connector 
                 121 
                 Gate 
               
               
                 30 
                 Left Channel Wire 
                 130 
                 Continuous Voltage Output 
               
               
                 40 
                 Right Channel Wire 
                 140 
                 Controlled Voltage Output 
               
               
                 50 
                 Left Channel Transformer 
                 142 
                 Frequency Voltage Output 
               
               
                 60 
                 Right Channel Transformer 
                 150 
                 Accessory (not part of 
               
               
                 70 
                 Left Channel Rectifier 
                   
                 the invention) 
               
               
                 80 
                 Right Channel Rectifier 
                 200 
                 Left Channel Power Signal 
               
               
                 90 
                 Power Storage Element 
                 205 
                 Right Channel Operating 
               
               
                 100 
                 Signal Storage Element 
                   
                 Signal 
               
               
                 110 
                 Comparator 
                 210 
                 Energizing Time 
               
               
                 112 
                 Frequency Comparator 
                 220 
                 Charging Time 
               
               
                 114 
                 Pulse-Width Comparator