Abstract:
A power supply and data signal transmission method used in an induction type power supply system consisting of a power supply module and a power-receiving module for transmission of electrical energy and data signal is disclosed. The microprocessor of the power supply module scans the resonant point of the power supply coil to send a segment of energy for recognition of a feedback signal from the power-receiving module and then starts providing power supply after receipt of the feedback signal, and then runs further signal modulation, transmission, data decoding and other follow-up steps, achieving transmission of electrical energy and data signal wirelessly.

Description:
This application claims the priority benefit of Taiwan Patent application number 099113132 filed on Apr. 26, 2010. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to power supply systems and more particularly, to a power supplying and data transmitting method used in an induction type power supply system consisting of a power supply module and a power-receiving module for transmission of electrical energy and data signal. 
     2. Description of the Related Art 
     With the coming of digital era, many digitalized electronic products, such as digital camera, cellular telephone, music player (MP3, MP4) and etc., have been continuously developed and have appeared on the market. These modern digital electronic products commonly have light, thin, short and small characteristics. For high mobility, power supply is an important factor. A mobile digital electronic product generally uses a rechargeable battery to provide the necessary working voltage. When power low, the rechargeable battery can be recharged. For charging the rechargeable battery of a digital electronic product, a battery charger shall be used. However, it is not economic to purchase a respective battery charger when buying a new mobile electronic product. 
     Further, when using a battery charger to charge the rechargeable battery of a mobile electronic product, it is necessary to connect the connection interface of the battery charger to an electric outlet and then insert the power output plug of the battery charger to the power jack of the mobile electronic product. After charging, the user needs to remove the battery charger from the mobile electronic product. When wishing to charge the rechargeable battery of a mobile electronic product, the user must carry the mobile electronic product to a place where there is an electric outlet. When one goes out and there is no any electric outlet available, the user will be unable to charge the rechargeable battery of his (her) mobile electronic product. 
     Further, except of charging the battery, an electronic device may have to make certain function settings, to edit data, or to transmit data. Some electronic devices allow the use make setting and to edit and transmit data. However, some other electronic devices (such as, MP3, MP4, digital camera, electronic watch, portable game machine, wireless game grip, remote controller, and etc.) do not allow direct setting, data editing or data transmission. In this case, an external electronic device (computer, PDA) must be used to achieve setting, data editing or data transmission. Further, an electronic device cannot be operated to transmit data during battery charging. 
     Taiwan Patent Publication No. 201004086 discloses a power supply system, entitled “Induction type power supply system with battery scan function”, filed on Feb. 20, 2009 under application serial number 98105373, and issued on Jan. 16, 2010. This invention teaches the use of a load resistor for a signal modulation in an induction type power supply system to feed back signal from the secondary coil to the primary coil. However, this method still has drawbacks as follows: 
     1. The resistor type modulator consumes much power during signal modulation. The dynamic range of the modulation is determined subject to the value of the resistance at the load. Because the signal analysis ability of the primary coil in the power supply system is reduced subject to increasing of the distance of the secondary coil, the modulation dynamic range must be enhanced for data analysis, i.e., the resistance value must be reduced to amplify load effect during modulation. However, this method has a limitation. When the resistance at the load is close to a short-circuit status, no further adjustment is allowed. 
     2. During modulation, the positive pole of the power supply at the power-receiving end approaches the ground terminal. At this time, a surge goes through the rectifier and the voltage stabilizer in the loop, causing a sudden rise of temperature that may damage circuit components. 
     3. Due to the limitation of electrical characteristics, the resistor load must be installed posterior to the rectifier with a filter capacitor bridged over the ends. This voltage stabilizing effect slows down signal modulation reaction speed. In consequence, a relatively higher carrier frequency is necessary for signal analysis. 
     4. The transmission of signal is a one-way transmission to transmit the feedback signal from the secondary coil to the primary coil, i.e., the method does not allow transmission of a signal from the primary coil to the secondary coil. 
     Therefore, it is desirable to a power supplying and data transmitting method for induction type power supply system that eliminates the aforesaid problems. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a power supplying and data transmitting method, which is practical for transmission of electrical energy and data signal wirelessly. 
     To achieve this and other objects of the present invention, a power supplying and data transmitting method is used in an induction type power supply system consisting of a power supply module and a power-receiving module. The power supply module comprises a power supply microprocessor. The power supply microprocessor has electrically connected thereto a power supply driver unit, a power supply signal analysis unit, a voltage detector, a display unit, a power supply information management unit and a power circuit. The power supply driver unit comprises a half-/full-bridge driver electrically connected to the power supply microprocessor and two MOSFET arrays that are respectively connected to a resonant circuit. The resonant circuit has connected thereto a power supply coil that is adapted for transmitting electric energy and data signal. The power-receiving module comprises a power-receiving microprocessor that has electrically connected thereto a power-receiving unit, a signal processing unit, a power-receiving information management unit. The power-receiving unit comprises a voltage detection circuit, a charging management circuit, a current-detection protection system and a circuit breaker respectively connected to a voltage stabilizing circuit. The charging management circuit and the circuit breaker are respectively connected to a storage battery. The voltage detection circuit and the circuit breaker are respectively connected to a rectifier and filter circuit. The rectifier and filter circuit is connected to a resonant circuit. The resonant circuit is connected to a power-receiving coil, a carrier amplitude modulation circuit of a signal processing unit and a demodulation detection circuit of a power-receiving signal analysis circuit of the signal processing unit. Thus, power supply and data signal can be transmitted between the power supply module and the power-receiving module wirelessly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a circuit block diagram of a power supply module in accordance with the present invention. 
         FIG. 2  is a circuit block diagram of a power-receiving module in accordance with the present invention. 
         FIG. 3  is a simple circuit diagram of a part of the induction type power supply system in accordance with the present invention. 
         FIG. 4  is an operation flow chart of the present invention (I). 
         FIG. 5  is an operation flow chart of the present invention (II). 
         FIG. 6  is an operation flow chart of the present invention (III). 
         FIG. 7  is an operation flow chart of the present invention (IV). 
         FIG. 8  is a schematic drawing showing signal frequency modulation according to the present invention. 
         FIG. 9A  is a schematic drawing showing switching of signal modulation between full-bridge and half-bridge according to the present invention. 
         FIG. 9B  is a schematic drawing showing frequency conversion of signal modulation according to the present invention. 
         FIG. 9C  is a schematic drawing showing resonance feedback during signal modulation according to the present invention. 
         FIG. 9D  is a schematic drawing showing a data signal decoding process according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-7 , an induction type power supply system is shown comprising a power supply module  1  and a power-receiving module  2 . 
     The power supply module  1  comprises a power supply microprocessor  11  having installed therein an operation/control related software program. The power supply microprocessor  11  has electrically connected thereto a power supply driver unit  12 , a power supply signal analysis unit  13 , a voltage detector  14 , a display unit  15 , a power supply information management unit  16  and a power circuit  17 . The power supply driver unit  12  comprises a half-/full-bridge driver  121  electrically connected to the power supply microprocessor  11  and two MOSFET arrays  122 ; 123  that are respectively connected to a resonant circuit  18 . The half-/full-bridge driver  121  of the power supply driver unit  12  and the two MOSFET arrays  122 ; 123  are respectively connected to the power circuit  17 . The power supply signal analysis circuit  13  is electrically connected to the power supply microprocessor  11  and a demodulation detection circuit  132  through a comparator circuit  131 . Further, the demodulation detection circuit  132  is connected to the resonant circuit  18 . The power supply information management unit  16  has connected thereto a power supply input interface  161  and a transmission interface  162 . The transmission interface  162  is connected to a power connector  1621  and a power supply transmission information source  1622 . The power supply input interface  161  is connected to the power circuit  17  that is connected to a power source  171 . Further, the resonant circuit  18  has connected thereto a power supply coil  181  that is adapted for transmitting electric energy and data signal. 
     The power-receiving module  2  comprises a power-receiving microprocessor  21  having installed therein an operation/control related software program. The power-receiving microprocessor  21  has electrically connected thereto a power-receiving unit  22 , a signal processing unit  23  and a power-receiving information management unit  24 . The power-receiving unit  22  comprises a voltage detection circuit  221 , a charging management circuit  222 , a current-detection protection system  223  and a circuit breaker  224  respectively connected to a voltage stabilizing circuit  225 . The charging management circuit  222  and the circuit breaker  224  are respectively connected to a storage battery  226 . The voltage detection circuit  221  and the current-detection protection system  223  are respectively connected to the storage battery  226 . The voltage detection circuit  221  and the circuit breaker  224  are respectively connected to a rectifier and filter circuit  227 . The rectifier and filter circuit  227  is connected to a resonant circuit  25 . The resonant circuit  25  is connected to a power-receiving coil  251 , a carrier amplitude modulation circuit  231  of a signal processing unit  23  and a demodulation detection circuit  2321  of a power-receiving signal analysis circuit  232  of the signal processing unit  23 . The demodulation detection circuit  2321  is connected to a comparator circuit  2322  that is connected to the power-receiving microprocessor  21 . The power-receiving information management unit  24  is connected to a received power output device  26 . The received power output device  26  comprises a transmission interface  261  and an information source  262 . The transmission interface  261  and the information source  262  are connected to the power-receiving information management unit  24  that has connected thereto a power-receiving input system  241 . The transmission interface  261  is connected to the power-receiving terminal  2611  of the transmission interface  261  and the current-detection protection system  223 . 
     The power supply and data signal transmission method runs subject to the following steps:
         ( 300 ) The built-in software program of the power supply microprocessor  11  initializes a data encoder and a data decoder and defines a pulse length and then enters a standby mode, and then it proceeds to step ( 301 ) after a predetermined time interval;   ( 301 ) The built-in software program of the power supply microprocessor  11  automatically converts the frequency and scans resonant frequency f 1 , modulated frequency f 2  and charging frequency f 3 , and then sends a segment of charging frequency f 3  to the power supply driver unit  12 , causing the power supply driver unit  12  to drive the power supply coil  181  of the resonant circuit  18  in producing an electromagnetic wave signal;   ( 302 ) The power supply signal analysis circuit  13  analyzes the signal from the power supply coil  181  and determines whether or not the signal is a feedback signal from the power-receiving module  2 , and then proceeds to step ( 303 ) when positive, or returns to step ( 301 ) when negative;   ( 303 ) The power supply microprocessor  11  continuously sends charging frequency f 3  to the power supply driver unit  12 , causing it to drive the power supply coil  181  of the resonant circuit  18  in providing an electromagnetic wave signal to the power-receiving module  2 ;   ( 304 ) The power supply microprocessor  11  detects the power supply information management unit  16 , determining whether or not there is a data to be transmitted, and then it proceeds to step ( 306 ) when positive, or step ( 305 ) when negative;   ( 305 ) The power supply microprocessor  11  detects whether or not the power supply signal analysis circuit  13  receives a signal, and then it proceeds to step ( 316 ) when position, or returns to step ( 303 ) when negative;   ( 306 ) The power supply microprocessor  11  runs a data transmission program and modulates the signal, and then sends out a start signal;   ( 307 ) The power supply microprocessor  11  starts a counter to count the length of the defined start signal;   ( 308 ) The power supply microprocessor  11  outputs the modulated start signal;   ( 309 ) The power supply microprocessor  11  determines the signal in the register to be “1” or “0”, and then runs to step ( 310 ) when the signal is “1”, or step ( 312 ) when the signal is “0”;   ( 310 ) The power supply microprocessor  11  outputs the modulated signal “1”;   ( 311 ) The power supply microprocessor  11  starts the counter to count the length of the signal “1”, and then demodulates the modulated signal after counting, and then proceeds to step ( 314 );   ( 312 ) The power supply microprocessor  11  outputs the modulated signal “0”;   ( 313 ) The power supply microprocessor  11  starts the counter to count the length of the signal “0”, and then demodulates the modulated signal after counting;   ( 314 ) The power supply microprocessor  11  determines whether or not transmission of all the bits in the register has been done, and then turns off the data transmission program and proceeds to step ( 330 ) when positive, or proceeds to step ( 315 ) when negative;   ( 315 ) Send the next bit of the transmitting data in the register to the power supply microprocessor  11 , and then returns to step ( 309 );   ( 316 ) The power supply microprocessor  11  executes data decode program, detecting modulation of the signal;   ( 317 ) The power supply microprocessor  11  counts the pulse length of the received modulated signal;   ( 318 ) The power supply microprocessor  11  judges whether or not the start signal had been received, and then proceeds to step ( 319 ) when positive, or step ( 322 ) when negative;   ( 319 ) The power supply microprocessor  11  judges whether or not the pulse length is within the range of the start signal, and then proceeds to step ( 320 ) when positive, or step ( 321 ) when negative;   ( 320 ) The start signal is recognized, and the power supply microprocessor  11  starts to store the received bits, and then returns to step ( 316 );   ( 321 ) The start signal fails, the power supply microprocessor  11  ends the software program directly, and then proceeds to step ( 330 );   ( 322 ) The power supply microprocessor  11  judges whether or not the pulse length is within the range of the logic [1] signal, and then proceeds to step ( 323 ) when positive, or step ( 324 ) when negative;   ( 323 ) The power supply microprocessor  11  judges the bit of logic [1] has been received and then stores the bit in the internal data register, and then proceeds to step ( 327 );   ( 324 ) The power supply microprocessor  11  judges whether or not the pulse length is within the range of the logic [0] signal, and then proceeds to step ( 326 ) when positive, or step ( 325 ) when negative;   ( 325 ) Noises are in presence, and the power supply microprocessor  11  clears the incomplete bit data, and then proceeds to step ( 330 );   ( 326 ) The power supply microprocessor  11  judges the bit of logic [0] has been received and then stores the bit in the internal data register;   ( 327 ) The data register stores the received data.   ( 328 ) The power supply microprocessor  11  judges whether or not receipt of the assigned bits has been done, and then proceeds to step ( 329 ) when positive, or returns to step ( 316 ) when negative;   ( 329 ) The power supply microprocessor  11  outputs the data to the external electronic apparatus;   ( 330 ) The power supply microprocessor  11  recognizes the content of the data, and then sends the data to the power supply information management unit  16  or the display unit  15  subject to the request of the software program;   ( 331 ) The power supply microprocessor  11  utilizes a power supply control program to monitor charging status, and returns to step ( 301 ) when the power-receiving module  2  is beyond the induction range.       

     In the aforesaid power supply module  1 , the power circuit  17  can receive power from the external power source  171  that can be city power supply, or the power supply of an external electronic apparatus. The external electronic apparatus can be a power supply component of a computer, power supply device or storage battery. Further, the two MOSFET arrays  122 ; 123  of the power supply driver unit  12  are adapted to switch between a full-bridge frequency and a half-bridge frequency. During the power supply mode, the two MOSFET arrays  122 ; 123  drive the power supply coil  181  to oscillate, thereby emitting electrical energy. Further, the power supply microprocessor  11  automatically converts the frequency and scans resonant frequency f 1 , modulated frequency f 2  and charging frequency f 3  of the power supply coil  181  of the resonant circuit  18  within a predetermined length of time. The predetermined length of time can be 1 second, 2 seconds, or a relatively longer time. Within this predetermined length of time, no frequency is to be sent out, and only a length of 1/100 seconds of charging frequency f 3  is sent out to detect whether or not the power-receiving module  2  is within the induction range. Thus, the operating time of the power supply module  1  is minimized, saving the energy. 
     As stated above, the power supply signal analysis circuit  13  consists of the comparator circuit  131  and the demodulation detection circuit  132 . The data signal received by the power supply coil  181  is sent to the comparator circuit  131  for analog/digital conversion, enabling the converted digital signal to be transmitted to the power supply microprocessor  11  so that the power supply microprocessor  11  can display the data on the display unit  15 . The power supply input interface  161  of the power supply information management unit  16  can be any data input device, such as keyboard, mouse, remote controller or cursor control device. Further, the transmission interface  162  of the power supply information management unit  16  can be a USB interface, eSATA interface or HDMI interface for data signal transmission. 
     Further, the transmission interface  261  of the received power output device  26  can be a USB interface, eSATA interface or HDMI interface for data signal transmission. The information source  262  of the received power output device  26  can be a computer or PDA that is capable of making, editing, setting and processing data signal. 
     Further, the power-receiving terminal  2611  of the transmission interface  261  of the received power output device  26  is adapted to charge the battery of an external electronic apparatus wirelessly. The external electronic apparatus can be a mobile telephone, MP3, MP4, MP5, digital camera, electronic watch, portable game machine, wireless game grip or remote controller that is to be charged and that can edit, process and transmit data signal. 
     Referring to  FIGS. 8 ,  9 A,  9 B and  9 C and  FIGS. 1-3  again, the power supply module  1  switches the MOSFET arrays  122 ; 123  between the half-bridge mode and the full-bridge mode via the half-/full-bridge driver  121  of the power supply driver unit  12 . When switched to the half-bridge mode, it is the normal operation status. When switched to the full-bridge mode, the amplitude is multiplied, and the signal is modulated. When adjusted to the original frequency or switched back to the half-bridge mode, it is returned to the original amplitude. Through the power supply coil  181  of the resonant circuit  18 , the modulated signal is transmitted to the power-receiving coil  251  of the power-receiving module  2 . Further, increasing the amplitude of the modulation relatively increases the amplitude of the signal received by the power-receiving coil  251 . On the contrary, reducing the amplitude of the modulation relatively reduces the amplitude of the signal received by the power-receiving coil  251 . 
     Further, the carrier amplitude modulation circuit  231  of the signal processing unit  23  that is connected to one end of the power-receiving coil  251  comprises an inductor  2311 , a diode  2312  and a switch  2313 . The switch  2313  is a MOSFET device for data signal modulation control. When switching the switch  2313  to the close-circuit position, the inductor  2311  will cause floating of the resonant characteristic of the power-receiving coil  251 . Thus, a dynamic modulation is produced within a short time subject to lowering of the signal at the ends of the power-receiving coil  251 . The signal will be fed back to the power supply coil  181  of the power supply module  1 . This is to say that when the resonant characteristic of the power-receiving coil  251  is floating the power supply coil  181  of the power supply module  1  loses its resonance reaction temporarily, resulting in increased amplitude. The power supply coil  181  and the power-receiving coil  251  will resume to the status before signal modulation for transmission of electrical energy only after modulation of the data signal. 
     The aforesaid signal modulation can be achieved by means of full-/half-bridge switching, frequency conversion or the application of an inductor to cause floating of coil resonance characteristic. The power supply module  1  and the power-receiving module  2  can modulate data signal by means of one of the aforesaid three techniques. Preferably, the power supply module  1  uses the technique of full-/half-bridge switching or frequency conversion to modulate data signal; the power-receiving module  2  uses the inductor  2311  to cause floating of the resonant characteristic of the power-receiving coil  251 . These techniques are simply for increasing the signal amplitude for data transmission, but not intended for use as limitations. 
     After change of the amplitude of the power supply coil  181  or power-receiving coil  251 , the data signal is converted into a data code by the demodulation detection circuit  132  or  2321  and a decode software. The demodulation detection circuit  132  or  2321  consists of a plurality of capacitors, resistors and filters. The data signal obtained through the demodulation detection circuit  132  or  2321  is an analog signal that must be converted into a digital signal by the comparator circuit  131  or  2322 . This digital signal is then transmitted to the power supply microprocessor  11  or power-receiving microprocessor  21  for analysis by the decoder software built therein. Because the pulse width of the signal will bias after transmission wirelessly, it is necessary to correct the bias by means of a decoder software setting, converting the bias into accurate digital signal logic “0” or logic “1”, or judging the signal to be an unreadable noise. 
     Referring to  FIG. 9D  and  FIGS. 1-3  again, if the level of the signal is higher than the reference voltage of the comparator during operation of the power supply module  1  or power-receiving module  2 , the signal is judged to be a modulated signal (HI); if the level of the signal is lower than the reference voltage of the comparator during operation of the power supply module  1  or power-receiving module  2 , the signal is judged to be an unmodulated signal (LOW). When no data is in transmission, the demodulation detection circuit  132  or  2321  is kept on the status of LOW. On the contrary, when a data signal is modulated, the demodulation detection circuit  132  or  2321  scans the level of the signal to be higher than the reference voltage of the comparator, i.e., on the status of HI. At this time, the signal is transmitted to the power supply microprocessor  11  or power-receiving microprocessor  21  for decoding by the respective decoder software. 
     By means of the aforesaid data transmission operation between the power supply module  1  and the power-receiving module  2 , data signal for setting, editing or processing control can be transmitted between the power supply module  1  and the power-receiving module  2  as the power-receiving module  2  charges the battery of an external electronic device. 
     As stated above, the invention provides a power supplying and data transmitting method for induction type power supply system, which enables a power supply microprocessor  11  of a power supply module  1  to receive electrical energy from a power circuit  17  or data signal from a power supply information management unit  16  and to send the electrical energy or data signal to a power supply driver unit  12  for transmission to a power-receiving coil  251  of a resonant circuit  25  of a power-receiving module  2  through a power supply coil  181  of a resonant circuit  18 . Upon receipt of the electrical energy/data signal from the power supply coil  181 , the resonant circuit  25  of a power-receiving module  2  transmits the electrical power/data signal to a power-receiving microprocessor  21  through a power-receiving unit  22  and a signal processing unit  23 , enabling the electrical energy/data signal to be transmitted to an external electronic apparatus through a received power output device  26 . By means of a power supply input interface  161  of the power supply information management unit  16 , setting, editing and data signal processing and transmission command signals are inputted into the power supply module  1  for transmission to the power-receiving coil  251  of the power-receiving module  2 , enabling the power-receiving module  2  to control setting, operation or editing of the external electronic apparatus. Thus, the invention achieves battery charging and data transmission in a wireless manner. 
     In conclusion, the invention provides a power supplying and data transmitting method for induction type power supply system, which has the following advantages and features: 
     1. By means of the power supply information management unit  16  of a power supply module  1 , input data signal is transmitted to the power supply microprocessor  11  for transmission to the power-receiving coil  251  of the resonant circuit  25  of the power-receiving module  2  through the power supply coil  181  of the resonant circuit  18  subject to the driving control of the power supply driver unit  12 , avoiding signal power loss or dynamic range limiting of the modulation, and assuring data signal transmission stability. 
     2. During transmission of electrical energy/data signal between the power supply module  1  and the power-receiving module  2 , sudden surge is prohibited, avoiding component damage. 
     3. During transmission of electrical energy between the power supply module  1  and the power-receiving module  2 , data signal transmission can be simultaneously and rapidly performed without causing interference or the use of a high carrier frequency. 
     4. Transmission of electrical energy and data signal between the power supply module  1  and the power-receiving module  2  is performed through the power supply coil  181  of the resonant circuit  18  and the power-receiving coil  251  of the resonant circuit  25 , assuring high reliability. 
     A prototype of power supplying and data transmitting method for induction type power supply system has been constructed with the features of  FIGS. 1-9D . The power supplying and data transmitting method for use in an induction type power supply system works smoothly to provide all of the features disclosed earlier. 
     Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.