Abstract:
An induction type power supply device includes a power supply base unit having a connection interface connectable, an oscillator circuit for producing an AC signal upon connection of the connection interface to an electric outlet, a driver circuit for amplifying the AC signal and a primary inductor for obtaining a resonant frequency and releasing the AC signal, and an attached induction device placed on the power supply base unit and having a secondary inductor for receiving the AC signal from the primary inductor by means of magnetic induction, a rectifier filter circuit for converting the AC signal into a DC power supply, a power management circuit for regulating the DC power supply subject to a predetermined voltage and current value and a connection device for the connection of an external mobile electronic apparatus and for outputting the regulated DC power supply from the power management circuit to the connected external mobile electronic apparatus.

Description:
[0001]    This application claims the priority benefit of Taiwan patent application number 097207329 filed on Apr. 28, 2008. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to power supply devices and more particularly an induction type power supply device, which comprises a power supply base unit connectable to an electric outlet to obtain an AC power supply, and an attached induction device placed on the power supply base unit for receiving the AC power supply from the power supply base unit by means of magnetic induction and converting the AC power supply into the desired DC power supply for output to an external mobile electronic apparatus being connected thereto. 
         [0004]    2. Description of the Related Art 
         [0005]    With the coming of digital era, many digitalized electronic products, such as digital camera, cellular telephone, music player (MP3) 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. 
         [0006]    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. 
         [0007]    The use of a conventional battery charger has the drawbacks as follows: 
         [0008]    1. When using many different mobile electronic products, one shall have to prepare many different battery chargers for charging the mobile electronic products separately. It costs a lot to prepare many different battery chargers. 
         [0009]    2. A conventional battery charger can be used to charge a mobile electronic product only where there is an electric outlet. When one goes out to a place where there is no any electric outlet and the power of the rechargeable battery of his(her) mobile electronic product is low, he(she) will be unable to charge the mobile electronic product in time. 
         [0010]    Therefore, it is desirable to find a way that eliminates the aforesaid problems. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide an induction type power supply device, which is practical for use to charge different mobile electronic products. It is another object of the present invention to provide an induction type power supply device, which is practical for use outdoors to charge different mobile electronic products with self-provided storage battery. 
         [0012]    To achieve these and other objects of the present invention, an induction type power supply device comprises a power supply base unit having a primary inductor, and an attached induction device having a secondary inductor. When placed the attached induction device on the power supply base unit after connection of the power supply base unit to an electric outlet, the attached induction device obtains an AC signal from the power supply base unit by means of magnetic induction and converts the AC signal into a DC signal for charging an external mobile electronic product. Further, different attached induction devices with different connection interfaces can be used with the power supply base unit to charge different mobile electronic products having different connection interfaces. 
         [0013]    In one embodiment of the present invention, the attached induction device has installed therein a charging module, which comprises a charging circuit and a rechargeable battery and connected in series between a rectifier filter circuit and a power management circuit. Normally, the rechargeable battery stores battery power. When the user goes out, the attached induction device can be used to charge a mobile electronic product when the power of the rechargeable battery of the mobile electronic product is low and when there is no any electric outlet available. 
         [0014]    In another embodiment of the present invention, the power supply base unit has installed therein a feedback circuit, a primary control circuit, and an oscillator circuit. The feedback circuit feeds back the voltage of the resonant circuit of the primary inductor to the primary control circuit for comparison with a predetermined reference voltage so that the primary control circuit outputs a control signal to the oscillator circuit to regulate the resonant frequency subject to the comparison result. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a circuit block diagram of an induction type power supply device in accordance with a first embodiment of the present invention. 
           [0016]      FIG. 2  is a circuit block diagram of an induction type power supply device in accordance with a second embodiment of the present invention. 
           [0017]      FIG. 3  is a schematic drawing showing an application example of the present invention. 
           [0018]      FIG. 4  corresponds to  FIG. 3 , showing the mobile electronic apparatus connected to the attached induction device. 
           [0019]      FIG. 5  shows another application example of the induction type power supply device according to the present invention. 
           [0020]      FIG. 6  shows still another application example of the induction type power supply device according to the present invention. 
           [0021]      FIG. 7  is a circuit block diagram of a power supply base unit for induction type power supply device in accordance with a third embodiment of the present invention 
           [0022]      FIG. 8  is a circuit block diagram of a power supply base unit for induction type power supply device in accordance with a fourth embodiment of the present invention. 
           [0023]      FIG. 9  is a circuit block diagram of an attached induction device for induction type power supply device in accordance with a fifth embodiment of the present invention. 
           [0024]      FIG. 10  is a circuit block diagram of an attached induction device for induction type power supply device in accordance with a sixth embodiment of the present invention. 
           [0025]      FIG. 11  illustrates an application example of the induction type power supply device in accordance with the sixth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0026]    Referring to  FIG. 1 , an induction type power supply device in accordance with a first embodiment of the present invention is shown comprising a power supply base unit  1  and an attached induction device  2 . 
         [0027]    The power supply base unit  1  comprises a connection interface  11 , an oscillator circuit  12  (either frequency modulable type or non-frequency modulable type), a driver circuit  13 , and a primary inductor  14 , which has installed therein a primary resonant circuit  141  and a primary coil  142 . The connection interface  11 , the oscillator circuit  12 , the driver circuit  13  and the primary inductor  14  are electrically connected in series. 
         [0028]    The attached induction device  2  comprises a secondary inductor  21  having installed therein a secondary coil  22  and a secondary resonant circuit  23 , a rectifier filter circuit  24 , a power management circuit  26 , and a connection device  27 . The secondary inductor  21 , the rectifier filter circuit  24 , the power management circuit  26  and the connection device  27  are electrically connected in series. 
         [0029]    After connection of the connection interface  11  of the power supply base unit  1  to an electric outlet  3 , the oscillator circuit  12  is electrically connected to produce an AC signal, which is then amplified by the driver circuit  13  and then sent to the primary resonant circuit  141  of the primary inductor  14  to obtain resonance, and then the AC signal is released through the primary coil  142 . 
         [0030]    As stated above, the secondary inductor  21  of the attached induction device  2  has installed therein a secondary coil  22  and a secondary resonant circuit  23 . When the secondary coil  22  is set in proximity to the primary coil  142  of the power supply base unit  1 , it releases the AC signal to the secondary resonant circuit  23  for converting into DC power supply by the rectifier filter circuit  24 . The DC power supply thus obtained is regulated by the power management circuit  26  to provide the desired voltage and current to an external mobile electronic apparatus  4  via the connection device  27 . Further, the connection device  27  can be a USB (Universal Serial Bus), Mini USB (Mini Universal Serial Bus), or any suitable electric connection interface. 
         [0031]      FIG. 2  is a circuit block diagram of an induction type power supply device in accordance with a second embodiment of the present invention. This second embodiment is substantially similar to the aforesaid first embodiment with the exception that the attached induction device  2  according to this second embodiment further comprises a charging module  25  electrically connected in series between the rectifier filter circuit  24  and the power management circuit  26 . The charging module  25  comprises a storage battery  252  electrically connected to the power management circuit  26 , and a charging circuit  251  electrically connected in series between the rectifier filter circuit  24  and the storage battery  252 . 
         [0032]    When the secondary coil  22  is set in proximity to the primary coil  142  of the power supply base unit  1 , it releases the AC signal to the secondary resonant circuit  23  for converting into DC power supply by the rectifier filter circuit  24 . The DC power supply thus obtained is then sent to the charging circuit  251  of the charging module  25  to charge the storage battery  252 . When travelling, a user can carry the attached induction device  2  separately and attach a mobile electronic apparatus to the connection device  27  of the attached induction device  2  to obtain the necessary working voltage and current from the storage battery  252  through the power management circuit  26 . 
         [0033]    Referring to  FIGS. 3˜6 , during application of the present invention, connect the connection interface  11  of the power supply base unit  1  to an electric outlet  3  and the attached induction device  2  to an external mobile electronic apparatus  4  that can be a cellular telephone, music player or any other commercial mini electronic apparatus, and then place the external mobile electronic apparatus  4  with the attached induction device  2  on the power supply base unit  1 . By means of magnetic induction between the primary resonant circuit  141  and primary coil  142  of the primary inductor  14  and the secondary coil  22  and secondary resonant circuit  23  of the secondary inductor  21 , the attached induction device  2  charges the external mobile electronic apparatus  4  by means of the connection device  27 . 
         [0034]      FIG. 7  is a circuit block diagram of a power supply base unit for induction type power supply device in accordance with a third embodiment of the present invention. According to this third embodiment, the power supply base unit  1  further comprises a feedback circuit  15  and a primary control circuit  16  connected in series between the primary coil  142  and the oscillator circuit  12 . During operation, power supply is connected to the oscillator circuit  12  to produce an AC signal, which is amplified by the driver circuit  13  and then sent to the primary resonant circuit  141  to obtain resonance and then to be released through the primary coil  142 . At the same time, the feedback circuit  15  feeds back the AC signal to the primary control circuit  16  for voltage/current analysis and comparison with a predetermined reference resonance. After comparison, the primary control circuit  16  outputs a control signal to the oscillator circuit  12  subject to comparison result, causing the oscillator circuit  12  to regulate the optimal resonant frequency. Thus, it is not necessary to add any extra adjusting component to compensate inductor or capacitor performance. In case an extra adjusting component is used, only a skilled professional person can perform the calibration. By means of the aforesaid feedback circuit  15  and primary control circuit  16 , the adjustment of the resonant frequency is done automatically. Therefore, the invention greatly simplifies the fabrication of the power supply base unit  1  and improves its yield rate. 
         [0035]      FIG. 8  is a circuit block diagram of a power supply base unit for induction type power supply device in accordance with a fourth embodiment of the present invention. According to this fourth embodiment, the power supply base unit  1  further comprises a signal processing module  17  electrically connected to the primary coil  142 . The signal processing module  17  comprises a detection circuit  171 , a signal processing circuit  172 , a code-decode circuit  173  and a frequency mixer circuit  174 . The detection circuit  171 , the signal processing circuit  172 , the code-decode circuit  173  and the frequency mixer circuit  174  are connected in series. The frequency mixer circuit  174  is electrically connected to the primary coil  141  of the primary inductor  14 . Further, the primary control circuit  16  is electrically connected to the code-encode circuit  173  and the connection interface  11 . The connection interface  11  can be a USB (Universal Serial Bus) or Mini USB (Mini Universal Serial Bus). When the connection interface  11  transmits an external media signal to the primary control circuit  16 , the primary control circuit  16  converts the media signal into a data signal, and then the code-encode circuit  173  encodes the data signal, and then the frequency signal mixer circuit  174  mixes the encoded data signal with a predetermined radio frequency signal and sends the mixed signal to the primary resonant circuit  141  and then the primary resonant circuit  141  sends the signal to the primary coil  142 . The detection circuit  171  is adapted to receive a modulated data signal from the primary coil  142  and to remove the radio frequency signal by means of frequency demodulation, and then to send the demodulated data signal to the signal processing circuit  172  for data processing, enabling the processed signal to be decoded by the encode-decode circuit  173  and sent back to the primary control circuit  16  for converting into a media data for output through the connection interface  11 . 
         [0036]      FIG. 9  is a circuit block diagram of an attached induction device for induction type power supply device in accordance with a fifth embodiment of the present invention. According to this embodiment, the attached induction device  2  further comprises a signal processing module  28  electrically connected with the secondary resonant circuit  23 . The signal processing module  28  comprises a signal processing circuit  281 , a secondary control circuit  282 , and a modulation circuit  283  for signal modulation. The modulation circuit  283  is electrically connected to the secondary resonant circuit  23 . The secondary control circuit  282  is electrically connected to the rectifier filter circuit  24 . When the secondary resonant circuit  23  sends a data signal to the signal processing circuit  281 , the signal processing circuit  281  demodulates the data signal and then sends the demodulated data signal to the secondary control circuit  282 , which converts the data signal into a media signal for output through the connection device  27 . 
         [0037]    Referring to  FIGS. 8 and 9  again, after connection of an external mobile electronic apparatus to the connection device  27  of the attached induction device  2  and connection of the connection interface  11  of the power supply base unit  1  to a computer, the connection interface  11  of the power supply base unit  1  transmits a data signal to the primary control circuit  16  for converting into a data signal. The converted data signal is then sent by the primary control circuit  16  to the code-encode circuit  173  for encoding. The encoded data signal is then mixed with a radio frequency signal by the frequency mixer circuit  174  and then sent to the primary inductor  14  for transmission to the secondary inductor  21  by means of magnetic induction. Upon receipt of the signal from the primary inductor  14 , the secondary inductor  21  sends the data signal to the signal processing circuit  281  for demodulation processing. After demodulation, the signal processing circuit  281  sends the demodulated data signal to the secondary control circuit  282  for converting into a media signal, which is then sent by the secondary control circuit  282  to the external mobile electronic apparatus  4  via the connection device  27 . 
         [0038]      FIG. 10  is a circuit block diagram of an attached induction device for induction type power supply device in accordance with a sixth embodiment of the present invention.  FIG. 11  illustrates an application example of the induction type power supply device in accordance with the sixth embodiment of the present invention. As illustrated in  FIG. 10 , the attached induction device  2  according to this sixth embodiment is substantially similar to that of the aforesaid fifth embodiment with the exception that this sixth embodiment eliminates the aforesaid charging module  25  and has an extra memory  29  installed therein. The memory  29  is electrically connected with the secondary control circuit  282  of the signal processing module  28 . According to this sixth embodiment, the connection interface  11  of the power supply base unit  1  can be connected to a computer (see  FIG. 11 ), allowing the computer to read storage data from the memory  29 , to write data into the memory  29 , or to make communication with an external mobile electronic apparatus being connected to the connection device  27  of the attached induction device  2 . Further, the attached induction device  2  can be made in the shape of a card, memory stick, or any of a variety of other configurations. 
         [0039]    In conclusion, the invention provides an induction type power supply device, which has the following advantages and features: 
         [0040]    1. The induction type power supply device comprises a power supply base unit  1  carrying a primary coil  142  and an attached induction device  2  carrying a secondary coil  22 . After connection of the power supply base unit  1  to an electric outlet  3 , power supply is transmitted from the power supply base unit  1  to the attached induction device  2  by means of magnetic induction to charge an external mobile electronic apparatus  4  that is connected to the attached induction device  2 . Multiple attached induction device  2  can be used with the power supply base unit  1  to charge multiple external mobile electronic apparatus  4 , thereby saving the cost. 
         [0041]    2. In one embodiment of the present invention, the attached induction device  2  has installed therein a charging module  25  formed of a charging circuit  251  and a storage battery  252  and electrically connected in series between the rectifier filter circuit  24  and the power management circuit  26 . By means of the power supply base unit  1 , the storage battery  252  is charged with city power supply. When one goes out, he(she) can carry the attached induction device  2  and use the attached induction device  2  to charge a mobile electronic apparatus  4  in case there is no any electric outlet available. 
         [0042]    3. Regular commercial mobile electronic apparatuses generally have at least one USB (Universal Serial Bus) and/or Mini USB (Mini Universal Serial Bus) for communication with external devices. The connection device  27  of the attached induction device  2  is compatible to most commercial mobile electronic apparatus. To fit a particular connection interface of a particular mobile electronic apparatus, a compatible attached induction device  2  can be selected for use with the same power supply base unit  1 . 
         [0043]    4. In another embodiment of the present invention, the power supply base unit  1  has installed therein a feedback circuit  15 , a primary control circuit  16  and an oscillator circuit  12 . The feedback circuit  15  feeds back the voltage at the primary resonant circuit  141  to the primary control circuit  16  for voltage analysis. Subject to the analysis result, the primary control circuit  16  controls the oscillator circuit  12  to regulate input AC voltage so that the power supply base unit  1  provides the optimal resonant frequency. 
         [0044]    5. When the connection device  27  of the attached induction device  2  is connected to an external mobile electronic apparatus  4  and the connection interface  11  of the power supply base unit  1  is connected to a computer, the connection interface  11  of the power supply base unit  1  transmits a media data signal to the primary control circuit  16  for converting into a data signal, which is then encoded by code-encode circuit  173  and mixed with a radio frequency signal by the frequency mixer circuit  174  and then transmitted by the primary inductor  14  to the secondary inductor  21  by means of resonant induction. Upon receipt of the data signal by the secondary inductor  21 , the data signal is sent by the secondary inductor  21  to the signal processing circuit  281  and the secondary control circuit  282  there the data signal is demodulated and converted into a media signal and then transmitted to the external mobile electronic apparatus  4  by the secondary control circuit  282 . Thus, the external mobile electronic apparatus  4  can receive data from the computer. 
         [0045]    A prototype of induction type power supply device has been constructed with the features of  FIGS. 1˜11 . The induction type power supply device functions smoothly to provide all of the features disclosed earlier. 
         [0046]    Although particular embodiments of the invention have 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.