Charging pad and a method for charging one or more receiver devices

Abstract

A charging pad ( 130 ) for charging one or more receiver devices ( 106, 108 ) is disclosed. The charging pad ( 130 ) includes a power drive unit ( 110 ) configured to generate a first AC voltage signal having a first frequency and a second AC voltage signal having a second frequency. Further, the charging pad ( 130 ) includes a transmitting unit ( 114 ) including a single power exchange coil ( 120 ) coupled to the power drive unit ( 110 ), wherein the single power exchange coil ( 120 ) includes a first coil segment ( 212 ) configured to transmit the first AC voltage signal having the first frequency when the first AC voltage signal is received from the power drive unit ( 110 ). Also, the single power exchange coil ( 120 ) includes a second coil segment ( 214 ) configured to transmit the second AC voltage signal having the second frequency when the second AC voltage signal is received from the power drive unit ( 110 ).

1 . A wireless charging device comprising:
 a power drive unit capable of generating
 a first AC voltage signal having a first frequency according to a high frequency standard or 
   a second AC voltage signal having a second frequency according to a low frequency standard; and a transmitting unit comprising a power exchange coil coupled to the power drive unit, the power exchange coil configured to:
 resonate at the first frequency to transmit the first AC voltage signal according to the high frequency standard when the transmitting unit receives the first AC voltage signal; and 
 resonate at the second frequency to transmit the second AC voltage signal according to the low frequency standard when the transmitting unit receives the second AC voltage signal. 
   
     
     
         2 . The wireless charging device of  claim 1 , wherein the transmitting unit further comprises
 a first resonator comprising a first coil segment and a first capacitor coupled to the first coil segment, wherein the first resonator is configured to resonate at the first frequency; and   a second resonator comprising a second coil segment and a second capacitor coupled to the second coil segment, wherein the second resonator is configured to resonate at the second frequency.   
     
     
         3 . The wireless charging device of  claim 1 , wherein the power exchange coil includes a first coil segment that is configured to inductively transmit the first AC voltage signal having the first frequency to a first receiver device according to the high frequency standard. 
     
     
         4 . The wireless charging device of  claim 3 , wherein the power exchange coil includes a second coil segment that is configured to inductively transmit the second AC voltage signal having the second frequency to a second receiver device according to the low frequency standard. 
     
     
         5 . The wireless charging device of  claim 1 , wherein the power exchange coil includes:
 a first coil segment that has a first internal capacitance and a first internal inductance such that the first coil segment is configured to resonate at the first frequency; and   a second coil segment that has a second internal capacitance and a second internal inductance such that the second coil segment is configured to resonate at the second frequency.   
     
     
         6 . The wireless charging device of  claim 1 , wherein the power exchange coil includes at least a first coil segment and a second coil segment, and wherein the first coil segment and the second coil segment are interwound spirally to form a swiss roll structure. 
     
     
         7 . The wireless charging device of  claim 11 , further comprising:
 a control unit operatively coupled to the power drive unit and configured to control the power drive unit according to the high frequency standard or the low frequency standard.   
     
     
         8 . The wireless charging device of  claim 7 , wherein the control unit is further configured to send at least one of a first frequency control signal and a second frequency control signal to the power drive unit. 
     
     
         9 . The wireless charging device f  claim 8 , wherein the power drive unit comprises a converting unit configured to:
 convert a DC voltage signal of an input power to the first AC voltage signal having the first frequency if the first frequency control signal is received from the control unit; and   convert the DC voltage signal of the input power to the second AC voltage signal having the second frequency if the second frequency control signal is received from the control unit.   
     
     
         10 . The wireless charging device of  claim 1 , wherein the power drive unit comprises an oscillating unit configured to generate the first AC voltage signal having the first frequency or the second AC voltage signal having the second frequency. 
     
     
         11 . The wireless charging device of  claim 10 , wherein the oscillating unit includes:
 a first oscillator tuned to the first frequency; and   a second oscillator tuned to the second frequency.   
     
     
         12 . The wireless charging device of  claim 1 , wherein the power drive unit and the transmitting unit are constructed in a common charging pad, the charging pad capable of transmitting power according to both the high frequency standard and the low frequency standard depending on which frequency standard is compatible with a particular receiver device. 
     
     
         13 . The wireless charging device of  claim 1 ,
 wherein the high frequency standard defines a frequency range over 200 kHz; and   wherein the low frequency standard defines a frequency range below 200 kHz.   
     
     
         14 . The wireless charging device of  claim 1 , wherein the power drive unit comprises a drive coil magnetically coupled to the power exchange coil of the transmitting unit. 
     
     
         15 . A method of a wireless charging device, comprising:
 generating, by a power drive unit ( 110 ), either or both of a first AC voltage signal having a first frequency according to a high frequency standard or a second AC voltage signal having a second frequency according to a low frequency standard; and   transmitting, via a power exchange coil coupled to the power drive unit, either or both of the first AC voltage signal or the second AC voltage signal, wherein transmitting includes the power exchange coil:
 resonating at the first frequency to transmit the first AC voltage signal according to the high frequency standard when the transmitting unit receives the first AC voltage signal, and 
   resonating at the second frequency to transmit the second AC voltage signal according to the low frequency standard when the transmitting unit receives the second AC voltage signal.   
     
     
         16 . The method of  claim 15 , wherein the power exchange coil includes a first coil segment that is configured to inductively transmit the first AC voltage signal having the first frequency to a first receiver device according to the high frequency standard, and
 a second coil segment that is configured to inductively transmit the second AC voltage signal having the second frequency to a second receiver device according to the low frequency standard.   
     
     
         17 . The method of  claim 15 , further comprising:
 controlling, via a control unit, the power drive unit according to the high frequency standard or the low frequency standard.   
     
     
         18 . The method of  claim 17 , wherein controlling the power drive unit includes
 sending at least one of a first frequency control signal and a second frequency control signal from the control unit to the power drive unit.