Method of generating load variation for detecting wireless power receiving unit in wireless charging, and wireless power receiving unit

Abstract

A method of controlling a wireless power receiver. The method includes receiving, by a power receiver, power from a wireless power transmitter; receiving, from the wireless power transmitter, a time set value that is set for checking cross connection; in response to receiving the time set value, generating a power variation in the wireless power receiver by converting a load status from a first load status to a second load status; and maintaining the second load status for a time corresponding to the received time set value.

What is claimed is: 
     
       1. A method of controlling a wireless power receiver, the method comprising:
 receiving, by a power receiver, power from a wireless power transmitter; 
 receiving, from the wireless power transmitter, a time set value that is set for checking cross connection, wherein the time set value is set by the wireless power transmitter; 
 in response to receiving the time set value, generating a power variation in the wireless power receiver by converting a load status from a first load status to a second load status; and 
 maintaining the second load status for a time corresponding to the received time set value. 
 
     
     
       2. The method of  claim 1 , further comprising:
 returning to the first load status, upon a lapse of the time corresponding to the received time set value. 
 
     
     
       3. The method of  claim 1 , wherein converting the load status comprises switching a switch connected to a dummy load to an ON state in response to receiving the time set value, and
 wherein maintaining the second load status comprises maintaining the ON state for the time corresponding to the received time set value. 
 
     
     
       4. The method of  claim 3 , further comprising:
 switching the switch to an OFF state, upon a lapse of time corresponding to the received time set value. 
 
     
     
       5. The method of  claim 1 , wherein the power variation in the wireless power receiver is caused by a load variation due to the conversion of the load status. 
     
     
       6. A wireless power receiver, comprising:
 a power receiver configured to receive power from a wireless power transmitter; 
 a communication module configured to receive, from the wireless power transmitter, a time set value that is set for checking cross connection; and 
 a controller configured to:
 receive, from the wireless power transmitter, a time set value that is set for checking cross connection, by using the communication module, wherein the time set value is set by the wireless power transmitter,  
 generate a power variation in the wireless power receiver by converting a load status from a first load status to a second load status, and 
 maintain the second load status for time corresponding to the received time set value. 
 
 
     
     
       7. The wireless power receiver of  claim 6 , wherein the controller is further configured to return to the first load status, upon a lapse of the time corresponding to the received time set value. 
     
     
       8. The wireless power receiver of  claim 6 , further comprising:
 a dummy load connected in parallel between the power receiver and a load of the wireless power receiver; and 
 a switch configured to selectively connect the dummy load to the power receiver. 
 
     
     
       9. The wireless power receiver of  claim 8 , wherein the controller is further configured to generate the load variation by switching the switch from an OFF state to an ON state and to maintain the ON state for the time corresponding to the received time set value. 
     
     
       10. The wireless power receiver of  claim 9 , wherein the controller is further configured to return to the first load status by switching the switch from the ON state to the OFF state, upon a lapse of the time corresponding to the received time set value. 
     
     
       11. The wireless power receiver of  claim 6 , wherein the power variation in the wireless power receiver is caused by a load variation due to the conversion of the load status. 
     
     
       12. A method for controlling a wireless power transmitter, the method comprising:
 transmitting, to a wireless power receiver, a time set value that is set for checking cross connection, wherein the time set value is set by the wireless power transmitter; 
 detecting a load variation of the wireless power receiver; 
 comparing the time set value with a period of the load variation; 
 determining whether the wireless power receiver is cross-connected, based on the comparison result; and 
 in response to determining that the wireless power receiver is cross-connected, transmitting a power receiving unit (PRU) control signal with a permission field indicating that the wireless power receiver is not permitted due to the cross connection. 
 
     
     
       13. The method of  claim 12 , further comprising:
 transmitting power to the wireless power receiver, in response to determining that the wireless power receiver is not cross-connected. 
 
     
     
       14. A wireless power transmitter, comprising:
 a communication module configured to transmit, to a wireless power receiver, a time set value that is set for checking cross connection; and 
 a controller configured to:
 transmit, to a wireless power receiver, a time set value that is set for checking cross connection by using the communication module, wherein the time set value is set by the wireless power transmitter,  
 detect a load variation of the wireless power receiver, 
 compare the time set value with a period of the load variation, 
 determine whether the wireless power receiver is cross-connected, based on the comparison result, and 
 in response to determining that the wireless power receiver is cross-connected, transmit, through the communication module, a power receiving unit (PRU) control signal with a permission field indicating that the wireless power receiver is not permitted due to the cross connection. 
 
 
     
     
       15. The wireless power transmitter of  claim 14 , further comprising a power transmitter, and,
 wherein the controller is further configured to transmit, through the power transmitter, power, in response to determining that the wireless power receiver is not cross-connected.