Wireless Battery Charging Systems And Methods

Abstract

Example systems and methods are described that wirelessly charge a rechargeable battery associated with a lock. In one implementation, a rechargeable battery is electrically coupled to an electronic lock module associated with a door corresponding to a door frame. An electronic control module associated with the door frame and physically separate from the electronic lock module generates a wireless charging link between the electronic control module and the electronic lock module. The electronic control module transmits a charging signal to the electronic lock module via the wireless charging link, and the electronic lock module uses this charging signal to charge the rechargeable battery. The implementation also includes a lock associated with the door that can be locked or unlocked by the electronic lock module.

1 . An apparatus comprising:
 an electronic lock module associated with a door corresponding to a door frame;   a rechargeable battery electrically coupled to the electronic lock module;   an electronic control module associated with the door frame and physically separate from the electronic lock module, wherein the electronic control module is configured to generate a wireless charging link between the electronic control module and the electronic lock module, wherein the electronic control module transmits a charging signal to the electronic lock module via the wireless charging link, and wherein the electronic lock module uses the charging signal to charge the rechargeable battery; and   a lock associated with the door that can be locked or unlocked by the electronic lock module.   
     
     
         2 . The apparatus according to  claim 1 , wherein the charging signal is transmitted continuously. 
     
     
         3 . The apparatus according to  claim 1 , wherein the charging signal is transmitted non-continuously. 
     
     
         4 . The apparatus according to  claim 1 , further including a bidirectional data communications link that transmits data signals between the electronic control module and the electronic lock module. 
     
     
         5 . The apparatus according to  claim 4 , wherein the bidirectional data communications link is comprised of two unidirectional RF data communication links, wherein each unidirectional RF data communications link transmits a signal in a direction opposite to the other unidirectional RF data communications link, and each unidirectional RF data communications link transmits an RF frequency that is different from the other unidirectional RF data communications link. 
     
     
         6 . The apparatus according to  claim 5 , wherein each of the electronic control module and the electronic lock module has one RF antenna for each of the unidirectional RF data communications links comprising the bidirectional data link. 
     
     
         7 . The apparatus according to  claim 6 , wherein the dimensions of the RF antennas are functions of the physical separation between the electronic control module and the electronic lock module. 
     
     
         8 . The apparatus according to  claim 1 , wherein the electronic lock module monitors the charge on the rechargeable battery and transmits the status of the charge on the rechargeable battery over the bidirectional data communications link to the electronic control module. 
     
     
         9 . The apparatus according to  claim 1 , wherein the electronic control module receives the status of the charge on the rechargeable battery from the electronic lock module over the bidirectional data communications link. 
     
     
         10 . The apparatus according to  claim 1 , wherein the electronic control module compares the status of the charge on the rechargeable battery with a threshold value. 
     
     
         11 . The apparatus according to  claim 10 , wherein the electronic control module transmits the charging signal over the wireless charging link when the electronic control module determines that the charge on the rechargeable battery has fallen below the threshold value. 
     
     
         12 . The apparatus according to  claim 1 , wherein the rechargeable battery powers the electronic lock module. 
     
     
         13 . The apparatus according to  claim 1 , further comprising an access control module electrically coupled to the electronic control module. 
     
     
         14 . The apparatus according to  claim 13 , wherein the electronic control module transmits user credentials to the access control module, and the access control module is configured to perform an authentication function on the user data to determine whether the door should be unlocked and communicates the results of the authentication to the electronic control module. 
     
     
         15 . The apparatus according to  claim 1 , wherein the electronic lock module receives an authorization signal to unlock the door via the bidirectional data communications link from the electronic control module. 
     
     
         16 . The apparatus according to  claim 1 , wherein the electronic lock module periodically transmits a heartbeat signal over the bidirectional data communications link to the electronic control module. 
     
     
         17 . The apparatus according to  claim 1 , wherein the electronic lock module monitors a status of the door. 
     
     
         18 . The apparatus according to  claim 17 , wherein the electronic lock module transmits the status of the door to the electronic control module over the bidirectional data communications link. 
     
     
         19 . An apparatus comprising:
 an electronic lock module associated with a door corresponding to a door frame;   a rechargeable battery electrically coupled to the electronic lock module;   an electronic control module associated with the door frame and physically separate from the electronic lock module, wherein the electronic control module is configured to generate a wireless charging link between the electronic control module and the electronic lock module, wherein the wireless charging link comprises an inductively coupled charging link, wherein the electronic control module transmits a charging signal to the electronic lock module via the wireless charging link, and wherein the electronic lock module uses the charging signal to charge the rechargeable battery; and   a lock associated with the door that can be locked or unlocked by the electronic lock module.   
     
     
         20 . The apparatus according to  claim 19 , wherein the charging signal is transmitted continuously. 
     
     
         21 . The apparatus according to  claim 19 , wherein the charging signal is transmitted non-continuously. 
     
     
         22 . The apparatus according to  claim 19 , wherein the inductively coupled charging link is generated by a transmitter and a receiver that are inductively coupled. 
     
     
         23 . The apparatus according to  claim 22 , wherein the transmitter and receiver are both tuned to the same resonant frequency. 
     
     
         24 . The apparatus according to  claim 22 , wherein the transmitter and the receiver comprise solenoids with ferrite cores. 
     
     
         25 . The apparatus according to  claim 22 , wherein the transmitter and the receiver comprise air wound coils. 
     
     
         26 . The apparatus according to  claim 22 , wherein the transmitter and the receiver comprise coils with cores comprised of materials with high magnetic permeability. 
     
     
         27 . A method comprising:
 determining a status of a charge on a rechargeable battery used to power an electronic door lock;   transmitting, over a first wireless communications link, the status of the charge on the rechargeable battery to a receiver;   receiving wirelessly the status of the charge on the rechargeable battery via the wireless communications link;   comparing the status of the charge on the rechargeable battery with a threshold value;   transmitting, over a second wireless communications link, a charging signal to recharge the rechargeable battery;   receiving the charging signal over the second wireless communications link; and   charging the rechargeable battery using the charging signal.