System and method for alignment and compatibility detection for a wireless power transfer system

A method of receiving charging power wirelessly, the method comprising:

• receiving, by a receiver communication circuit, an indication of a value of at least one characteristic of a charging transmitter;
• measuring, by a sensor circuit, a value of an a short circuit current or an open circuit voltage of a receive coil;
• comparing, by a controller, the value of the short circuit current or the open circuit voltage to a threshold charging parameter, the threshold set at a level that provides charging power sufficient to charge a load;
• and
• initiating, by the controller, receiving the charging power from the charging transmitter based on the short circuit current or the open circuit voltage of the receive coil being greater than or equal to the threshold charging parameter.

An apparatus for receiving charging power wirelessly, the apparatus comprising:

• means for receiving an indication of a value of at least one characteristic of a charging transmitter, the means for receiving the indication being operatively connected to a load;
• means for measuring a value of a short circuit current or an open circuit voltage of the means for receiving the indication;
• means for comparing the value of the short circuit current or the open circuit voltage to a threshold charging parameter, the threshold set at a level that provides charging power sufficient to charge the load;
• and
• means for initiating receiving the charging power from the charging transmitter based on the short circuit current or the open circuit voltage of the means for receiving the indication being greater than or equal to the threshold charging parameter.

An apparatus for transmitting charging power wirelessly to a receive coil of a receiver, the apparatus comprising:

• a transmit circuit coupled to a transmit coil;
• a sensor circuit coupled to the transmit circuit, the sensor circuit configured to measure a value of at least one characteristic of the transmit circuit;
• and
• a communication circuit configured to transmit an indication of the value of the at least one characteristic of the transmit circuit to the receiver, the receiver receiving the indication causing the receiver to determine a threshold charging parameter based on the indication and causing the receiver to initiate receiving the charging power based on a short circuit current or an open circuit voltage of the receive coil being greater than or equal to the threshold charging parameter.