Wireless power Tx to Tx conflict and protection

A method of operating a wireless power device, comprising:

• determining an operating mode of the wireless power device;
• in a transmit mode
• determining presence of a transmit power from a second wireless power device,
• when the transmit power from the second wireless power device is detected, providing a collision alert and proceeding to an off state where the wireless power device does not transmit wireless power, and
• when transmit power from the second wireless power device is not detected, activating a transmit driver to transmit wireless power from the wireless power device,
• wherein determining presence of a transmit power includes monitoring a rectified voltage using discrete diode and demodulation circuitry to provide the collision alert.

A method of operating a wireless power device, comprising:

• determining an operating mode of the wireless power device;
• in a transmit mode
• determining presence of a transmit power from a second wireless power device,
• when the transmit power from the second wireless power device is detected, providing a collision alert and proceeding to an off state, and
• when the transmit power from the second wireless power device is not detected, activating a transmit driver to transmit wireless power from the wireless power device,
• wherein determining presence of a transmit power includes monitoring a frequency of a voltage across a wireless coil with a frequency counter.

A wireless power device, comprising:

• a rectifier circuit coupled to a coil;
• a transmit driver coupled to the rectifier circuit, the transmit driver configured to provide power to the rectifier circuit during wireless power transmission through the coil;
• a transmit detect circuit configured to detect receipt of transmitted wireless power from a second wireless power device at the coil, wherein the transmit detect circuit detects receipt of transmitted wireless power with a frequency counter coupled to detect incoming voltage or current at the coil to provide a signal;
• and
• a controller coupled to the transmit driver and the transmit detect circuit, the controller receiving the signal from the transmit detect circuit and providing an alert of the presence of the transmitted wireless power, the controller activating the transmit driver to transmit wireless power in absence of the signal and a collision alert in the presence of the signal.