Timing verification in precision power level control systems for wireless power transmission

A power transmitter for wireless power transfer at an operating frequency selected from a range of about 87 kilohertz (kHz) to about 205 kHz, the power transmitter comprising:

• a control and communications unit configured to:
• provide power control signals to control a power level of a power signal configured for transmission to a power receiver,
• provide a power timing request to an external power supply, the power timing request having a requested power input, the external power supply configured for communication with the control and communications unit and for providing DC power to an inverter circuit,
• determine a monitored input by monitoring power input to the power transmitter from the external power supply,
• determine if the monitored input matches the requested power input, within a timing interval, the timing interval comprising a minimum time for response from the external power supply to supply input power to the power transmitter for wireless power transmission,
• if the monitored input matches the requested power input within the timing interval:
• verify timing for the external power supply and commence wireless power transmission, and
• provide a driving signal for the power signal;
• the inverter circuit configured to receive the DC power from the external power supply, receive the driving signal from the control and communications unit, and convert the DC power to the power signal based on the driving signal;
• a coil configured to receive the power signal from the inverter circuit and transmit the power signal to the power receiver, the coil formed of wound Litz wire and including at least one layer, the coil defining, at least, a top face;
• and
• a shielding comprising a ferrite core and defining a cavity, the cavity configured such that the ferrite core substantially surrounds all but the top face of the coil.

A system for wireless power transfer at an operating frequency selected from a range of about 87 kilohertz (kHz) to about 205 kHz, the system comprising:

• a power transmitter including:
• a control and communications unit configured to:
• provide power control signals to control a power level of a power signal configured for transmission to a power receiver,
• provide a power timing request to an external power supply, the power timing request having a requested power input, the external power supply configured for communication with the control and communications unit and for providing DC power to an inverter circuit,
• determine a monitored input by monitoring power input to the power transmitter from the external power supply,
• determine if the monitored input matches the requested power input, within a timing interval, the timing interval comprising a minimum time for response from the external power supply to supply input power to the power transmitter for wireless power transmission,
• if the monitored input matches the requested power input within the timing interval:
• verify timing for the external power supply and commence wireless power transmission, and
• provide a driving signal for the power signal,
• the inverter circuit configured to receive the DC power from the external power supply, receive the driving signal from the control and communications unit, and convert the DC power to the power signal, based on the driving signal,
• a coil configured to receive the power signal from the inverter circuit and transmit the power signal to the power receiver, the coil formed of wound Litz wire and including at least one layer, the coil defining, at least, a top face, and
• a shielding comprising a ferrite core and defining a cavity, the cavity configured such that the ferrite core substantially surrounds all but the top face of the coil;
• and
• the external power supply that is configured to configure the DC power based on the power control signals, the external power supply including:
• a voltage regulator, and
• a power supply controller configured to:
• receive the input power control signals,
• generate voltage regulation instructions for altering the DC power, based on the power control signals, the voltage regulation instructions including voltage step up instructions or voltage step down instructions for the voltage regulator, the voltage step up instructions and voltage step down instructions having a step level, the step level being a change in voltage at which the voltage regulator is configured to step up or step down the DC voltage of the DC power, and
• provide the voltage regulation instructions to the voltage regulator to control the DC voltage of the DC power.