Wireless Power System

• US 20140159500A1
• Filed: 07/16/2013
• Published: 06/12/2014
• Est. Priority Date: 07/18/2012
• Status: Active Grant

• Current Assignee: WiPQTUS Inc.
• Original Assignee: WiPQTUS Inc.
• Inventors: Sankar, Ganapathy, Singh, Manjit
• Granted Patent: US 9,472,958 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

A higher power wireless power transmitter (HPWPT) including a first, second and third circuit and a transmit coil for wirelessly powering a lower power wireless power receiver (LPWPR) is provided. The first circuit is a switch network. The second circuit is variable impedance network and/or a tuning network. The third circuit is a control logic circuit configured to change the input voltage source or topology of the first circuit, to change the impedance and/or tuning characteristics of the second circuit, to select the transmit coil, vary frequency or duty cycle of the PWM signal or any combination thereof. The change in the input voltage or topology of first circuit or change in impedance or tuning characteristics of second circuit or change in the transmit coil used or the applied constraints on the frequency and duty cycle of the PWM signal constrain the maximum power transmitted by the HPWPT to LPWPR.

Claims

1. A wireless power transmitter for powering a wireless power receiver, said wireless power transmitter comprising:

a first circuit configured to receive an input voltage;

a second circuit connected between said first circuit and a transmitter coil, said transmitter coil configured to wirelessly transmit power to said wireless power receiver; and

a third circuit configured to provide a pulse width modulated signal to said first circuit, wherein said third circuit is configured to perform one or more of;

changing said input voltage to said first circuit;

driving of said first circuit to change a topology of said first circuit;

driving of said second circuit to change tuning characteristics and/or impedance offered of said second circuit;

changing said transmitter coil that is used to deliver power wirelessly to said wireless power receiver; and

constraining frequency and duty cycle of said pulse width modulated signal to a range of values and varying said frequency and said duty cycle of said pulse width modulated signal within those respective ranges;

whereby said change in one of said input voltage, said topology of said first circuit, said tuning characteristics and/or impedance offered of said second circuit, said transmitter coil, said frequency range of said pulse width modulated signal, and said duty cycle range of said pulse width modulated signal limits said power transmitted by said wireless power transmitter to said wireless power receiver.

2. The wireless power transmitter of claim 1, wherein said first circuit is a switch network.

3. The wireless power transmitter of claim 1, wherein said second circuit is one of a variable matching circuit and/or a tuning network.

4. The wireless power transmitter of claim 1, wherein said second circuit comprises one or more of passive electronic components, active electronic components, and electronic switches for limiting said power transmitted to said wireless power receiver.

5. The wireless power transmitter of claim 1, wherein said third circuit is a control logic circuit.

6. The wireless power transmitter of claim 1, wherein said first circuit is configured as an inverter in one of a plurality of inverter topologies.

7. The wireless power transmitter of claim 1, wherein said third circuit is configured to drive said first circuit to change a topology of said first circuit from a Class D full bridge inverter to a Class D half bridge inverter and vice versa.

8. The wireless power transmitter of claim 1, wherein said third circuit is configured to drive said first circuit to change a topology of said first circuit from a Class D inverter to a Class E inverter and vice versa.

9. A method for powering a wireless power receiver using a wireless power transmitter, comprising:

providing said wireless power transmitter comprising;

a first circuit configured to receive an input voltage;

a second circuit connected between said first circuit and a transmitter coil, said transmitter coil configured to wirelessly transmit power to said wireless power receiver; and

a third circuit configured to provide a pulse width modulated signal to said first circuit;

configuring said third circuit of said wireless power transmitter to perform one or more of;

changing said input voltage to said first circuit;

driving of said first circuit to change a topology of said first circuit;

driving of said second circuit to change tuning characteristics and/or impedance offered of said second circuit;

changing said transmitter coil that is used to deliver power wirelessly to said wireless power receiver; and

constraining frequency and duty cycle of said pulse width modulated signal to a range of values and varying said frequency and said duty cycle of said pulse width modulated signal within those respective ranges;

whereby said change in one of said input voltage, said topology of said first circuit, said tuning characteristics and/or impedance offered of said second circuit, said transmitter coil, said frequency range of said pulse width modulated signal, and said duty cycle range of said pulse width modulated signal limits said power transmitted by said wireless power transmitter to said wireless power receiver.

10. The method of claim 9, further comprising determining maximum power that is to be transmitted to said wireless power receiver by said third circuit of said wireless power transmitter, on receiving one of an implicit message and an explicit message from said wireless power receiver.

11. The method of claim 10, further comprising configurably adjusting said maximum power transmitted to said wireless power receiver, by said third circuit configuring said first circuit and/or said second circuit in said wireless power transmitter, based on said determination.

12. The method of claim 9, further comprising configurably adjusting said maximum power transmitted to said wireless power receiver by selecting an appropriate said input voltage for said first circuit, or by changing said topology of said first circuit, or by changing said impedance offered or by changing said tuning characteristics of said second circuit or by changing said transmit coil used to deliver power to said wireless power receiver, or by constraining said wireless power transmitter to operate in a frequency regime or a duty cycle regime or by a combination thereof.