System and method for triggering power transfer across an inductive power coupling and non resonant transmission

Patent metadata

Field	Value
Publication number	US-2016248280-A1
Application number	US-201615146363-A
Country	US
Kind code	A1
Filing date	May 4, 2016
Priority date	May 3, 2012
Publication date	Aug 25, 2016
Grant date	—

Abstract

A triggerable power transmitter for power transmission from a primary coil to an inductively coupled secondary coil in a power receiver has a primary coil; a driver for electrically driving the primary coil; a probing coil receives analog signals indicative of resonance properties of the primary coil; analog filters may be used to filter frequencies, and a processor capable of generating digital information in response to the analog signal and determining if said primary coil is coupled to a secondary coil based on the digital information, and triggering power from the primary coil to said secondary coil when said primary coil is inductively coupled to said secondary coil. A resistor may be selectably connected in series with the primary coil and shorted out when power is transmitted.

First claim

1 . A triggerable power transmitter for power transmission from a primary coil in the power transmitter to an inductively coupled secondary coil in a power receiver comprising:
a primary coil, capable of being inductively coupled to a secondary coil in a power receiver; a driver, capable of electrically driving said primary coil; a probing coil, capable of receiving analog signals indicative of resonance properties of said primary coil; and a processor, capable of generating digital information in response to said analog signal and capable of: determining if said primary coil is coupled to a secondary coil based on said digital information, and controlling said driver to transmit power from said primary coil to said secondary coil when said primary coil is inductively coupled to said secondary coil.

2 . The power transmitter of claim 1 , and comprising a resistor, placed in series to primary coil and capable of providing said front end with analog signal indicative of resonance properties of said primary coil.

3 . The power transmitter of claim 4 , and comprising a switch placed in parallel to said resistor and capable of shorting out said resistor when power is transmitted from said primary coil to said secondary coil.

4 . A triggerable power transmitter for power transmission from a primary coil in the power transmitter to an inductively coupled secondary coil in a power receiver comprising:
a primary coil, capable of being inductively coupled to a secondary coil in a power receiver; a driver, capable of electrically driving said primary coil; a front end, capable of receiving analog signal indicative of resonance properties of said primary coil and capable of generating digital information in response to said analog signal; a resistor, connectable in series with said primary coil and capable of providing said front end with an analog signal indicative of resonance properties of said primary coil; a switch, in parallel to said resistor and capable of shorting out said resistor when power is transmitted from said primary coil to said secondary coil; and a processor, receiving said digital information and capable of: determining if said primary coil is coupled to a secondary coil based on said digital information, and controlling said driver to transmit power from said primary coil to said secondary coil when said primary coil is inductively coupled to said secondary coil.

5 . The power transmitter of claim 4 further comprising at least one analog filter tuned to a specific resonance frequency.

6 . The power transmitter of claim 4 further comprising a set of RLC circuits, each tuned to one specific resonance frequency.

7 . The power transmitter of claim 4 , and comprising a probing coil, said probing coil is capable of providing said front end with analog signal indicative of resonance properties of said primary coil.

8 . A method of triggering power transmission in inductively coupled power transmission system comprising:
a. waiting a time duration; b. electrically exciting a primary coil in a power transmitter; c. receiving signal indicative of resonance properties of said primary coil; d. applying at least one tuned filter to a signal indicative of resonance properties of said primary coil thereby determining if a secondary coil in a power receiver is inductively coupled to said primary coil; and e. triggering power transmission from said primary coil to said secondary coil if said secondary coil is inductively coupled to said primary coil, or repeating steps a-d if said secondary coil is not inductively coupled to said primary coil.

9 . The method of triggering power transmission of claim 8 , wherein said applying at least one tuned filter to a signal indicative of resonance properties of said primary coil comprises applying a plurality of analog filters.

10 . The method of triggering power transmission of claim 8 , wherein said exciting of a primary coil in a power transmitter comprises applying a short electric pulse to said primary coil.

11 . The method of triggering power transmission of claim 8 , wherein said determining if a secondary coil is inductively coupled to said primary coil comprises determining a change in resonance frequency of said primary coil.

12 . The method of triggering power transmission of claim 11 , wherein said change in resonance frequency of said primary coil is a reduction of said resonance frequency.

13 . The method of triggering power transmission of claim 8 , wherein said determining if a secondary coil is inductively coupled to said primary coil comprises determining a change in effective inductance of said primary coil.

14 . The method of triggering power transmission of claim 8 , wherein said determining if a secondary coil is inductively coupled to said primary coil further comprises determining a change in effective resistance of said primary coil.

15 . The method of triggering power transmission of claim 8 , wherein said determining if a secondary coil is inductively coupled to said primary coil comprises determining a match between: values indicative of effective inductance of said primary coil; and values indicative of effective resistance of said primary coil to at least one set of values in a list of values associated with a primary coil inductively coupled to a plurality of different types of power receivers.

16 . The method of triggering power transmission of claim 15 , wherein said triggering power transmission from said primary coil to said secondary coil if said secondary coil is inductively coupled to said primary coil comprises controlling the power transmission according to type of power receiver associated with the matched values indicative of effective inductance of said primary coil; and values indicative of effective resistance of said primary coil.

17 . The method of triggering power transmission of claim 16 , wherein said repeating steps a-d if said secondary coil is not inductively coupled to said primary coil further comprising issuing a warning if said signal indicative of resonance properties of said primary coil indicates that an object other than a secondary coil is inductively coupled to said primary coil.

18 . The method of triggering power transmission of claim 8 , wherein said exciting of a primary coil in a power transmitter comprises short duration activation of a driver used for driving said primary coil during power transmission from said primary coil to said secondary coil.

19 . The method of triggering power transmission of claim 8 , wherein said exciting of a primary coil in a power transmitter comprises activation of a driver used for driving said primary coil during power transmission from said primary coil to said secondary coil at power level significantly reduced compared to power levels used for driving said primary coil during power transmission.

20 . The method of triggering power transmission of claim 19 , wherein:
said exciting of a primary coil in a power transmitter at reduced power level comprising exciting said primary coil at a plurality of frequencies, and said determining if a secondary coil in a power receiver is inductively coupled to said primary coil comprises assessing frequency response of said primary coil.

Assignees

• Powermat Tech Ltd

Inventors

• Ben-Shalom Amir
• Greenwald Oola
• Rofe Arik
• Moti Asheri
• Mach Elieser
• Moshkovich Oz
• Raveh Guy

Classifications

• H02J50/10

  using inductive coupling · CPC title

• H02J7/70

  characterised by the mechanical construction · CPC title

• A61N1/3787

  from an external energy source · CPC title

• H02J50/80

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title

• G05B13/0205

  not using a model or a simulator of the controlled system · CPC title