Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 1 of 23 PageID #: 19
`
`Exhibit A
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 2 of 23 PageID #: 20
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 2 of 23 PagelD #: 20
`
`US 9,906,067 B1
` Page 2
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`2015/0333797 AL*
`
`2015/0124412 Al*
`
`5/2015 Keegan HO2M 7/5387
`361/734
`11/2015 Nejatali oo... HO04B 5/0043
`375/376
`2015/0380978 AL* 12/2015 Toivola we HO02J 7/025
`320/108
`
`* cited by examiner
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 3 of 23 PageID #: 21
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 3 of 23 PagelD #: 21
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 1 of 11
`
`US 9,906,067 B1
`
`120
`
`110
`
`
`
`
`WIRELESS
`
`
`
`INTERFACE
`
`4150A
`
`BATTERY
`
`=~ 160 | BATTERY
`
`140
`
`130
`
`+ WIRELESS
`
`Vg
`
`Nvg
`
`C402 |
`
`[501
`
`
`
`| |
`
`CTT TT TTS 7
`|
`Ls
`Ls
`|
`
`Cy
`In
`—_—_
`=
`C402
`
`i/N
`Cy
`——S
`[LS
`C403S
`
`420
`
`
`
`L502
`2Ly
`IK
`
`
`
`|
`
`Yp
`
`\p
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 4 of 23 PageID #: 22
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 4 of 23 PagelD #: 22
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 2 of 11
`
`US 9,906,067 B1
`
`80rd9070
`
`D408
`<4
`
`D406
`
`V202
`
`D402
`<]
`
`
`
`
`|
`
`©2
`
`0
`
`
`
`i|[|[|i[||||L0¢0||{[[|[|[|Lord—2V||a||
`
`c0vO
`
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 5 of 23 PageID #: 23
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 5 of 23 PagelD #: 23
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 3 of 11
`
`US 9,906,067 B1
`
`LL
`=—
`
`So
`
`oO
`a
`re)
`
`< =w
`
`n
`
`,
`
` So
`
`So
`o N
`i)
`ie)
`
`yy
`.
`0
`oly
`
`
`
`Q401Q404GATE
`
`
`
`Q402Q403GATE
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 6 of 23 PageID #: 24
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 6 of 23 PagelD #: 24
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 4 of 11
`
`US 9,906,067 B1
`
`“540
`
`TIME
`
`FIG.6
`
`
`
` LSIN/A
`
`
`
`Q4010404GATE
`
`Q402Q403GATE
`
`
`
`Q405Q408GATE
`
`
`
`Q406Q407GATE
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 7 of 23 PageID #: 25
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 7 of 23 PagelD #: 25
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 5 of 11
`
`US 9,906,067 B1
`
`oel~”
`
`
`0Zl~”LeOf_LEEv900ZoHDom©=——<—MEMLfv920xLov
`SWIL0 vid|
`
`ZLOld
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 8 of 23 PageID #: 26
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 8 of 23 PagelD #: 26
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 6 of 11
`
`US 9,906,067 B1
`
`—
`
`~
`V401L
`
`|
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 9 of 23 PageID #: 27
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 9 of 23 PagelD #: 27
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 7 of 11
`
`US 9,906,067 B1
`
`«7910
`
`«”920
`
`a”930
`
`“940
`
`FIG.9
`
`TIME
`
`
`
`Q401Q404GATE
`
`Q402Q403GATE
`
`0 2 4 6 8
`
`V_C911/V
`
`10
`
`25 20 15 10
`
`-10 -15
`
`-20 -25
`
`5
`
`5
`
`ip/Ag
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 10 of 23 PageID #: 28
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 10 of 23 PagelD #: 28
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 8 of 11
`
`US 9,906,067 B1
`
`peeeeeeeeee0Z
`
`SVOvceo¢G202SlOlS0 O€017”ch
`
`
`
`SoESw/SWI
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 11 of 23 PageID #: 29
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 11 of 23 PagelD #: 29
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 9 of 11
`
`US 9,906,067 B1
`
`
`
`
`a7 1115
`1110
`
`FIG. 11
`
`410
`
`
`
`FIG. 12A
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 12 of 23 PageID #: 30
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 12 of 23 PagelD #: 30
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 10 of 11
`
`US 9,906,067 B1
`
`1230
`1230
`
`
`125012404920\ 1225/ 122012401250 4907
`
`¢
`
`FIG. 12B
`
`1330 DO 4340
`
`1320
`
`1380
`
`FIG. 13
`
`1410
`
`1440-<S 1430
`
`1420
`
`FIG. 14
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 13 of 23 PageID #: 31
`
`U.S. Patent
`
`Feb. 27, 2018
`
`Sheet 11 of 11
`
`US 9,906,067 B1
`
`
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 14 of 23 PageID #: 32
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 14 of 23 PagelD #: 32
`
`US 9,906,067 B1
`
`1
`APPARATUS, SYSTEM AND METHOD TO
`WIRELESSLY CHARGE/DISCHARGE A
`BATTERY
`
`TECHNICAL FIELD
`
`The present invention is directed, in general, to wireless
`power transmission and, more specifically, to an apparatus,
`system and method to wirelessly charge and/or discharge a
`battery.
`
`BACKGROUND
`
`A consideration in the design of consumer products is the
`use of a rechargeable battery to provide adequate,reliable,
`and unconstrained power to a consumer device. Up until
`about 20 years ago, most electrically powered consumer
`devices were simply coupled to the utility power grid.
`Rechargeable batteries saw limited use becauseearlier bat-
`tery technology allowed only a very limited number of
`charging cycles with limited charging efficiency.
`With the adoption of lithtum-basedbatteries that allow for
`a large number of charge/discharge cycles, rechargeable
`batteries began to see increasing use for consumerelectron-
`ics applications, facilitating the proliferation of electronic
`devices withouttethering to the utility grid. Despite the great
`advantage of allowing consumersto use electronic devices
`such as cellular phones, tablets, and laptop computers, the
`battery operated electronic devices still needed to be con-
`nected to the utility grid to recharge the batteries.
`In recent years, wireless power systems have been devel-
`oped that allow recharging of the batteries without making
`a physical connection between the battery and the charger.
`The wireless power systems use resonant operation to trans-
`fer power from a charger to a battery. The battery itself is
`electrically/metallically tied to the load it will eventually
`powerand charging is accomplished through a metallically
`isolated wireless interface. There are many reasonsthat the
`battery has been electrically/metallically tied to the load it
`operates including that both powertransfer and communi-
`cation in standard wireless interfaces is set up to allow
`transfer of power in only one direction. Additionally, stan-
`dard wireless power interfaces are inefficient, so too much
`battery life would be lost by driving an electronic device
`through a wireless interface.
`Standard wireless interfaces also require post regulators
`such as linear regulators because the control loop through a
`wireless interface is too slow for the wireless battery inter-
`face to adequately regulate the output of the battery. This
`regulator presents a further impedimentto processing power
`in both directions. Wireless interfaces also tend to be very
`limited in power, both because of poor coupling efficiency
`and because of the heat generated by the poor coupling for
`any appreciable levels of power. The poor coupling effi-
`ciency of wireless power systems also producesa loss in the
`voltage that can be produced by a system component, which
`causes a mismatch in the voltage that could be wirelessly
`produced by the battery compared with the voltage neces-
`sary to wirelessly charge the battery.
`There are many advantages associated with a battery that
`can be wirelessly charged or discharged, that is, one which
`interfaces wirelessly over a metallically isolated path for
`both charging and discharging. What is needed in the art,
`therefore,
`is a power system that can wirelessly charge a
`battery that overcomesthe deficiencies in the priorart.
`
`SUMMARY OF THE INVENTION
`
`These and other problemsare generally solved or circum-
`vented, and technical advantages are generally achieved, by
`
`10
`
`15
`
`20
`
`25
`
`35
`
`40
`
`45
`
`55
`
`60
`
`65
`
`2
`advantageous embodimentsof the present invention, includ-
`ing an apparatus, system and method to wirelessly charge
`and/or discharge a battery. In one embodiment, the apparatus
`includes a removable first magnetic core piecepart having a
`surroundingfirst metallic coil and configured to be coupled
`to and aligned with a second magnetic core piecepart having
`a surrounding second metallic coil to form a transformer.
`The apparatus also includesa battery metallically coupled to
`the first metallic coil and configured to be charged and
`discharged through an electrically isolating path of the
`transformer.
`
`The foregoing has outlined rather broadly the features and
`technical advantages of the present invention in order that
`the detailed description of the invention that follows may be
`better understood. Additional features and advantages of the
`invention will be described hereinafter, which form the
`subject of the claims of the invention. It should be appre-
`ciated by those skilled in the art that the conception and
`specific embodiment disclosed may be readily utilized as a
`basis for modifying or designing other structures or pro-
`cesses for carrying out the same purposes of the present
`invention. It should also be realized by those skilled in the
`art that such equivalent constructions do not depart from the
`spirit and scope of the invention as set forth in the appended
`claims.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`For a more complete understanding of the present inven-
`tion, reference is now made to the following descriptions
`taken in conjunction with the accompanying drawings, in
`which:
`
`FIG.1 illustrates a block diagram of an embodimentof a
`power system with a wireless battery interface and a wire-
`less battery;
`FIG.2 illustrates a schematic diagram of an embodiment
`of a power system with a wireless battery and a wireless
`battery interface;
`FIGS. 3 and 4 illustrate schematic diagrams of embodi-
`ments of a model of the transformer of FIG. 2;
`FIGS. 5 and 6 illustrate graphical representations of
`waveforms demonstrating an embodiment of a de trans-
`former modeof operation of the power system of FIG.2;
`FIG.7 illustrates a graphical representation of waveforms
`demonstrating an embodimentof a boost modeof operation
`of the power system of FIG. 2;
`FIG.8 illustrates a schematic diagram of an embodiment
`of a power system with a wireless battery and a wireless
`battery interface;
`FIG.9 illustrates a graphical representation of waveforms
`demonstrating an embodimentof an operation of the power
`system of FIG.8;
`FIG. 10 illustrates a graphical representation of wave-
`forms demonstrating an embodiment of a boost mode of
`operation of the power system of FIG. 8;
`FIG. 11 illustrates a diagram of an embodiment of a
`magnetic device;
`FIGS. 12A and 12B illustrate horizontal and vertical
`
`cross-sectional views, respectively, of an embodiment of a
`permanent magnetaligner;
`FIG. 13 illustrates a plan view of an embodiment of a
`permanent magnetaligner;
`FIG. 14 illustrates a diagram of an embodiment of a
`portion of a magnetic device;
`FIG. 15 illustrates a diagram of another embodimentof a
`portion of a magnetic device; and
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 15 of 23 PageID #: 33
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 15 of 23 PagelD #: 33
`
`US 9,906,067 B1
`
`3
`FIG. 16 illustrates a diagram of another embodimentof a
`portion of a magnetic device.
`Corresponding numerals and symbols in the different
`FIGUREs generally refer to corresponding parts unless
`otherwise indicated, and may not be redescribed in the
`interest of brevity after the first instance. The FIGUREsare
`drawn to illustrate the relevant aspects of exemplary
`embodiments.
`
`DETAILED DESCRIPTION OF ILLUSTRATIVE
`EMBODIMENTS
`
`The making and using of the present exemplary embodi-
`ments are discussed in detail below. It should be appreciated,
`however, that the present invention provides many appli-
`cable inventive concepts that can be embodied in a wide
`variety of specific contexts. The specific embodiments dis-
`cussed are merely illustrative of specific ways to make and
`use the invention, and do not limit the scope of the invention.
`The present invention will be described with respect to
`exemplary embodiments in a specific context, namely, an
`apparatus, system and method to wirelessly charge and/or
`discharge a battery. The power system will be described as
`a switched-mode power supply or power converter. Any
`application that may benefit from a wireless battery charged
`and discharged by a wireless battery interface is well within
`the broad scopeofthe present invention. Additionally, while
`the principles of the present invention will be described with
`respect to electronic devices (also referred to as a “load’”)
`such as cell phones, tablets, and power tools, other appli-
`cations are well within the broad scope of the present
`invention.
`In the environment of a conventional charging system
`with a cordless power tool or other battery operated elec-
`tronic device, a battery is attached to low-voltage de elec-
`trical connector that is formed with two metallic contacts. A
`
`load(or the battery operated electronic device) is attached to
`the low-voltage de electrical connector that is formed with
`the two metallic (galvanic) contacts. A charger is connected
`to the utility grid and also to the low-voltage de electrical
`connector that contains the two metallic contacts. A battery
`is metallically connected to the charger to charge the battery.
`To use the battery with the load, the battery is removed from
`the charger and is then metallically coupled to the load.
`Removing the battery from one device(e.g., the charger) and
`connecting it
`to another device (e.g.,
`the load) requires
`breaking and then reconnecting metallic electrical contacts.
`The terms “metallic and “galvanic” generally refer to,
`withoutlimitation, an electrical connection between separate
`parts that is a wired or a contact that may includeelectrically
`conductive components such as semiconductor devices as
`well as current-conducting components suchas resistors and
`inductors. Such wired connections conduct a current that
`may exceed a safety limit in response to an applied voltage
`difference across the ends of the electrical connection.
`A battery-charging arrangementas set forth above allows
`a single rechargeable battery to be used by different battery
`operated electronic devices. A drawback of such a system is
`that the battery is configured with exposedelectrical metallic
`contacts. The metallic contacts present several limitations
`such as the battery-charging arrangementis limited to envi-
`ronments that will not corrode the contacts. If exposed to a
`conductor, the metallic contacts can create a short circuit
`across the battery that can generate a dangerous amount of
`heat as well as destroy the battery. Also, a voltage of the
`battery-charging arrangementis limited to low voltages to
`address safety issues. All battery operated electronic devices
`
`25
`
`40
`
`45
`
`4
`that interface with the battery must be designedto operate at
`the same voltage as the battery.
`In cases where the battery is removed from the charger
`and connected to a load for a large numberof cycles, the
`electrical contacts can wear and eventually degrade the
`connection. The limitations of such conventional battery-
`charging arrangements could be overcomeif the electrical
`metallic contacts were replaced with a system to transmit
`powerwirelessly.
`A disadvantage of the conventional wireless battery sys-
`tems is poor powertransfer efficiency. Another disadvantage
`is a slow feedback loop that necessitates the use of a post
`regulator such as a linear regulator. Still another disadvan-
`tageis the need to galvanically couple thebattery to the load,
`thus makingit difficult to remove the battery without break-
`ing a metallic electrical contact. A further disadvantage is
`that the powerflow to the battery is unidirectional, thatis,
`the battery can be wirelessly charged, but the discharge
`occurs through a directly wired electrical connection.
`In conventional battery charging arrangements using
`magnetic devices (e.g., a transformer), transmit and receive
`coils (or windings) of the transformer are coupled through a
`common flux path including air or other substance of
`equivalent magnetic permeability. This creates a substantial
`amountof loss due to poor magnetic flux coupling, and the
`resulting powertransfer efficiency of the conventional wire-
`less battery power system is typically only on the order of 50
`percent. The substantially poor magnetic flux coupling of the
`conventional wireless battery power system makes it diffi-
`cult to discharge the battery through a wireless path since the
`battery charging takes place at a much slower rate than
`discharging the battery into a load. The poor magnetic flux
`coupling further prevents voltage matching of the charging
`and discharging cycles. The conventional battery charging
`arrangements also prevents a bidirectional powerflow to and
`from the battery.
`The power system as introduced herein provides the
`safety advantages and voltage scaling of a wireless power
`system, while preserving the efficiency and bidirectional
`powerflow obtained by the metallic contact battery power
`systems. The power system set forth herein eliminates the
`metallic contacts, thereby avoiding the concern with the
`corrosion of standard battery contacts. The wireless inter-
`face can be customized for any voltage interface. This
`allows batteries with any amount of energy storage to be
`standardized to produce a same voltage. High-voltage bat-
`tery strings can be safely interfaced to other electronic
`devices. A single wireless battery can interface with many
`electronic devices that would traditionally require de volt-
`ages different from that of the battery string. The nonme-
`tallic power interface as described herein can efficiently
`transfer power for an electronic device in both directions to
`regulate an output characteristic (e.g., an output voltage),
`and obviate the need for a post regulator regardless of the
`direction of powertransfer.
`Turning now to FIG.1, illustrated is a block diagram of
`an embodiment of a power system (also referred to as a
`“system’’) with a wireless battery interface 120 and a wire-
`less battery 130. A power source/load 110 such as a utility
`grid power source or a power tool is electrically coupled
`(1.e., wired) to the wireless battery interface 120. The
`wireless battery 130 is docked into the wireless battery
`interface 120 by a coupler. The coupler links a magneticfield
`140 induced by a metallic coil (or winding) 150 surrounding
`a wireless battery interface magnetic core piecepart in the
`wireless battery interface 120 with a wireless battery mag-
`netic core piecepart
`in the wireless battery 130. When
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 16 of 23 PageID #: 34
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 16 of 23 PagelD #: 34
`
`US 9,906,067 B1
`
`6
`however, the air gaps can be kept quite small such as 3 or 4
`millimeters (‘mm’). It would be advantageous to maintain
`the air gaps to be smaller than about 1.5 times the square-
`root of the cross-sectional area of the magnetic core
`pieceparts 202, 252 to reduce(e.g., minimize) fringing of the
`magnetic flux. The magnetic core pieceparts 202, 252 with
`the corresponding metallic coils 201, 251 form a transformer
`of the power system.
`The power system illustrated in FIG. 2 demonstrates one
`of many waysthat the magnetic core pieceparts 202, 252 can
`be designed to create a flux path that passes through the
`metallic coils 201, 251. The metallic coil 251 is coupled to
`a resonant capacitor C402 and a full-bridge powertrain is
`formed with power switches Q401, Q402, Q403, Q404 and
`diodes D401, D402, D403, D404 in anti-parallel with each
`respective power switch. In other words, each diode D401,
`D402, D403, D404 is oriented in the samedirection as the
`body (intrinsic) diode of the corresponding power switch
`Q401, 0402, Q403, Q404. The addition of the diodes D401,
`D402, D403, D404 reduces the voltage drop across the
`corresponding power switch Q401, Q402, Q403, Q404 and
`allows for higher switching speeds for the powertrain. Of
`course, the diodes D401, D402, D403, D404 may be omitted
`if the body diodes of the power switch Q401, Q402, Q403,
`Q404 can perform the intended task with the desired per-
`formance.
`
`The full-bridge power train formed with the power
`switches Q401, Q402, Q403, Q404 is coupled to a capacitor
`C401 and terminals 257 including a positive terminal POS
`and a negative terminal NEG. The capacitor C401 filters
`high-frequency current to provide a steady voltage to or
`from the terminals 257. The terminals 257 can be connected
`to either a power source or a load depending on whether the
`battery V401 is charging or discharging, respectively. The
`power source may be, for example, a power converter that
`regulates voltage from a utility grid such as a power-factor
`corrected power converter. The power source may also be a
`battery or a de voltage source connected to a universal serial
`bus (“USB”) powerport. There are many possibilities for a
`load including, without limitation, a string of light-emitting
`diodes (“LEDs”), a battery, or a power converter that pushes
`power into or receives power from the utility grid. The
`terminals 257 may connect to a powersource or load within
`the sameenclosure as the wireless battery interface 250. For
`instance, a power converter may be located in the same
`enclosure as the wireless battery interface 250 and have
`electrical connections leading to an external load or power
`source. Of course, a portion of or all of the power source or
`load can be located external to the enclosure of the wireless
`
`5
`charging the wireless battery 130, a voltage is induced in a
`metallic coil (or winding) 160 surrounding the wireless
`battery magnetic core piecepart in the wireless battery 120
`by a voltage impressed across the terminals of the metallic
`coil 150 that surrounds the wireless battery interface mag-
`netic core piecepart in the wireless battery interface 120.
`When discharging the wireless battery 130, a voltage is
`induced in the metallic coil (or winding) 150 surrounding
`the wireless battery interface magnetic core piecepart in the
`wireless battery interface 120 by a voltage impressed across
`the terminals of the metallic coil 160 that surrounds the
`wireless battery magnetic core piecepart
`in the wireless
`battery 130. The power source/load 110 can be,for instance,
`a utility grid power source that is employed to charge the
`wireless battery 130, and also can be arranged to absorb
`energy from the wireless battery 130 for utility grid power
`source load-leveling purposes. It should be understood that
`the connection between the metallic coil 160 and battery will
`include components therebetween.
`Turning now to FIG.2,illustrated is a schematic diagram
`of an embodimentof a power system with a wireless battery
`200 and a wireless battery interface 250. The wireless
`battery 200 is formed with a metallic coil 201 surrounding
`a wireless battery magnetic core piecepart 202 that can be
`used to both transmit and receive power. The wireless
`battery magnetic core piecepart 202 is typically composed
`of, without limitation, a soft ferrite, powered iron, or some
`other ferromagnetic substance with high magnetic perme-
`ability.
`The metallic coil 201 is coupled to a resonant capacitor
`C403 and a full-bridge powertrain is formed with power
`switches (e.g., metal-oxide semiconductorfield-effect tran-
`sistors “MOSFETs”)) Q405, Q406, Q407, Q408 and diodes
`D405, D406, D407, D408 in anti-parallel with each respec-
`tive power switch. In other words, each diode D405, D406,
`D407, D408 is oriented in the same direction as the body
`(intrinsic) diode of the corresponding power switch Q405,
`Q406, Q407, Q408. The addition of the diodes D405, D406,
`D407, D408 reduces the voltage drop across the correspond-
`ing power switch Q405, 0406, Q407, Q408 and allows for
`higher switching speeds for the powertrain. Of course, the
`diodes D405, D406, D407, D408 may be omitted if the body
`diodes of the power switch Q405, Q406, Q407, Q408 can
`perform the intended task with the desired performance. The
`term “switch” generally refers to any active semiconductor
`device such as, without limitation, a MOSFET or bipolar
`transistor or a passively switched semiconductor device such
`as a diode.
`The full-bridge powertrain formed with power switches
`battery interface 250. Many implementationsare possible as
`Q405, 2406, Q407, Q408 is coupled to a capacitor C404 and
`would occur to one skilled in theart.
`a rechargeable battery (or battery) V401. The capacitor C404
`The powersystem illustrated in FIG. 2 can process power
`filters high-frequency current to provide a steady voltage to
`from the terminals 257 to the battery V401 or from the
`or from the battery V401. The capacitor C404 may not be
`neededin all applications because the battery V401 can also
`battery V401 to the terminals 257. If transmitting power
`55
`act asafilter.
`from the terminals 257 to the battery V401, the full-bridge
`The wireless battery interface 250 is formed with a
`powertrain formed with the power switches Q401, Q402,
`metallic coil 251 surrounding a wireless battery interface
`Q403, Q404 produces a pulsed voltage waveform to the
`magnetic core piecepart 252 that can be used to both
`resonant capacitor C402 and the metallic coil 251. The
`transmit and receive power. The wireless battery interface
`full-bridge power train is switched so that
`the power
`magnetic core piecepart 252 is typically constructed with a
`switches Q401, Q404 are simultaneously turmed on and off
`soft ferrite, powered iron, or some other ferromagnetic
`with a duty cycle slightly less than about 50 percent (such as
`substance. The magnetic core pieceparts 202, 252 link most
`45 to 49 percent). Also, the power switches Q402, Q403 are
`of the magnetic flux that passes between the metallic coils
`simultaneously turned on and off with a duty cycle slightly
`201, 251. There is a small air gap in the magnetic path
`less than 50 percent and 180 degrees out-of-phase with
`created by the magnetic core pieceparts 202, 252. The air
`respect to the power switches Q401, Q404. The duty cycle
`gap is typically due to the enclosures of the wireless battery
`of each power switch is slightly less than 50 percent to
`200 and the wireless battery interface 250. In practice,
`decrease a possibility of simultaneous conduction with an
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`60
`
`65
`
`

`

`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 17 of 23 PageID #: 35
`Case 2:20-cv-00269-JRG Document 1-1 Filed 08/17/20 Page 17 of 23 PagelD #: 35
`
`US 9,906,067 B1
`
`8
`two sides ofthe ideal transformer TX501 such thatthe ratio
`between the inductance of the inductors L501, L503 is N?.
`If the inductance of the inductor L501 is L,,
`then the
`inductance of the inductor L503 is N7L,. The capacitance
`values for the resonant capacitors C402, C403 should pref-
`erably be chosen to obtain the same ratio of impedance as
`the inductances for the inductors L501, L503. So, if the
`resonant capacitor C402 has a capacitance C,,
`then the
`resonant capacitor C403 should be chosen with a value
`C,/N?. The input to the transformer 320 has a voltage Vp
`across the input terminals and a current i, enters the top
`terminal. The output of the transformer 320 has voltage v,
`and currenti,.
`For the purposes of analysis only, the galvanic isolation
`barrier can be removed from the circuit in FIG. 3 resulting
`in the diagram of FIG. 4. In FIG. 4, a circuit block 420
`models a transformer andreplaces the transformer 320 from
`FIG.3. In FIG.4, the inductors L501, L502, and the resonant
`capacitor C402 are the same as the correspondingly num-
`bered componentsillustrated in FIG. 3. The inductor L503S
`and the resonant capacitor C403S have been appropriately
`scaled translated to the other side of the circuit block 420.
`Furthermore, the output voltage and current are scaled by the
`transformer turns ratio to Nv, and i,/N, respectively, as
`illustrated in FIG.4.
`
`With continuing reference to FIGS. 3 and 4, an advanta-
`geous mode of operation of the power system illustrated in
`FIG. 2 is a de transformer mode of operation. In the dc
`transformer mode of operation, the full-bridge power train
`on the transmitting side is driven at the resonant frequency
`of the resonant capacitor C402 and the inductor L501. The
`resonant frequency of the resonant capacitor C402 and the
`inductor L501 is:
`
`1—2
`
`nv CL,
`
`The resonant frequency of the inductor L503S and the
`resonant capacitor C403S is the sameas that of the resonant
`capacitor C402 and the inductor L501. As a result, when
`driving power switchesat the resonant frequency, the circuit
`block 420 of FIG. 4 can be simplified to a parallel inductor
`L,, with the voltage and current at the battery scaled by the
`factor N. The magnetic structure thus acts like a de trans-
`former in parallel with an inductor. Operating in de trans-
`former mode of operation is possible because the magnetic
`core pieceparts 202, 252 provide consistent and tight cou-
`pling between the metallic coils 201, 251 illustrated in FIG.
`2.
`
`In practice, the driving frequencyis usually slightly lower
`than the resonant frequency of the resonant capacitor C402
`and the inductor L501 because the diode bridge (the diodes
`D405, D406, D407, D408) of the wireless battery 200
`prevents the resonant current from continuing to flow after
`the current in the wireless battery 200 passes through zero,
`thereby allowing a window ofdriving frequency over which
`the power system will behavelike a de transformer. Thatis,
`the voltages v,=Nv, for a small range of frequenciesare at
`and above the resonant frequency. The ratio of output
`voltage to input voltage is independent of load current and
`remainsa fixed ratio that is the same as the ratio of turns in
`
`the metallic coils 201, 251. The resonant capacitors C402,
`C403 can thus be selected to produce substantially zero-
`current switching of a switching circuit of the powertrain in
`conjunction with at least one inductor (e.g., an inductor
`
`7
`opposing power switch and to allow enough time for a
`magnetizing current in the metallic coil 251 to resonate with
`the parasitic capacitance of the power switches Q401, Q402,
`Q403, Q404 to commutate a voltage thereacross. This pro-
`cess results in soft-switching, meaning the voltage across or
`the current through each power switch Q401, Q402, Q403,
`Q404is naturally resonated to substantially zero just prior to
`turning that respective power switch on oroff.
`For cases in which the wireless battery interface 250 is
`used as a battery charger, it is also possible to configure a
`controller X401 to turn off the power switch Q403 and turn
`on the power switch Q404 continuously. As a result, the
`full-bridge power train formed with the power switches
`Q401, 2402, Q403, Q404 will act as a half-bridge power
`train with the resonant capacitor C402 absorbing a de offset
`caused by half-bridge operation. Reverting from a full-
`bridge to a half-bridge power train may be useful, for
`example, when a charging circuit connected to the terminals
`257 switches connection from a 115 Vac utility grid power
`source to a 230 Vac utility grid power source since a
`half-bridge configuration will transmit only half as much
`voltage as a full-bridge configuration. The controller X401
`can therefore be configured to selectively cause at least a
`portion of the powertrain to switch between full-bridge and
`half-bridge operation in response to a sensed voltage level
`(e.g., the voltage at the terminals 257).
`A pulsed voltage that appears across the metallic coil 251
`induces a voltage across the metallic coil 201 that is scaled
`by a transformer turns ratio of the metallic coils 201, 251.
`The voltage across the metallic coil 201 appears across the
`resonant capacitor C403 in series with the full-bridge power
`train formed with the power switches Q405, Q406, Q407,
`Q408. The diodes D405, D406, D407, D408 rectify the
`pulsed voltage that appears across the metallic coil 201 and
`the resonant capacitor C403 andthe resulting poweris sent
`to the battery V401. The powerswitches Q405, 0406, Q407,
`Q408 may be turned on during someorall of the time that
`the corresponding diodes D405, D406, D407, D408 are
`conducting to reduce conduction losses therein.
`If the power system illustrated in FIG. 2 transmits power
`from the battery V401 to the terminals 257, the process as
`described above is reversed. That
`is, a controller X402
`drives the full-bridge power train formed with the power
`switches Q405, Q406, Q407, Q408 to produce a pulsed
`voltage across the resonant capacitor C403 and the metallic
`coil 201. The induced voltage in the metallic coil 251 is then
`rectified by the diodes D401, D402, D403, D404 to send
`power to the terminals 257. Accordingly,
`the resonant
`capacitors C402, C403 in conjunction with the metallic coils
`201, 251 and the full-bridge powertrains form a resonant
`topology.
`Turing now to FIGS. 3 and4, illustrated are schematic
`diagrams of embodiments of a model of the transformer of
`FIG. 2. The magnetic core pieceparts 202, 252 with corre-
`spo