U.S. patent application number 15/878378 was filed with the patent office on 2018-06-21 for proximity wireless power system using a bidirectional power converter.
This patent application is currently assigned to Enovate Medical LLC. The applicant listed for this patent is Enovate Medical, LLC. Invention is credited to George Blakely, Gordon Waid.
Application Number | 20180175673 15/878378 |
Document ID | / |
Family ID | 57587146 |
Filed Date | 2018-06-21 |
United States Patent
Application |
20180175673 |
Kind Code |
A1 |
Blakely; George ; et
al. |
June 21, 2018 |
PROXIMITY WIRELESS POWER SYSTEM USING A BIDIRECTIONAL POWER
CONVERTER
Abstract
A bidirectional power converter circuit is controlled via a
hysteresis loop such that the bidirectional power converter circuit
can compensate in near real time for variations and even changes in
transmit and receive coil locations without damaging components of
the system. Because the bidirectional power converter is capable of
both transmitting and receiving power (at different times), one
circuit and board may be used as the main component in multiple
wireless power converter designs. The bidirectional power converter
circuit is used in a proximity wireless power transmitter and a
proximity wireless power receiver, such that the transmitter and
receiver may be misaligned in any direction while providing power
from the transmitter to the receiver without damaging any circuitry
of either the bidirectional power converter transmitter or the
bidirectional power converter receiver.
Inventors: |
Blakely; George;
(Murfreesboro, TN) ; Waid; Gordon; (Murfreesboro,
TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Enovate Medical, LLC |
Murfreesboro |
TN |
US |
|
|
Assignee: |
Enovate Medical LLC
Murfreesboro
TN
|
Family ID: |
57587146 |
Appl. No.: |
15/878378 |
Filed: |
January 23, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15096242 |
Apr 11, 2016 |
9887577 |
|
|
15878378 |
|
|
|
|
62146091 |
Apr 10, 2015 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J 50/90 20160201;
H02J 50/80 20160201; H02J 50/12 20160201; H02J 50/10 20160201; H02M
7/797 20130101; H02J 7/025 20130101; H02J 50/20 20160201; H02J
7/045 20130101; H04B 1/40 20130101; H02J 7/04 20130101; H04B 1/16
20130101; H02M 7/5383 20130101; H02J 7/007192 20200101; H02J
7/00714 20200101; H02M 7/70 20130101; H02M 1/08 20130101 |
International
Class: |
H02J 50/12 20060101
H02J050/12; H02J 50/90 20060101 H02J050/90 |
Claims
1. A proximity wireless power transfer system comprising: a
proximity wireless power transmitter operable to periodically test
for the presence of a proximity wireless power receiver and provide
power to the proximity wireless power receiver when within range of
the proximity wireless power transmitter, said proximity wireless
power transmitter comprising: a bidirectional power converter
operable to provide alternating current (AC) power at an AC
terminal of the bidirectional power converter when in a transmit
mode of the bidirectional power converter and enabled via a
transmitter enable signal or a hysteresis control signal; a direct
current (DC) power source configured to provide power to a DC input
terminal of the bidirectional power converter and a directional
control signal to a direction control input of the bidirectional
power converter, wherein the directional control signal indicates a
transmit mode of the bidirectional power converter; a tuning
capacitor; a wire coil connected in series with the tuning
capacitor to the AC terminal of bidirectional power converter,
wherein the wire coil is configured to receive the AC output signal
from the bidirectional power converter and emit a corresponding
electromagnetic field; an automatic turn on assembly configured to
provide the transmitter enable signal to the bidirectional power
converter, wherein the automatic turn on assembly, when enabled, is
configured to selectively enable and disable the bidirectional
power converter via the transmitter enable signal; a voltage detect
circuit configured to determine a voltage across the tuning
capacitor and reset the automatic turn on assembly whenever the
voltage across the tuning capacitor exceeds a predetermined
threshold, wherein the automatic turn on assembly disables the
bidirectional power converter for a predetermined period of time
via the transmitter enable signal when the automatic turn on
assembly is reset; and a radio frequency (RF) receiver configured
to receive a radio frequency signal from an RF transmitter of a
cart bidirectional power converter receiver receiving power from
the proximity wireless power transmitter and provide the hysteresis
control signal to the bidirectional power converter as a function
of the received radio frequency signal.
2. The proximity wireless power transfer system of claim 1, wherein
the RF receiver of the proximity wireless power transmitter and the
RF transmitter of the cart bidirectional power converter receiver
operate at approximately 433 MHz.
3. The proximity wireless power transfer system of claim 1, further
comprising the cart bidirectional power converter receiver.
4. The proximity wireless power transfer system of claim 1, further
comprising the cart bidirectional power converter receiver, wherein
the cart bidirectional wireless power transceiver is configured to
provide the RF signal as a function of a DC voltage of a DC output
terminal of the cart bidirectional power converter.
5. The proximity wireless power transfer system of claim 1, further
comprising the cart bidirectional power converter receiver, wherein
the cart bidirectional wireless power transceiver is configured to
provide the RF signal as a function of a DC voltage of a DC output
terminal of the cart bidirectional power converter, wherein the RF
signal carries a binary zero when the DC voltage at the DC output
terminal of the cart bidirectional power converter is above a
predetermined threshold and a binary one when the DC voltage at the
DC output terminal is less than the predetermined threshold.
6. The proximity wireless power transfer system of claim 1, further
comprising the cart bidirectional power converter receiver, wherein
the cart bidirectional wireless power receiver is configured to
provide the RF signal as a function of a DC voltage of a DC output
terminal of the cart bidirectional power converter, wherein the RF
signal carries a binary zero when the DC voltage at the DC output
terminal of the cart bidirectional power converter is above a first
predetermined threshold and a binary one when the DC voltage at the
DC output terminal is less than a second predetermined
threshold.
7. The proximity wireless power transfer system of claim 1, wherein
the bidirectional power converter of the proximity wireless
transmitter comprises: an oscillator configured to provide a drive
signal at a base frequency when the bidirectional power converter
is operating in the transmit mode; an amplifier configured to
receive power from the DC power source via the DC input terminal of
the bidirectional power converter and provide an AC output signal
to the AC terminal of the bidirectional power converter in response
to receiving the drive signal when the bidirectional power
converter is operating in the transmit mode; a modulator configured
to selectively provide the drive signal from the oscillator to the
amplifier as a function of a hysteretic control signal when the
bidirectional power converter is operating in the transmit mode; a
hysteretic receiver circuit configured to receive a transmitted
control signal at the bidirectional power converter and provide the
hysteretic control signal to the modulator as a function of the
received, transmitted control signal when the bidirectional power
converter is operating in the transmit mode, wherein the hysteretic
receiver circuit comprises the RF receiver; a transmit relay
configured to electrically connect the amplifier to the AC terminal
of the bidirectional power converter when the bidirectional power
converter is operating in the transmit mode and electrically
disconnect the amplifier from the AC terminal of the bidirectional
power converter when the bidirectional power converter is operating
in the receive mode; a rectifier configured to receive an
alternating current power signal from the AC terminal of the
bidirectional power converter and provide a DC output to the DC
output terminal of the bidirectional power converter when the
bidirectional power converter is operating in the receive mode; a
receive relay configured to enable the rectifier to provide the DC
output to the DC output terminal of the bidirectional power
converter when the bidirectional power converter is operating in
the receive mode and prevent the rectifier from providing the DC
output to the DC output terminal when the bidirectional power
converter is operating in the transmit mode; and a hysteretic
control circuit configured to monitor the DC output and transmit a
control signal as a function of the monitored DC output when the
bidirectional power converter is operating in the receive mode.
10. The proximity wireless power transfer system of claim 7,
wherein the modulator is an amplitude shift keyed modulator.
11. The proximity wireless power transfer system of claim 7,
wherein the amplifier is a full bridge amplifier.
12. The proximity wireless power transfer system of claim 7,
wherein the rectifier is a full wave rectifier.
13. The proximity wireless power transfer system of claim 7,
wherein the base frequency of the oscillator is approximately 100
kHz.
14. The proximity wireless power transfer system of claim 7,
wherein the bidirectional power converter further comprises: a slow
start circuit configured to provide a pulse width modulated signal
that increases from zero to one hundred percent duty cycle
beginning when the bidirectional power converter begins operating
in the transmit mode, wherein the rate of increase is generally
linear; and a one shot timer configured to provide a one shot
signal to the modulator when the bidirectional power converter
begins operating in the transmit mode and for a predetermined
period of time thereafter, wherein: the modulator is further
configured to provide the drive signal from the oscillator to the
amplifier when the pulse width modulated signal is on and at least
one of the hysteretic control signal and one shot signal are
on.
15. The proximity wireless power transfer system of claim 7,
wherein the bidirectional power converter further comprises: a
switching regulator configured to generate bias voltages when the
bidirectional power converter is receiving power from the DC power
source at the DC input terminal of the bidirectional power
converter, wherein the switching regulator provides at least one of
the generated bias voltages to: the oscillator, the amplifier, the
modulator, the hysteretic receiver circuit, and the transmit relay,
and a slow start circuit, a one shot timer, and a temperature
sensor of the bidirectional power converter.
16. The bidirectional power converter of claim 1, further
comprising: a temperature sensor configured to monitor a
temperature of the amplifier and provide a temperature sensing
signal; and a control logic configured to provide a modulator
enable signal to the modulator as a function of the temperature
sensing signal and the transmitter enable signal such that the
modulator enable signal is provided when the direction control
signal sets the bidirectional power converter in the transmit mode,
the transmitter enable signal is enabling the bidirectional power
converter, and the temperature sensing signal is indicative of a
temperature less than a predetermined temperature, wherein the
modulator does not provide the drive signal from the oscillator to
the amplifier when the modulator is not receiving the modulator
enable signal.
Description
[0001] A portion of the disclosure of this patent document contains
material that is subject to copyright protection. The copyright
owner has no objection to the reproduction of the patent document
or the patent disclosure, as it appears in the U.S. Patent and
Trademark Office patent file or records, but otherwise reserves all
copyright rights whatsoever.
CROSS-REFERENCES TO RELATED APPLICATIONS
[0002] 100021 This application is a continuation of U.S. patent
application Ser. No. 15/096,242 entitled Proximity Wireless Power
System Using a Bidirectional Power Converter, filed Apr. 11, 2016,
which claims priority to, and hereby incorporates by reference in
its entirety, U.S. Provisional Patent Application Ser. No.
62/146,091 entitled "WIRELESS POWER SYSTEM" filed on Apr. 10,
2015.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] Not Applicable
REFERENCE TO SEQUENCE LISTING OR COMPUTER PROGRAM LISTING
APPENDIX
[0004] Not Applicable
BACKGROUND OF THE INVENTION
[0005] The present invention relates generally to power converters.
More particularly, this invention pertains to bidirectional power
converters and wireless power transfer systems.
[0006] Designing circuits and laying out printed circuit boards is
a time consuming and expensive process. Further, having multiple
circuits and boards requires tracking multiple revisions of
multiple circuits and printed circuit boards, which adds layers of
complexity. However, in current power transfer circuit design
techniques, circuit and board layouts are created for one specific
purpose. Having multiple circuits and board layouts, each with
multiple revisions is therefore heretofore unavoidable.
[0007] Wireless charging systems are limited by, inter alia, size,
space, and transmitter/receiver orientation limitations. That is,
wireless charging systems for batteries have wireless chargers, but
the batteries directly physically contact the circuits of the
device powered by the battery. The battery is not fully wireless
which can be advantageous in wet or sterile environments. Further,
wireless charging systems are currently limited by distance and/or
orientation. That is, in some systems a transmitter coil must
nearly be in contact with a receiver coil (e.g., laying a cell
phone equipped with wireless charging capabilities on a wireless
charging pad). In these systems, the Z directional differential
between the transmitter coil and the receiver coil is therefore
near zero while the X and Y directional variations are within a
margin of error (e.g., the cell phone and its power receiving coil
are within a specified diameter of a transmitting coil or antenna
of the charging pad). In other systems, the Z directional
differential between the transmitter coil and the receiver coil may
be substantial, but the transmitter coil and the receiver coil must
be located on the same axis (i.e., almost no variation in the X and
Y directions between the coils and no variation in pitch). If the
pitch or X-Y translation is not accurate, the transmitter may be
damaged, requiring replacement of the transmitter circuit board.
Thus, wireless charging systems that cannot compensate for
variations in transmitter and receiver coil relative locations are
difficult to manage and repair, and they are not practical for many
uses in the field.
BRIEF SUMMARY OF THE INVENTION
[0008] Aspects of the present invention provide a bidirectional
power converter circuit. The bidirectional power converter circuit
is controlled via a hysteresis loop such that the bidirectional
power converter circuit can compensate in near real time for
variations and even changes in transmit and receive coil locations
without damaging any components of the system. Further, because the
bidirectional power converter is capable of both transmitting and
receiving power (at different times), one circuit and board may be
used as the main component in multiple wireless power converter
designs.
[0009] In one aspect, a proximity wireless power transfer system
includes a proximity wireless power transmitter. The proximity
wireless power transmitter is operable to periodically test for the
presence of a proximity wireless power receiver and provide power
to the proximity wireless power receiver when within range of the
proximity wireless power transmitter. The proximity wireless power
transmitter includes a bidirectional power converter, a DC power
source, a tuning capacitor, a wire coil, an automatic turn on
assembly, a voltage detection circuit, and a radiofrequency
receiver. The bidirectional power converter is operable to provide
an alternating current (AC) power at an AC terminal of the
bidirectional power converter when in a transmit mode of the
bidirectional power converter and enabled via a transmitter enable
signal or a hysteresis control signal. The direct current (DC)
power source is configured to provide power to a DC input terminal
of the bidirectional power converter and a directional control
signal to a direction control input of the bidirectional power
converter. The directional control signal indicates a transmit mode
of the bidirectional power converter. The wire coil is connected in
series with the tuning capacitor to the AC terminal of the
bidirectional power converter. The wire coil is configured to
receive the AC output signal from the amplifier and emit a
corresponding electromagnetic field. The automatic turn on assembly
is configured to provide the transmitter enable signal to the
bidirectional power converter, and the automatic turn on assembly,
when enabled, is configured to selectively enable and disable the
bidirectional power converter via the transmitter enable signal.
The voltage detect circuit is configured to determine a voltage
across the tuning capacitor and reset the automatic turn on
assembly whenever the voltage across the tuning capacitor exceeds a
predetermined threshold. The automatic turn on assembly disables
the bidirectional power converter for a predetermined period of
time via the transmitter enable signal when the automatic turn on
assembly is reset. The radiofrequency (RF) receiver is configured
to receive the radiofrequency signal from an RF transmitter of a
cart bidirectional power converter receiver receiving power from
the proximity wireless power transmitter. The radiofrequency
receiver provides the hysteresis control signal to the
bidirectional power converter as a function of the received
radiofrequency signal.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] FIG. 1 is a block diagram of how FIGS. 1A to 1I fit together
to form a block diagram of one embodiment of a bidirectional power
converter.
[0011] FIG. 1A is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1.
[0012] FIG. 1B is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1.
[0013] FIG. 1C is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1.
[0014] FIG. 1D is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1
[0015] FIG. 1E is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1.
[0016] FIG. 1F is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1.
[0017] FIG. 1G is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1.
[0018] FIG. 1H is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1.
[0019] FIG. 1I is a partial block diagram of the block diagram of
the bidirectional power converter of FIG. 1.
[0020] FIG. 2 is a block diagram of how FIG. 2A to FIG. 2P fit
together to form a partial schematic diagram of the bidirectional
power converter of FIG. 1.
[0021] FIG. 2A is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0022] FIG. 2B is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0023] FIG. 2C is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0024] FIG. 2D is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0025] FIG. 2E is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0026] FIG. 2F is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0027] FIG. 2G is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0028] FIG. 2H is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0029] FIG. 2I is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0030] FIG. 2J is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0031] FIG. 2K is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0032] FIG. 2L is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0033] FIG. 2M is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0034] FIG. 2N is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0035] FIG. 2O is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0036] FIG. 2P is a partial schematic diagram of the bidirectional
power converter of FIG. 2.
[0037] FIG. 3 is a block diagram of how FIGS. 3A to 3V fit together
to form a partial schematic diagram of the bidirectional power
converter of FIGS. 1 and 2.
[0038] FIG. 3A is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0039] FIG. 3B is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0040] FIG. 3C is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0041] FIG. 3D is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0042] FIG. 3E is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0043] FIG. 3F is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0044] FIG. 3G is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0045] FIG. 3H is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0046] FIG. 3I is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0047] FIG. 3J is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0048] FIG. 3K is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0049] FIG. 3L is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0050] FIG. 3M is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0051] FIG. 3N is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0052] FIG. 3O is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0053] FIG. 3P is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0054] FIG. 3Q is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0055] FIG. 3R is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0056] FIG. 3S is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0057] FIG. 3T is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0058] FIG. 3U is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0059] FIG. 3V is a partial schematic diagram of the bidirectional
power converter of FIG. 3.
[0060] FIG. 4 is a block diagram of how FIG. 4A to FIG. 4Z fit
together to form a partial schematic diagram of the bidirectional
power converter of FIGS. 1, 2, and 3.
[0061] FIG. 4A is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0062] FIG. 4B is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0063] FIG. 4C is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0064] FIG. 4D is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0065] FIG. 4E is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0066] FIG. 4F is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0067] FIG. 4G is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0068] FIG. 4H is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0069] FIG. 4I is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0070] FIG. 4J is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0071] FIG. 4K is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0072] FIG. 4L is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0073] FIG. 4M is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0074] FIG. 4N is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0075] FIG. 4O is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0076] FIG. 4P is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0077] FIG. 4Q is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0078] FIG. 4R is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0079] FIG. 4S is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0080] FIG. 4T is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0081] FIG. 4U is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0082] FIG. 4V is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0083] FIG. 4 W is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0084] FIG. 4X is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0085] FIG. 4Y is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0086] FIG. 4Z is a partial schematic diagram of the bidirectional
power converter of FIG. 4.
[0087] FIG. 5 is a block diagram of how FIG. 5A to FIG. 5J fit
together to form a partial schematic diagram of the bidirectional
power converter of FIGS. 1-4.
[0088] FIG. 5A is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0089] FIG. 5B is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0090] FIG. 5C is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0091] FIG. 5D is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0092] FIG. 5E is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0093] FIG. 5F is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0094] FIG. 5G is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0095] FIG. 5H is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0096] FIG. 5I is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0097] FIG. 5J is a partial schematic diagram of the bidirectional
power converter of FIG. 5.
[0098] FIG. 6 is a block diagram of how FIGS. 6A to 6U fit together
to form a proximity wireless power system employing bidirectional
power converters in a proximity wireless power transmitter and a
proximity wireless power receiver.
[0099] FIG. 6A is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0100] FIG. 6B is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0101] FIG. 6C is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0102] FIG. 6D is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0103] FIG. 6E is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0104] FIG. 6F is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0105] FIG. 6G is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0106] FIG. 6H is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0107] FIG. 6I is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0108] FIG. 6J is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0109] FIG. 6K is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0110] FIG. 6L is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0111] FIG. 6M is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0112] FIG. 6N is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0113] FIG. 6O is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0114] FIG. 6P is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0115] FIG. 6Q is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0116] FIG. 6R is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0117] FIG. 6S is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0118] FIG. 6T is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0119] FIG. 6U is a partial proximity wireless power system
employing bidirectional power converters in a proximity wireless
power transmitter and a proximity wireless power receiver of FIG.
6.
[0120] FIG. 7 is a block diagram of how to fit together to form a
partial schematic diagram of the proximity wireless power
transmitter of FIG. 6 including an RF receiving circuit and pulse
conditioning circuit.
[0121] FIG. 8 is a block diagram of how FIGS. 8A to 8D fit together
to form a partial schematic diagram of the proximity wireless power
transmitter of FIG. 6 including an over voltage detection
circuit.
[0122] FIG. 8A is a partial schematic diagram of the proximity
wireless power transmitter of FIG. 6 including an over voltage
detection circuit of FIG. 8.
[0123] FIG. 8B is a partial schematic diagram of the proximity
wireless power transmitter of FIG. 6 including an over voltage
detection circuit of FIG. 8.
[0124] FIG. 8C is a partial schematic diagram of the proximity
wireless power transmitter of FIG. 6 including an over voltage
detection circuit of FIG. 8.
[0125] FIG. 8D is a partial schematic diagram of the proximity
wireless power transmitter of FIG. 6 including an over voltage
detection circuit of FIG. 8.
[0126] FIG. 9 is a block diagram of how FIGS. 9A to 9J fit together
to form a partial schematic diagram of the proximity wireless power
transmitter of FIG. 6 including an automatic turn on assembly.
[0127] FIG. 9A is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0128] FIG. 9B is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0129] FIG. 9C is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0130] FIG. 9D is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0131] FIG. 9E is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0132] FIG. 9F is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0133] FIG. 9G is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0134] FIG. 9H is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0135] FIG. 9I is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0136] FIG. 9J is a partial schematic diagram of the proximity of
wireless power transmitter of FIG. 6 including an automatic turn on
assembly of FIG. 9.
[0137] FIG. 10 is a block diagram of how FIGS. 10A to 10E fit
together to form a partial schematic diagram of a voltage detecting
circuit of the proximity wireless power transmitter of FIG. 6.
[0138] FIG. 10A is a partial schematic diagram of a voltage
detecting circuit of the proximity wireless power transmitter of
FIG. 10.
[0139] FIG. 10B is a partial schematic diagram of a voltage
detecting circuit of the proximity wireless power transmitter of
FIG. 10.
[0140] FIG. 10C is a partial schematic diagram of a voltage
detecting circuit of the proximity wireless power transmitter of
FIG. 10.
[0141] FIG. 10D is a partial schematic diagram of a voltage
detecting circuit of the proximity wireless power transmitter of
FIG. 10.
[0142] FIG. 10E is a partial schematic diagram of a voltage
detecting circuit of the proximity wireless power transmitter of
FIG. 10.
[0143] FIG. 11 is a block diagram of how FIGS. 11A to 11H fits
together to form a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 6 and FIG. 7.
[0144] FIG. 11A is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 11.
[0145] FIG. 11B is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 11.
[0146] FIG. 11C is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 11.
[0147] FIG. 11D is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 11.
[0148] FIG. 11E is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 11.
[0149] FIG. 11F is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 11.
[0150] FIG. 11G is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 11.
[0151] FIG. 11H is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 11.
[0152] FIG. 12 is a block diagram of how FIGS. 12A to 12D fit
together to form a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 6 and FIG. 7.
[0153] FIG. 12A is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 12.
[0154] FIG. 12B is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 12.
[0155] FIG. 12C is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 12.
[0156] FIG. 12D is a partial schematic diagram of a pulse
conditioning circuit of the proximity wireless power transmitter of
FIG. 12.
[0157] FIG. 13 is a block diagram of how FIGS. 4A to 4H, 4J to 4O,
4Q to 4U, 4X to 4Z and 13I, 13P, 13V and 13W fit together to form a
partial schematic diagram of a transmitter of the proximity
wireless power receiver of FIG. 6.
[0158] FIG. 13I is a partial schematic diagram of a transmitter of
the proximity wireless power receiver of FIG. 13.
[0159] FIG. 13P is a partial schematic diagram of a transmitter of
the proximity wireless power receiver of FIG. 13.
[0160] FIG. 13V is a partial schematic diagram of a transmitter of
the proximity wireless power receiver of FIG. 13.
[0161] FIG. 13 W is a partial schematic diagram of a transmitter of
the proximity wireless power receiver of FIG. 13.
[0162] Reference will now be made in detail to optional embodiments
of the invention, examples of which are illustrated in accompanying
drawings. Whenever possible, the same reference numbers are used in
the drawing and in the description referring to the same or like
parts.
DETAILED DESCRIPTION OF THE INVENTION
[0163] While the making and using of various embodiments of the
present invention are discussed in detail below, it should be
appreciated that the present invention provides many applicable
inventive concepts that can be embodied in a wide variety of
specific contexts. The specific embodiments discussed herein are
merely illustrative of specific ways to make and use the invention
and do not delimit the scope of the invention.
[0164] To facilitate the understanding of the embodiments described
herein, a number of terms are defined below. The terms defined
herein have meanings as commonly understood by a person of ordinary
skill in the areas relevant to the present invention. Terms such as
"a," "an," and "the" are not intended to refer to only a singular
entity, but rather include the general class of which a specific
example may be used for illustration. The terminology herein is
used to describe specific embodiments of the invention, but their
usage does not delimit the invention, except as set forth in the
claims.
[0165] The phrase "in one embodiment," as used herein does not
necessarily refer to the same embodiment, although it may.
Conditional language used herein, such as, among others, "can,"
"might," "may," "e.g.," and the like, unless specifically stated
otherwise, or otherwise understood within the context as used, is
generally intended to convey that certain embodiments include,
while other embodiments do not include, certain features, elements
and/or states. Thus, such conditional language is not generally
intended to imply that features, elements and/or states are in any
way required for one or more embodiments or that one or more
embodiments necessarily include logic for deciding, with or without
author input or prompting, whether these features, elements and/or
states are included or are to be performed in any particular
embodiment.
[0166] The terms "coupled" and "connected" mean at least either a
direct electrical connection between the connected items or an
indirect connection through one or more passive or active
intermediary devices.
[0167] The term "circuit" means at least either a single component
or a multiplicity of components, either active and/or passive, that
are coupled together to provide a desired function.
[0168] The terms "switching element" and "switch" may be used
interchangeably and may refer herein to at least: a variety of
transistors as known in the art (including but not limited to FET,
BJT, IGBT, JFET, etc.), a switching diode, a silicon controlled
rectifier (SCR), a diode for alternating current (DIAC), a triode
for alternating current (TRIAC), a mechanical single pole/double
pole switch (SPDT), or electrical, solid state or reed relays.
Where either a field effect transistor (FET) or a bipolar junction
transistor (BJT) may be employed as an embodiment of a transistor,
the scope of the terms "gate," "drain," and "source" includes
"base," "collector," and "emitter," respectively, and
vice-versa.
[0169] The terms "power converter" and "converter" unless otherwise
defined with respect to a particular element may be used
interchangeably herein and with reference to at least DC-DC, DC-AC,
AC-DC, buck, buck-boost, boost, half-bridge, full-bridge, H-bridge
or various other forms of power conversion or inversion as known to
one of skill in the art.
[0170] As used herein, "micro" refers generally to any
semiconductor based microelectronic circuit including, but not
limited to, a comparator, an operational amplifier, a
microprocessor, a timer, an AND gate, a NOR gate, an OR gate, an
XOR gate, or a NAND gate.
[0171] Terms such as "providing," "processing," "supplying,"
"determining," "calculating" or the like may refer at least to an
action of a computer system, computer program, signal processor,
logic or alternative analog or digital electronic device that may
be transformative of signals represented as physical quantities,
whether automatically or manually initiated.
[0172] To the extent the claims recited herein recite forms of
signal transmission, those forms of signal transmission do not
encompass transitory forms of signal transmission.
[0173] Referring now to FIGS. 1-5, in one embodiment, a
bidirectional power converter 100 is operable to provide AC power
to an AC terminal 102 of the bidirectional power converter 100 in a
transmit mode of the bidirectional power converter 100. The
bidirectional power converter 100 is further operable to provide DC
power at a DC output terminal 104 of the bidirectional power
converter 100 in a receive mode of the bidirectional power
converter 100. In one embodiment, bidirectional power converter 100
includes an oscillator 106, an amplifier 108, a modulator 110, a
hysteretic receiver circuit 112, a transmit relay 114, a rectifier
116 a receive relay 118, and a hysteretic control circuit 120. In
one embodiment, the bidirectional power converter 100 includes two
generally independent sections, a transmitter section and a
receiver section. The transmitter section and the receiver section
are selectively connected to the DC output terminal 104 and AC
terminal 102 by a set of solid state relays (e.g., transmit relay
114 and receive relay 118).
[0174] The oscillator 106 is configured to provide a drive signal
at a base frequency when the bidirectional power converter 100 is
operating in the transmit mode. In one embodiment, the base
frequency of the oscillator 106 is approximately 100 kHz. In one
embodiment, the oscillator 106 generates the carrier frequency at
which power is transmitted by the bidirectional power converter
transmitter section. In one embodiment, micro U17 of oscillator 106
is an industry standard 556 timer which contains two 555 timers.
One timer of micro U17 is configured as a one shot timer, and the
other timer is a free running oscillator, oscillating at 100 KHz.
The one shot timer of micro U17 guarantees a 50% duty cycle for the
modulator 110 during startup of the transmitter section. Resistors
R65 and R70 as well as capacitors C47 and C49 set the free running
frequency of 100 kHz (or some other base frequency). Resistors R67
and R68 and capacitor C44 set the one shot timer for a precise 50%
duty cycle out of pin 9 of the micro U17.
[0175] The amplifier 108 is configured to receive power from a
power source via DC input terminal 122 of the bidirectional power
converter 100 and provide an AC output signal to the AC terminal
102 of the bidirectional power converter 100 in response to
receiving the drive signal when the bidirectional power converter
100 is operating in the transmit mode. In one embodiment, the
amplifier 108 is a full bridge amplifier. In one embodiment, the
amplifier 108 provides a differential output capable of up to 500 W
RMS. Power MOSFETS Q1/Q4 and Q5/Q6 (see FIG. 2) are driven by a
first micro U1 to form a first half bridge power amplifier HBPA1,
and power MOSFETS Q9/Q12 and Q13/Q14 are driven by a second micro
U10 to form a second half bridge power amplifier HBPA2. The outputs
of the first half bridge power amplifier HBPA1 and the second half
bridge power amplifier HBPA2 combine at the load (i.e., at the AC
output 102) at 180 degrees out of phase to provide power drive at
the load. Micros U1 and U10 provide fast turn on/off drive to their
respective power MOSFETS to assure efficient switching operation.
Micros U1 and U10 also provide galvanic isolation electrically
isolating the input/output grounds. Micros U3 and U4 cooperate to
provide dead-time control for power MOSFETS Q1/Q4 and Q5/Q6
assuring that they are never on at the same time causing a dead
short for the power supply +PWR_TX. Micros U11 and U12 provide the
same functionality as micros U3 and U4 for Q9/Q12 and Q13/Q14.
Micros U2, U9, U5, and U33 convert the four inputs to the full
bridge amplifier to the necessary drive to derive a differential AC
output voltage at the load (i.e., AC output terminal 102). This
part of the amplifier ensures that the output of each HBPA in the
disable state is ground, essentially keeping power MOSFETS Q5/Q6
for the first half bridge power amplifier HBPA1 and power MOSFETS
Q13/Q14 for the second half bridge power amplifier HBPA2 in the on
state.
[0176] The modulator 110 is configured to selectively provide the
drive signal from the oscillator 106 to the amplifier 108 as a
function of a hysteretic control signal when the bidirectional
power converter 100 is operating in the transmit mode. In one
embodiment, the modulator 110 is an amplitude shift keyed
modulator. The Amplitude Shift Keying Modulator 110 provides a
digitized version of AM (Amplitude Modulation) to the full bridge
amplifier 108, effectively keying on/off the full bridge amplifier
108 dependent on the logic state of the feedback signal (i.e.,
hysteresis control signal) received from a second bidirectional
power converter configured as a receiver (i.e., in the receive
mode). The AMOD 110 effect is to keep the voltage generated at the
DC output terminal of the second bidirectional power converter
assembly output constant. The AMOD 110 accepts four inputs FD_BCK
(i.e., hysteretic control signal), 100 KHz_OSC (i.e., drive signal)
from the oscillator 106, ONE_SHOT (i.e., one shot signal) from the
one shot timer 170, and SSL (i.e., the pulse width modulated
signal) from the slow start logic circuit 172. The AMOD 110
generates four outputs (i.e., two sets of differential outputs) to
the full bridge amplifier 108: 100 KHz_OUT_MODULATED, 100
KHz_OUT_MODULATED N, TX_EN, TX_EN_N. The modulator enable signal
(MODULATOR_EN) enables/disables the AMOD (modulator) 110. Once the
AMOD 110 is enabled, the drive signal from the oscillator 106 (100
KHz_OSC) drives CLK pins of micro U15 and micro U38, sequentially
clocking the logic state of the hysteresis control signal (FD_BCK),
once the one shot signal (ONE_SHOT) has settled to a logic 0 and
the slow start circuit 172 pulse width modulated signal (SSL) has
settled to a logic 1. A modulator internal signal 100
KHz_OUT_MODULATED is derived from micro U38 and its inverted
version from micro U35. The TX_EN and TX_EN_N signals are derived
from the Q/Q N pins of U15B. These outputs drive the full bridge
amplifier 108 and contain the feedback information from the second
bidirectional power converter 100 configured as a receiver. A logic
1 at D of micro U15A turns on the full bridge amplifier 108
continuously while a logic 0 at D of micro U15A turns off the full
bridge amplifier 108 and turns on power MOSFETS Q5, Q6, Q13, and
Q14 to keep each half bridge power amplifier (i.e., HBPA1 and
HBPA2) output at ground potential.
[0177] The hysteretic receiver circuit 112 is configured to receive
a transmitted control signal at the bidirectional power converter
100 and provide the hysteretic control signal to the modulator 110
as a function of the received, transmitted control signal when the
bidirectional power converter 100 is operating in the transmit
mode.
[0178] The transmit relay 114 is configured to electrically connect
the amplifier 108 to the AC terminal 102 of the bidirectional power
converter 100 when the bidirectional power converter 100 is
operating in the transmit mode and electrically disconnect the
amplifier 108 from the AC terminal 102 of the bidirectional power
converter 100 when the bidirectional power converter 100 is
operating in the receive mode.
[0179] The rectifier 116 is configured to receive an alternating
current power signal from the AC terminal 102 of the bidirectional
power converter 100 and provide a DC output to the DC output
terminal 104 of the bidirectional power converter 100 when the
bidirectional power converter 100 is operating in the receive mode.
In one embodiment, the rectifier 116 is a full wave rectifier. The
rectifier 116 converts the AC power received to pulsating DC at
twice the incoming frequency. The rectifier 116 is capable of
receiving up to a maximum of 500 W RMS. The rectifier is
implemented via diodes D14 through D19 and D22 through D27 (see
FIG. 4) connected in a full bridge rectifier configuration. A
parallel diode combination allows for higher power while keeping
the efficiency high. In one embodiment, the diodes D14 through D19
and D22 through D27 are of the Schottky type for high speed
operation.
[0180] The receive relay 118 is configured to enable the rectifier
116 to provide the DC output to the DC output terminal 104 of the
bidirectional power converter 100 when the bidirectional power
converter 100 is operating in the receive mode and prevent the
rectifier 116 from providing the DC output to the DC output
terminal 104 when the bidirectional power converter 100 is
operating the transmit mode. In one embodiment, the receive relay
118 is configured to enable the rectifier 116 to provide the DC
output to the DC output terminal 104 when the bidirectional power
converter 100 is operating in the receive mode by electrically
connecting the rectifier 116 to the DC output terminal 104 of the
bidirectional power converter 100 when the bidirectional power
converter 100 is operating in the receive mode. The receive relay
118 is further configured to prevent the rectifier 116 from
providing the DC output to the DC output terminal 104 when the
bidirectional power converter 100 is operating in the transmit mode
by electrically disconnecting the rectifier 116 from the AC
terminal 102 of the bidirectional power converter 100 when the
bidirectional power converter 100 is operating in the transmit
mode. In another embodiment, the receive relay 118 is configured to
prevent the rectifier 116 from providing the DC output to the DC
output terminal 104 when the bidirectional power converter 100 is
operating in the transmit mode by electrically disconnecting the
rectifier 116 from the DC output terminal 104.
[0181] The hysteretic control circuit 120 is configured to monitor
the DC output and transmit a control signal as a function of the
monitored DC output when the bidirectional power converter 100 is
operating in the receive mode. In one embodiment, the hysteretic
control circuit 120 includes a hysteretic controller 132 and a
transmitter. The hysteretic controller 132 is configured to provide
a logic signal. The logic signal is a 1st binary value when a
voltage of the DC output from the rectifier 116 is less than a
predetermined threshold, and the logic signal is a 2nd binary value
when the voltage of the DC output is more than the predetermined
threshold. The 1st binary value is different than the 2nd binary
value. The response time of the hysteretic controller 132 is almost
instantaneous which gives the system (i.e., a pair of bidirectional
power converters 100, one operating in the transmit mode and one
operating in the receive mode) excellent transient response at the
DC output terminal. The only delays involved in the control loop
are the propagation delays of the transmitter and hysteretic
receiver circuit 112 and other system blocks of the power network
(i.e., modulator 116 and amplifier 108) which are very short.
Another benefit of the hysteretic controller 132 and hysteretic
receiver circuit 112 is that the system has an unconditional
operation stability, requiring no feedback compensating components
for stable operation. In one embodiment, the hysteretic controller
132 further includes a feedback network. The feedback network
provides a reduced voltage representative of the DC output voltage
of the rectifier 116, allowing for the output of the bidirectional
power converter to be adjusted anywhere between 12 and 24 V DC as a
function of the feedback network components (i.e., resistors).
Resistors R92, R95, and R101 (see FIG. 4) and capacitor C89 provide
the feedback network function. Resistors R92, R95, and R101 form a
voltage divider that divides down the output voltage (i.e., the DC
output voltage from the rectifier 116 and DC filter 186) to equal a
reference voltage applied to the hysteretic controller 132 by the
linear regulator 182. At any time the output is regulated between
12-24V, the voltage generated across R101 is always 2.5V which is
equal to the reference voltage of micro U23A provided by the linear
regulator 182. Capacitor C89 is used to pass some of the ripple of
the DC output signal from the rectifier 116 and DC filter 186 to
the input of the micro U23A to speed up the switching action of the
hysteretic controller 132, increasing efficiency and stability of
the bidirectional power converter. In a 1st embodiment of the
hysteretic controller 132, the transmitter is a coil pulse driver
140 configured to receive the logic signal and generate a magnetic
field via a magnetic coupling coil. The generated magnetic field is
indicative of the logic signal. In the 1st embodiment, the
hysteretic receiver circuit 112 includes a magnetic sensor
configured to receive a magnetic field and provide hysteretic
control signal to the modulator 110 as a function of the received
magnetic field. In one version, a linear hall-effect sensor
connects to jumper J3 of the bidirectional power converter 100.
Micro U6A is configured as an AC coupled first-order low pass
filter, for removing some noise picked up by the hall-effect
sensor. Micro U6B and comparator U41A form a comparator circuit
with a threshold set by micro U6B. When the output of micro U6A
equals the threshold set by micro U6B, comparator U41A sets its
output (i.e., the hysteresis control signal) to a logic 1, and the
comparator U41A sets its output (i.e., the hysteresis control
signal) to a logic zero when the output of micro U6A is less than
the threshold set by micro U6B. In a 2nd embodiment, the
transmitter is a radio frequency (RF) transmitter configured to
receive the logic signal and transmit an RF signal via and antenna,
wherein the transmitted RF signal is indicative of the logic
signal. In the 2nd embodiment, hysteretic receiver circuit 112
includes an RF receiver configured to receive an RF signal and
provide the hysteretic control signal to the modulator 110 as a
function of the received RF signal. In a 3rd embodiment, the
transmitter is an optical transmitter 142 configured to receive the
logic signal and transmit an optical signal via an infrared
emitter, wherein the transmitted optical signal is indicative of
the logic signal. In the 3rd embodiment, the hysteretic receiver
circuit 112 includes an infrared receiver 144 configured to receive
an optical signal and provide the hysteretic control signal to the
modulator 110 as a function of the received optical signal.
[0182] In one embodiment, the bidirectional power converter 100
further includes a direction control input 130 configured to
receive a direction control signal. The direction control signal is
provided to the transmit relay 114 and the receive relay 118 to set
the bidirectional power converter 100 in either the transmit mode
or the receive mode.
[0183] In one embodiment, the bidirectional power converter 100
further includes a coil 150 connected to the AC terminal 102 of the
bidirectional power converter 100. The coil 150 is configured to
receive the AC output signal from the amplifier 108 and emit a
corresponding electromagnetic field when the bidirectional power
converter 100 is operating in the transmit mode. The coil 150 is
further operable to convert electromagnetic flux into an AC power
signal when the bidirectional power converter 100 is operating in
the receive mode. In one embodiment, the coil 150 includes a wire
coil 152 and a tuning capacitor 154. The tuning capacitor 154
connects the wire coil 152 to the AC terminal 102 of the
bidirectional power converter 100.
[0184] In one embodiment, the bidirectional power converter 100
further includes a DC charge control relay 160 (which can be
external to other components) including a unified DC terminal 162.
The DC control relay 160 is configured to connect to the DC input
terminal 122 and the DC output terminal 104. The DC charge control
relay 160 is configured to electrically isolate the DC input
terminal 122 from the DC output terminal 104. The DC charge control
relay 160 further electrically connects the DC input terminal 122
to the unified DC terminal 162 when the bidirectional power
converter 100 is operating in the transmit mode and electrically
connects the DC output terminal 104 to the unified DC terminal 162
when the bidirectional power converter 100 is operating in the
receive mode.
[0185] In one embodiment, bidirectional converter 100 further
includes a slow start circuit 172 and a one-shot timer 170. The
slow start circuit 172 is configured to provide a pulse width
modulated signal that increases from 0 to 100% duty cycle (i.e.,
"on" time) beginning when the bidirectional power converter 100
begins operating in the transmit mode. The rate of increase of the
duty cycle of the pulse width modulated signal is generally linear.
The effect of the pulse width modulated signal (SSL) from the slow
start circuit 172 is to control the amount of time the amplifier
108 remains in the on-state. This function is only used initially
when the bidirectional power converter 100 is enabled to transmit
for the first time (i.e., at each startup of the bidirectional
power converter 100 as a transmitter). The pulse width modulated
signal (SSL) varies the on-time of the amplifier 108 from 0 (fully
off) to 1 (fully on continuously) by controlling the on-time at the
modulator 110, effectively ramping up the voltage received at a
second bidirectional power converter 100 configured as a receiver
until a set regulated voltage (i.e., a target output voltage) is
reached. Once the set voltage is reached, the output of the SSL
remains at a logic 1. In one embodiment, of the slow start circuit
172, micro U16B is configured as a saw-tooth oscillator. The output
of micro U16B, taken across capacitors C41 and C42, is fed to PWM
comparator U16A. A linear DC voltage is generated across a
capacitor bank (i.e., capacitors C35, C36, C37, C38, and C39) by
feeding the capacitor bank a constant current generated by switch
Q18. This linear generated DC voltage is compared in PWM comparator
U16A to the saw-tooth like ramp voltage generated by micro U16B and
a pulse width modulated signal is generated by PWM comparator U16A
to provide to the modulator 110.
[0186] The one-shot timer 170 is configured to provide a one-shot
signal to the modulator 110 (and the one shot signal is "on") when
the bidirectional power converter 100 begins operating in the
transmit mode and for a predetermined period of time thereafter.
Modulator 110 is further configured to provide the drive signal
from the oscillator 106 to amplifier 108 when the pulse width
modulated signal is on and at least one of the hysteretic control
signal and one-shot signal are "on." In one embodiment, the one
shot timer 170 provides a precise time controlled "momentary-on"
enable signal to the AMOD (i.e., modulator 110) when the
transmitter section is first enabled. If, in the time frame
generated by the one shot timer 170, a feedback signal (i.e.,
hysteresis control signal) is not received by the bidirectional
power converter 100, the one shot timer 170 terminates the
transmission. That is, the modulator 110 ceases providing the drive
signal from the oscillator 106 to the amplifier 108 because the
modulator 110 is receiving neither the hysteresis control signal
nor the one shot signal. In addition, this embodiment permits the
transmit section to terminate operation in the event the feedback
signal is interrupted, once it has been received. Micro U42 (see
FIG. 3) is the one shot timer 170 designed utilizing a standard 555
timer. The on-time of the one shot signal is controlled by resistor
R146 and capacitors C133 and C134. The modulator enable signal
(MODULATOR_EN) provided by the control logic 176 triggers the one
shot timer 170 via pin 2 of micro U42 (i.e., 555 timer) through
switch Q37.
[0187] In one embodiment, the bidirectional power converter 100
further includes a temperature sensor 174 and control logic 176.
The temperature sensor 174 is configured to monitor a temperature
of the amplifier 108 and provide a temperature sensing signal
indicative of the monitored temperature. The control logic 176 is
configured to provide a modulator enable signal to the modulator
110 as a function of the temperature sensing signal and the
direction signal such that the modulator enable signal is provided
when the direction control signal sets the bidirectional power
converter 100 in the transmit mode and the temperature sensing
signal is indicative of a temperature less than a predetermined
temperature. The modulator 110 does not provide the drive signal
from the oscillator 106 to the amplifier 108 when the modulator 110
is not receiving a modulator enable signal. In one embodiment, the
temperature sensor 174 monitors the full bridge amplifier 108 via
thermal coupling of the temperature sensor 174 to the full bridge
amplifier 108. When the temperature at the full bridge amplifier
108 reaches a threshold set by the temperature sensor 174, the
temperature sensor 174 sets its output disabling the full bridge
amplifier 108 via the modulator 110. When the temperature at the
full bridge amplifier 108 drops to a safe value, the temperature
sensor 174 re-enables the full bridge amplifier 108 via the
modulator 110. The status of the temperature sensor 174 can be
obtained from the signal connector at pin-6. In one embodiment,
micro U14 is an integrated circuit manufactured by Maxim
Integrated.TM. capable of +/-0.5 degree C. accuracy and a
temperature range of -20 to 100 degree C. Resistors R51, R53, and
R53 and switch Q17 set the two set points for micro U14. In one
embodiment, the set points disable at 80 C and enable at 40 C. In
one embodiment of the control logic 176, the control logic 176
takes in the signals from the temperature sensor 174 (TEMP_EN_DIS)
and the TX_ON signal from signal connector pin-2 and generates a
single enable/disable signal (MODULATOR_EN) for the modulator 110.
Micros U39 and U40 provide the logic function needed for the
control logic 176. When the output from the temperature sensor 174
(TEMP_EN_DIS) is logic 0 and transmitter enable signal from pin 2
of the signal connector (TRANS_EN) is logic 1, modulator enable
signal (MODULATOR_EN) is a logic 1, enabling the transmit function
of the bidirectional power converter 100.
[0188] In one embodiment, the bidirectional power converter 100
further includes a switching regulator 180. The switching regulator
180 is configured to generate bias voltages when the bidirectional
power converter 100 is receiving power from the power source at the
DC input terminal 122 of the bidirectional power converter 100.
Switching regulator 180 provides at least one of the generated bias
voltages to the oscillator 106, the amplifier 108, the modulator
110, the hysteretic receiver circuit 112, and the transmit relay
114, the slow start circuit 172, the one-shot timer 170, and the
temperature sensor 174. In one embodiment, the switching regulator
180 implements a buck switching type regulator.
[0189] In one embodiment, the bidirectional power converter 100
further includes a linear regulator 182. The linear regulator 182
is configured to receive the DC output from the rectifier 116 and
provide bias voltages to the hysteretic control circuit 120 when
the bidirectional power converter 100 is operating in the receive
mode.
[0190] In one embodiment, the bidirectional power converter 100
further includes a DC filter 186 configured to relay the DC output
provided by the rectifier 116 to the DC output terminal 104. The DC
filter 186 converts the pulsating DC output from the rectifier 116
to a fixed DC voltage with relatively low ripple. Capacitor bank
C76 through C80 charge to the peak value of the rectified AC
voltage (i.e., the pulsating DC output provided by the rectifier
116) and supply power to the load (i.e., the DC output terminal)
during certain times (i.e., the troughs) of the pulsating DC output
signal provided by the rectifier 116.
[0191] In one embodiment, the bidirectional power converter 100
further includes a plurality of isolators 190. The plurality of
isolators 190 are configured to isolate the DC input terminal 122
from the AC terminal 102 and the AC terminal 102 from the DC output
terminal 104 of the bidirectional power converter 100 such that the
bidirectional power converter 100 is an isolated power source in
both the transmit mode and the receive mode.
[0192] Referring now to FIGS. 6-13, a proximity wireless power
transfer system 600 includes a proximity wireless power transmitter
602 and a proximity wireless power receiver 604. The proximity
wireless power transmitter 602 is configured to periodically test
for the presence of the proximity wireless power receiver 604 and
provide power to proximity wireless power receiver 604 when it is
within range of the proximity wireless power transmitter 602. The
proximity wireless power transmitter includes a bidirectional power
converter 606, a DC power source 608, a tuning capacitor 610, a
wire coil 612, and automatic turn on assembly 614, a voltage detect
circuit 616, and a RF receiver 618. The proximity wireless power
receiver 604 includes a bidirectional power converter 630 and an RF
transmitter 632. In one embodiment, the bidirectional power
converter 630 is the same as the bidirectional power converter 100,
and the bidirectional power converter 606 is the same as the
bidirectional power converter 100 as described above.
[0193] The bidirectional power converter 606 is operable to provide
AC power and an AC terminal 620 of the bidirectional power
converter 606 when in a transmit mode of the bidirectional power
converter 606 and enabled via a transmitter enable signal or a
hysteresis control signal.
[0194] The DC power source 608 is configured to provide power to DC
input terminal 622 of the bidirectional power converter 606 and a
directional control signal to a direction control input 640 of the
bidirectional power converter 606. The direction control signal
indicates a transmit mode of the bidirectional power converter 606.
The wire coil 612 is connected in series with the tuning capacitor
610 to the AC terminal 620 of the bidirectional power converter
606. The wire coil 612 is configured to receive an AC output signal
from an amplifier of the bidirectional power converter 606 and emit
a corresponding electromagnetic field.
[0195] The automatic turn on assembly 614 is configured to provide
the transmitter enable signal to the bidirectional power converter
606. The automatic turn on assembly 614, when enabled, is
configured to selectively enable and disable the bidirectional
power converter 606 via the transmitter enable signal.
[0196] The voltage detect circuit 616 is configured to determine a
voltage across the tuning capacitor 610 and reset the automatic
turn on assembly 614 whenever the voltage across the tuning
capacitor 610 exceeds a predetermined threshold. The automatic turn
on assembly 614 disables the bidirectional power converter for a
predetermined period of time via the transmitter enable signal when
the automatic turn on assembly 614 is reset.
[0197] The RF receiver 618 is configured to receive the
radiofrequency signal from an RF transmitter 632 of the cart
bidirectional power converter receiver 634 receiving power from the
proximity wireless power transmitter and provide the hysteresis
control signal to the bidirectional power converter as a function
of the received radiofrequency signal.
[0198] The cart bidirectional power converter receiver 604 is
configured to provide the RF signal as a function of a DC voltage
of the DC output terminal 650 of the cart bidirectional power
converter 630. In one embodiment, the RF signal carries a binary 0
when the DC voltage at the DC output terminal 650 of the cart
bidirectional power converter 630 is above a predetermined
threshold (e.g., 12 V) and a binary one when the DC voltage at the
DC output terminal 650 is less than the predetermined threshold. In
another embodiment, the RF signal carries a binary 0 when the DC
voltage at the DC output terminal 650 of the cart bidirectional
power converter 630 is above a first predetermined threshold (e.g.,
24.5 V) and a binary one when the DC voltage of the DC output
terminal 650 is less than a second predetermined threshold (e.g.
23.5 V).
[0199] It will be understood by those of skill in the art that
information and signals may be represented using any of a variety
of different technologies and techniques (e.g., data, instructions,
commands, information, signals, bits, symbols, and chips may be
represented by voltages, currents, electromagnetic waves, magnetic
fields or particles, optical fields or particles, or any
combination thereof). Likewise, the various illustrative logical
blocks, modules, circuits, and algorithm steps described herein may
be implemented as electronic hardware, computer software, or
combinations of both, depending on the application and
functionality. Moreover, the various logical blocks, modules, and
circuits described herein may be implemented or performed with a
general purpose processor (e.g., microprocessor, conventional
processor, controller, microcontroller, state machine or
combination of computing devices), a digital signal processor
("DSP"), an application specific integrated circuit ("ASIC"), a
field programmable gate array ("FPGA") or other programmable logic
device, discrete gate or transistor logic, discrete hardware
components, or any combination thereof designed to perform the
functions described herein. Similarly, steps of a method or process
described herein may be embodied directly in hardware, in a
software module executed by a processor, or in a combination of the
two. A software module may reside in RAM memory, flash memory, ROM
memory, EPROM memory, EEPROM memory, registers, hard disk, a
removable disk, a CD-ROM, or any other form of storage medium known
in the art. Although embodiments of the present invention have been
described in detail, it will be understood by those skilled in the
art that various modifications can be made therein without
departing from the spirit and scope of the invention as set forth
in the appended claims.
[0200] A controller, processor, computing device, client computing
device or computer, such as described herein, includes at least one
or more processors or processing units and a system memory. The
controller may also include at least some form of computer readable
media. By way of example and not limitation, computer readable
media may include computer storage media and communication media.
Computer readable storage media may include volatile and
nonvolatile, removable and non-removable media implemented in any
method or technology that enables storage of information, such as
computer readable instructions, data structures, program modules,
or other data. Communication media may embody computer readable
instructions, data structures, program modules, or other data in a
modulated data signal such as a carrier wave or other transport
mechanism and include any information delivery media. Those skilled
in the art should be familiar with the modulated data signal, which
has one or more of its characteristics set or changed in such a
manner as to encode information in the signal. Combinations of any
of the above are also included within the scope of computer
readable media. As used herein, server is not intended to refer to
a single computer or computing device. In implementation, a server
will generally include an edge server, a plurality of data servers,
a storage database (e.g., a large scale RAID array), and various
networking components. It is contemplated that these devices or
functions may also be implemented in virtual machines and spread
across multiple physical computing devices.
[0201] This written description uses examples to disclose the
invention and also to enable any person skilled in the art to
practice the invention, including making and using any devices or
systems and performing any incorporated methods. The patentable
scope of the invention is defined by the claims, and may include
other examples that occur to those skilled in the art. Such other
examples are intended to be within the scope of the claims if they
have structural elements that do not differ from the literal
language of the claims, or if they include equivalent structural
elements with insubstantial differences from the literal languages
of the claims.
[0202] It will be understood that the particular embodiments
described herein are shown by way of illustration and not as
limitations of the invention. The principal features of this
invention may be employed in various embodiments without departing
from the scope of the invention. Those of ordinary skill in the art
will recognize numerous equivalents to the specific procedures
described herein. Such equivalents are considered to be within the
scope of this invention and are covered by the claims.
[0203] All of the compositions and/or methods disclosed and claimed
herein may be made and/or executed without undue experimentation in
light of the present disclosure. While the compositions and methods
of this invention have been described in terms of the embodiments
included herein, it will be apparent to those of ordinary skill in
the art that variations may be applied to the compositions and/or
methods and in the steps or in the sequence of steps of the method
described herein without departing from the concept, spirit, and
scope of the invention. All such similar substitutes and
modifications apparent to those skilled in the art are deemed to be
within the spirit, scope, and concept of the invention as defined
by the appended claims.
[0204] Thus, although there have been described particular
embodiments of the present invention of a new and useful PROXIMITY
WIRELESS POWER SYSTEMS USING A BIDIRECTIONAL POWER CONVERTER it is
not intended that such references be construed as limitations upon
the scope of this invention except as set forth in the following
claims.
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