DE102020108800A1 - WIRELESS POWER SYSTEM WITH RECONFIGURABLE RECTIFIER CIRCUIT - Google Patents

Abstract

A wireless charging system includes a wireless power transmission device and a wireless power receiving device. The wireless power transfer device may be a wireless charging mat or other device having coils for transferring wireless power signals. The wireless power receiving device may be a cellular phone or other device having coils for receiving the transmitted wireless power signals. The wireless power receiving device has adjustable rectifier circuits coupled to a pair of coils. The coil pair is connected in series at a node. A transistor is coupled between ground and the node and is controlled by a control circuit. The state of the transistor can be changed in order to put the adjustable rectifier circuit either in a first operating mode in which the adjustable rectifier circuit forms a full bridge rectifier, or in a second operating mode in which the adjustable rectifier circuit forms a pair of parallel half bridge rectifiers.

Description

This patent application claims the priority of U.S. Patent Application No. 16 / 505,370 , filed July 8, 2019, and the preliminary U.S. Patent Application No. 62 / 828,933 , filed April 3, 2019, which are hereby incorporated by reference in their entirety.

TECHNICAL AREA

This relates to power systems in general and, more particularly, to wireless power systems for charging electronic devices.

BACKGROUND

In a wireless charging system, a wireless transmitting device such as a charging mat wirelessly transmits power to a wireless charging receiving device such as a portable electronic device. The portable electronic device has a coil and rectifier circuit. The coil of the handheld electronic device receives wireless AC power signals from the wireless charging mat. The rectifier circuit converts the received signals into direct current.

ABSTRACT

A wireless charging system includes a wireless power transmission device and a wireless power receiving device. The wireless power transfer device is a wireless charging mat or other device with coils for transferring wireless power signals. The wireless power receiving device is a cellular phone or other device having coils for receiving the transmitted wireless power signals.

To improve the efficiency of wireless power transmission in a variety of operating scenarios, the wireless power receiving device can configure the coils in the wireless power receiving device to receive magnetic flux emitted by the wireless power transmitting device in a first orientation (e.g., horizontal flux). or a second orientation (e.g. vertical flow).

The wireless power receiving device has adjustable rectifier circuits coupled to a pair of coils. When wireless power is received, a first of the coils may generate AC signals that are in phase or out of phase (e.g., 180 degrees out of phase) with respect to a second of the coils, depending on the orientation of the magnetic flux being transmitted. The adjustable rectifier circuit is dynamically reconfigured to accommodate these different scenarios.

The first and second coils are coupled in series at a node. A transistor is coupled between ground and the node. The transistor is controlled by a control circuit. The state of the transistor can be changed in order to put the adjustable rectifier circuit either in a first operating mode in which the adjustable rectifier circuit forms a full bridge rectifier, or in a second operating mode in which the adjustable rectifier circuit forms a pair of parallel half bridge rectifiers.

Figure list

• 1 FIG. 13 is a schematic diagram of an illustrative wireless charging system including a wireless power transmitting device and a wireless power receiving device, according to an embodiment.
• 2 Figure 13 is a circuit diagram of the wireless power transmission and reception circuit according to an embodiment.
• 3 Figure 13 is a side view of an illustrative wireless power transmission device, such as a wireless charging mat, and a corresponding wireless power receiving device, such as a cellular phone having a plurality of wireless power receiving coils, according to one embodiment.
• 4th Figure 4 is a circuit diagram of an illustrative adjustable rectifier circuit in accordance with one embodiment.

DETAILED DESCRIPTION

A wireless power system includes a wireless power transfer device such as a wireless charging mat. The wireless power transmission device wirelessly transmits power to a wireless power receiving device such as a wrist watch, cell phone, tablet computer, laptop computer, or other electronic device. The wireless power receiving device uses power from the wireless power transmitting device to provide power to the device and to charge an internal battery.

The wireless power transmission device communicates with the wireless power receiving device and receives information about the Characteristics of the wireless power receiving device. In some embodiments, the wireless power transmission device includes multiple transmission coils. In such embodiments, the wireless power transmitting device uses information from the wireless power receiving device, or measurements taken in the wireless power transmitting device, to determine which coil or coils in the transmitting device are magnetically coupled to wireless power receiving devices. The coil selection is then performed in the wireless power transmission device.

Wireless power is transmitted from the wireless power transmission device to the wireless power receiving device using the selected coil (s) to charge a battery in the wireless power receiving device or to power other load circuits. The wireless power receiving device has reconfigurable coils. For example, the wireless power receiving device may include a pair of coils coupled to an adjustable rectifier circuit. The rectifier circuit can be operated in different modes of operation to improve the wireless power reception by the coils.

An illustrative wireless power system (wireless charging system) is shown in FIG 1 shown. As in 1 shown closes the wireless power system 8th a wireless power transmission device such as a wireless power transmission device 12 , and includes a wireless power receiving device such as a wireless power receiving device 24 , one. The wireless power transmission device 12 closes a control circuit 16 one. The wireless power receiving device 24 closes a control circuit 30th one. The control circuit in the system 8th how the control circuit 16 and the control circuit 30th , is used in controlling the operation of the system 8th used. This control circuit can include processing circuitry associated with microprocessors, power management units, baseband processors, digital signal processors, microcontrollers, or application-specific integrated circuits with processing circuits. The processing circuit implements desired control and communication features in the devices 12 and 24 . For example, the processing circuitry can assist in selecting the coils, determining the current transmission levels, processing the sensor data and other data, processing the user input, handling the negotiations between the devices 12 and 24 , to send and receive in-band and out-of-band data, to take measurements, and to otherwise control the operation of the system 8th be used.

A control circuit in the system 8th can be configured to handle operations in the system 8th using hardware (e.g., dedicated hardware or circuitry), firmware and / or software. Software code for performing operations on the system 8th is stored on non-transitory, computer-readable storage media (e.g. tangible, computer-readable storage media) in the control circuit 8th saved. The software code can sometimes be referred to as software, data, program instructions, instructions, or code. The non-volatile, computer-readable storage media may include non-volatile memory such as non-volatile memory (NVRAM), one or more hard drives (e.g., magnetic drives or solid-state drives), one or more removable flash drives or other removable media, or the like . Software stored on the non-transitory, computer-readable storage media can be used on the processing circuit of the control circuit 16 and or 30th are executed. The processing circuitry may include application specific integrated circuits with processing circuitry, one or more microprocessors, a central processing unit (CPU), or other processing circuitry.

The device 12 can be a standalone power adapter (e.g., a wireless charging mat or a charging disk that includes a power adapter circuit), can be a wireless charging mat or a charging disk that is wired to a power adapter or other equipment, can be a portable device can be equipment built into furniture, a vehicle, or other system, can be a detachable battery case, or can be other wireless power transmission equipment. Illustrative configurations in which the wireless power transmission device 12 is a wireless charging mat are sometimes described herein as an example.

The power receiving device 24 can be a portable electronic device such as a wrist watch, cell phone, laptop computer, tablet computer, or other electronic equipment. The power transmission device 12 may be mated to an electrical outlet (e.g., an AC power source), may have a battery pack to provide power, or may have another source of power. The power transmission device 12 can use an AC-DC power converter, such as an AC-DC power converter 14th , for converting AC power from an outlet or another Have power source in DC power. DC power can be used to power the control circuit 16 to provide electricity. During operation, a controller is used in the control circuit 16 a power transmission circuit 52 to wirelessly deliver power to a power receiving circuit 54 the device 24 transferred to. The power transmission circuit 52 can be a switching circuit (e.g. an inverter made up of transistors 61 ), based on control signals from the control circuit 16 is switched on and off to alternate current signals through one or more coils 36 to create. The spools 36 may be arranged in a planar coil arrangement (e.g., in configurations in which the device 12 is a wireless charging mat) or can be arranged to form a cluster of coils (e.g. in configurations in which the device 12 is a wireless charging disc). In some arrangements the device has 12 only one coil on. In other arrangements, a wireless charging device, such as a wireless charging mat, may have multiple coils (e.g., two or more coils, 5-10 Coils, at least 10 Do the washing up, 10-30 Coils, less than 35 Coils, less than 25th Coils or some other suitable number of coils).

When the alternating currents through one or more coils 36 Passing through it, AC electromagnetic fields (e.g., magnetic fields) (wireless power signals 44 ) generated by one or more corresponding coils, such as the coil (s) 48 in the power receiving device 24 received. The device 24 can be a single coil 48 , at least two coils 48 , at least three coils 48 , at least four coils 48 or any other suitable number of coils 48 exhibit. In an illustrative configuration, which can sometimes be described herein as an example, the apparatus has 24 a pair of coils 48 on. When the alternating current electromagnetic fields through the coils 48 are received, corresponding alternating currents in the coils 48 induced. A rectifier circuit like the rectifier circuit 50 containing rectifier components such as synchronous rectifier metal-oxide semiconductor transistors arranged in a bridge network, converts received AC signals (received AC signals, the electromagnetic signals 44 assigned) of one or more coil (s) 48 into DC voltage signals for supplying the device 24 around.

The ones from the rectifier circuit 50 Generated DC voltages (sometimes referred to as rectifier output voltage Vcr 58 and can be used to supply other components in the device 24 be used with electricity. For example, the device 24 Input-output devices 56 such as a display, a touch sensor, communication circuits, audio components, sensors, light emitting diode status indicators, other light emitting and light sensing components, and other components, and these components (which place a load on the device 24 form) can be matched by the rectifier circuit 50 generated DC voltages (or from the battery 58 generated DC voltages).

The device 12 and / or the device 24 can communicate wirelessly using in-band or out-of-band communications. The device 12 for example, a wireless transceiver circuit 40 that wirelessly send out-of-band signals to the device using an antenna 24 transmits. The wireless transceiver circuit 40 can be used to wirelessly receive out-of-band signals from the device 24 using the antenna to receive. The device 24 can be a wireless transceiver circuit 46 have the out-of-band signals to the device 12 transmits. A receiver circuit in the wireless transceiver 46 can use an antenna to receive out-of-band signals from the device 12 to recieve. In-band transmissions between devices 12 and 24 can using the coils 36 and 48 be performed. In an illustrative configuration, frequency shift keying (FSK) is used to receive in-band data from the device 12 to the device 24 and amplitude shift keying (ASK) is used to transfer in-band data from the device 24 to the device 12 transferred to. Power can wirelessly from the device during these FSK and ASK transmissions 12 to the device 24 be transmitted.

It is desirable that the transmission device 12 and the receiving device 24 are able to communicate information such as received power, state of charge, and so on to control wireless power transmission. However, the technology described above need not involve the transmission of personally identifiable information in order to function. To exercise the utmost caution, it should be noted that any implementation of this charging technology involves the use of personally identifiable information, which implementers should adhere to data protection regulations and practices that are generally recognized to meet industry or government requirements for maintaining the privacy of Meet or exceed users. In particular, personally identifiable information data should be managed and handled in such a way that risks of a unintentional or unauthorized access or use should be minimized, and the nature of authorized use should be clearly indicated to users.

The control circuit 16 instructs the external object measurement circuit 41 , on that can be used to place external objects on the back of the device 12 (e.g. to detect on the top of a charging mat, or, if desired, to detect objects in the vicinity of the coupling surface of a charging disc). The circuit 41 can detect foreign objects such as coils, paper clips, and other metallic objects; and can detect the presence of wireless power receiving devices 24 capture (e.g. the circuit 41 the presence of one or more coils 48 to capture). During object detection and characterization operations, the external object measurement circuitry can 41 used to take measurements on coils 36 perform to determine if any devices 24 in the device 12 available.

In an illustrative arrangement, the measurement circuit includes 41 the control circuit 16 a signal generation circuit (e.g., an oscillator circuit for generating AC probe signals at one or more probe frequencies, a pulse generator capable of generating pulses so that impulse responses can be measured to collect inductance information, Q-factor information, etc.) and a signal detection circuit (e.g. B. Filters, analog-to-digital converters, impulse response measurement circuits, etc.). During the measurement processes, the switching circuit in the device 12 by the control circuit 16 be adjusted so that each of the coils 36 is switched to operation. As every coil 36 is selectively switched into operation, uses the control circuit 16 the signal generating circuit of the signal measuring circuit 41 to apply a probe signal to this coil while passing the signal detection circuit of the signal measurement circuit 41 used to measure an appropriate response. A measuring circuit 43 in the control circuit 30th or in the control circuit 16 can also be used when making current and voltage measurements. Based on this information or other information, the control circuit 30th the rectifier circuit 50 configure to improve wireless reception through the coils 48 to contribute. For example, the rectifier circuit 50 be configured to operate in a vertical field mode in scenarios where magnetic fields are transmitted from the device 12 are predominantly vertical (e.g. when the coils 36 by the coils 48 overlapped, operated in phase), and can be configured to operate in a horizontal field mode in scenarios where magnetic fields transmitted from the device 12 are predominantly horizontal (e.g. when the coils 36 by the coils 48 overlapped, operated out of phase).

2 Figure 4 is a circuit diagram of an illustrative wireless power circuit for the system 8th . As in 2 shown, the circuit arrangement 52 Inverter circuits such as one or more inverters 61 or other driver circuits that generate wireless power signals that are transmitted by an output circuit comprising one or more coils 36 and capacitors like the capacitor 70 includes. In some embodiments the device comprises 12 several individually controlled inverters 61 , each of which sends the drive signals to a respective coil 36 supplies. In other embodiments, an inverter 61 between multiple coils 36 shared using switching circuits.

Control signals for the inverter (s) are sent during operation 61 from the control circuit 16 at the control input 74 provided. A single inverter 61 and a single coil 36 are in the example of 2 shown, but multiple inverters 61 and multiple coils 36 can be used if desired. In a multi-coil configuration, switching circuitry can be used to drive a single inverter 61 with multiple coils 36 to couple, or each coil 36 can with a respective inverter 61 be coupled. During wireless power transmission operations, transistors are used in one or more selected inverters 61 by AC control signals from the control circuit 16 driven. This causes the out of the selected coil 36 and the capacitor 70 Output circuit formed electromagnetic alternating current fields (signals 44 ) generated by the wireless receiving circuit 54 using one of one or more coils 48 and one or more capacitors 72 in the device 24 formed wireless receiving circuit are received. If desired, the relative phase between the driven coils can be adjusted 36 (e.g. the phase of one of the coils 36 relative to another driven adjacent coil 36 is driven) can be adjusted by a control circuit 16 circuit 16 in order to improve the wireless transmission between devices 12 and device 24 to improve. The rectifier circuit 50 is with one or more coils 48 (e.g. a pair of coils) and provides a corresponding direct current output voltage V Gleichger. via rectifier output connections 76 ready to have a charging circuit in the device 24 (e.g. for charging the battery 58 , to the Supplying a display or another input-output device 56 with electricity or to supply other components) with electricity. A single coil 48 or multiple coils 48 can in the device 24 be included. In an illustrative configuration, the device 24 a cell phone or other portable device with a pair of coils 48 be. Other configurations can be used if desired.

3 Figure 3 is a cross-sectional side view of the system 8th in an illustrative configuration in which the wireless power transmission device 12 is a wireless charging mat and in which the wireless power receiving device 24 is a mobile phone (as an example). The device 12 has a housing 90 (e.g., a mat housing formed from a polymer, other dielectric material, or other materials). The cable 92 can with the housing 90 be coupled and the device 12 Provide performance. In some configurations, power can be provided by an internal battery.

The device 24 can be a housing, such as a housing 96 , exhibit. The case 96 and the device 24 can have opposite front and rear faces like the front F. and the back R. exhibit. The ad 99 can on the front F. of the housing 96 and the device 24 be formed and lie in a plane that is perpendicular to the Z-axis (e.g. a plane like the XY plane 3 that are parallel to the planes with the front side F. and the back R. of the housing 96 is) stands.

The coils in the devices 12 or. 24 have any suitable number of turns of wire. In some configurations, the coils can be formed from turns of wire formed around cores of iron, ferrite, or other magnetic material.

During the wireless power transmission, the device can 12 one or more coils 36 use to transmit wireless power signals. For example, the coils 48 the device 24 a pair of coils in the device 12 how the coils 36 ''' and 36 '''' overlap. The spools 36 ''' and 36 '''' can be connected to the respective inverter 61 be coupled. During operation, the control circuits 16 these respective inverters instruct the appropriate coils 36 ''' and 36 '''' to be driven in phase (e.g. by corresponding in-phase magnetic fields B1 and B2 to create). That from the device 12 The magnetic field generated in this type of arrangement can be predominantly vertical through the coils 48 extend parallel to the vertical Z-axis of 3 stand. Accordingly, the operation of the device 12 in a configuration in which the coils 36 ''' and 36 '''' operated in phase, sometimes as operating the device 12 can be designated in a vertical field mode. In other arrangements, the control circuit 16 the inverter 61 that with the coils 36 ''' and 36 '''' are coupled to use the coils 36 ''' and 36 '''' to operate out of phase. The inverter circuit of the device 12 can, as an example, the coils 36 ''' and 36 '''' drive 180 ° out of phase (e.g., by corresponding phase-shifted magnetic fields B1 and B2 ' to create). This creates horizontal magnetic fields (e.g. magnetic field lines that are parallel to the XY plane of the 3 and parallel to the loading surface of the device 12 extend). Operation of the device 12 this configuration can sometimes be referred to as a horizontal field mode. Some wireless power receiving devices, such as the illustrative wireless power receiving device 24 ' , can (a) coil (s) 48 that is / are oriented to receive / receive horizontal magnetic fields (e.g. horizontal field bra that by driving the coils 36 ' and 36 ″ are generated 180 ° out of phase with each other).

As these examples show, the coils affect 36 intended for use in the device 12 are selected and the relative phase of the drive currents supplied to the selected coils 36 applied during operation, the position and orientation of the coils 36 generated magnetic fields. The position and orientation of the magnetic fields generated by the coils 36 and the position and orientation of the coils 48 relative to these fields can affect the efficiency of wireless power transmission. In an illustrative arrangement, sometimes described herein as an example, the apparatus comprises 24 a pair of coils 48 on that with an adjustable rectifier circuit 50 is coupled. In this arrangement, the rectifier circuit 50 received wireless power from a pair of coils (first and second coils 48 ) convert into direct current power.

The receiving circuit 50 becomes dynamic by the control circuit 16 set to improve wireless performance reception. As an example, the control circuit 16 the rectifier circuit 50 Configure to operate in a vertical field mode suitable for enhancing wireless power reception of vertical magnetic fields or a horizontal field mode suitable for enhancing wireless power reception of horizontal magnetic fields. In the vertical field mode, the magnetic fields are B1 and B2 that from the first and second coils 48 are received, generally in phase and the rectifier circuit 50 is designed to convert these in-phase wireless power signals to DC power. In the horizontal field mode, the magnetic fields are B1 and B2 ' received by the first and second coils are generally out of phase with each other (e.g., 180 degrees out of phase) and the rectifier circuit 50 is reconfigured to convert these wireless power signals to DC power.

4th Figure 4 is a circuit diagram of an illustrative adjustable circuit used in forming an adjustable rectifier 50 for the wireless power receiving device 24 can be used. As in 4th shown can wireless power on a pair of coils 48 in the device 24 like the first coil C1 and the second C2 be received. The spools C1 and C2 can for example in the housing 96 the device 24 be appropriate, as in 3 shown. The spools C1 and C2 may have turns of wire wound in the same direction (e.g., both clockwise or both counterclockwise), or may, as in 4th shown have opposite winding directions (e.g. coil C1 be wound clockwise (CW) while coil C2 counterclockwise (CCW)). The capacitors 72 can between the coils 48 and the knot N3 and N5 be arranged as inputs (input connections) for adjustable rectifier circuits 50 serve. During the operation of the rectifier circuit 50 becomes the DC output voltage V via the output terminals 76 to supply the load 100 (e.g. to supply the input / output devices 56 to charge the battery 58 and for supplying power to other circuitry in the power receiving device 24 ) generated. The condenser 102 can through the connections 76 parallel to the load 100 coupled to help reduce voltage ripple.

The spools C1 and C2 can be in series between nodes N2 and N4 be coupled. The sink C1 may have a first connector that connects to the node N2 is coupled, and a second connector that connects to the node N1 is coupled. The sink C2 may have a first connector that connects to the node N4 is coupled, and a second terminal connected to the second terminal of the coil C1 at the knot N1 is coupled. The rectifier circuit 50 can be an array of four rectifier transistors T1 , T2 , T3 and T4 exhibit. The transistors T1 , T2 , T3 and T4 can be passively driven field effect transistors with body diodes coupled between the source-drain connections of the transistors (e.g. the transistors T1 , T2 , T3 and T4 form an array of four corresponding diodes). If desired, the transistors can T1 , T2 , T3 and T4 are actively driven in order to carry out active rectification. Passively powered schemes are described herein as an example.

Each of the transistors T1 , T2 , T3 and T4 , has a body diode with terminals coupled to the source of the drains of the transistor. The transistor T1 can be a body diode D1 have in parallel with the transistor switch SW1 is coupled that is open. The transistor T2 can the body diode D2 have in parallel with the transistor switch SW2 is coupled that is open. The transistors T3 and T4 can each have body diodes D3 and D4 have, each in parallel with the open transistor switches SW3 and SW4 are coupled. In a passively powered scheme, the transistors form T1 , T2 , T3 and T4 an array of four respective diodes D1 , D2 , D3 and D4 that are used for rectification.

The adjustable rectifier circuit 50 has transistor T5 on. The transistor T5 can be a body diode D5 include that in parallel with the transistor switch SW5 coupled by one to the gate of the transistor T5 from the control circuit 30th received control signal can be controlled. The source-drain connections of the transistor T5 can each with the knot N1 and the crowd 104 be coupled. The control circuit 30th can the rectifier circuit 50 optionally set to a first mode (sometimes referred to as the vertical field mode or vertical mode) in which the transistor switch SW5 of the transistor T5 is closed) and a second mode (sometimes referred to as the horizontal field mode or horizontal mode) in which the transistor switch SW5 of the transistor T5 is open).

The switch is in vertical mode SW5 closed and forms a short circuit between the node N1 and the crowd 104 , and the diodes D1 , D2 , D3 and D4 (e.g. the transistors T1 , T2 , T3 and T4 ) the adjustable rectifier circuit 50 form two half-bridge rectifiers that are used in parallel. A first half-bridge rectifier is made from the transistors T1 and T2 (Diodes D1 and D2 ), and a second half-bridge rectifier is made from the transistors T3 and T4 (Diodes D3 and D4 ) educated. While operating in vertical mode, current IVP flows from the coils during positive cycles of the received AC wireless signal 48 through the circuit 50 , eliminating the burden 100 is powered. During the negative cycles of the received AC wireless signal in the vertical mode, the current IVN flows and charges the capacitors 72 .

In the horizontal mode the transistor has T5 another state (e.g. is switch SW5 open). When the switch SW5 is open, the diode will D5 between the knot N1 and the crowd 104 switched for use. In this mode the transistors form T1 , T2 , T3 and T4 (Diodes D1 , D2 , D3 and D4 ) the adjustable rectifier circuit 50 a full bridge rectifier. During the positive cycles, the current IHU flows through the rectifier circuit 50 and supplies the load 100 with electricity. During the negative cycles, the current IHN flows through the rectifier circuit 50 and supplies the load 100 with electricity.

Accordingly, the adjustable rectifier circuit 50 can be used to receive magnetic fields in vertical mode (e.g. the coil C1 the field B1 from 3 received and the coil C2 can the field B2 from 3 received) and can, if by the opening switch SW5 reconfigured, can be used to receive magnetic fields in horizontal mode (e.g. the coil C1 the field B1 out 3 received and the coil C2 can the field B2 ' out 3 receive). By allowing the control circuit 30th the state of the rectifier circuit 50 controls (e.g. by controlling the state of the switching circuit such as the switch SW5 of the transistor T5 ), the control circuit can 30th the spools 48 and the rectifier circuit 50 set to handle vertical magnetic fields or horizontal magnetic fields. This enables the circuit 50 is dynamically adjusted to reflect changes in that of the device 24 received magnetic field due to changes in the wireless power signal received from the device 12 is transmitted, or positioning and orientation changes of the devices 12 and 24 To take into account. The adjustability of the rectifier circuit 50 therefore represents the device 24 increased flexibility to accommodate both horizontal and vertical magnetic flux. If desired, allow the inclusion of the coils C1 and C2 into the device 24 that wireless power signals are transmitted to accessory devices. For example, the inverter circuit in the device 24 with the coils C1 and C2 and drive these coils to create out-of-phase magnetic fields (such as horizontal magnetic fields) generated by wireless ear studs or other coils 48 overlapping power receiving devices can be received.

Satisfactory wireless power transmission can be obtained by satisfactorily tuning the wireless power transmission circuitry in the system 8th is ensured. The total inductance for the coils connected in series 48 is 2L , in which L. the inductance of the coil C1 and L. the inductance of the coil C2 is. The effective capacitance of the capacitors 72 is in series C / 2 , in which C. the capacitance of each capacitor 72 is. The resonance frequency ffb for full bridge operation (used in horizontal mode) is thus given by equation 1. $$\text{ffb}=\text{1/}\left[2\mathrm{\pi }{\left(2\text{L * C / 2}\right)}^{1\text{/ 2}}\right]$$

This is the same as the resonance frequency fhb for half-bridge operation (in the vertical mode) given by Equation 2. $$\text{fhb}=\text{1/}\left[2\mathrm{\pi }{\left(\text{L * C}\right)}^{1\text{/ 2}}\right]$$

Since ffb and fhb are the same, the tuning of the rectifier circuit changes 50 not even if the control circuit 30th the rectifier circuit 50 toggles between vertical and horizontal modes, which helps ensure that the device's wireless power receiving circuit 24 not detuned when switching between the two modes.

According to one embodiment, a wireless power receiving device configured to wirelessly receive power in wireless transmission from a wireless power transmitting device is provided that includes first and second coils coupled in series and configured to receive wireless signals, and an adjustable rectifier circuit that includes coupled to the first and second coils and configured to generate DC output signals from the received wireless power signals, wherein the adjustable rectifier is configured to operate in a first mode in which the reconfigurable rectifier circuit forms a full bridge rectifier that operates in a second mode; in which the reconfigurable rectifier circuit forms a pair of parallel half-bridge rectifiers.

In another embodiment, the first and second coils are connected together at a node, the adjustable rectifying circuit including an array of four diodes, capacitors coupled between the array of four diodes and the first and second coils, and a transistor coupled to the node.

According to another embodiment, the wireless power receiving device includes a control circuit configured to control the transistor for adjusting the adjustable rectifier circuit.

According to another embodiment, the control circuit is configured to switch the transistor on and off for switching the adjustable rectifier circuit between the first and second operating modes.

According to another embodiment, the transistor has a first source-drain terminal coupled to the node and a second source-drain terminal coupled to ground.

In another embodiment, the wireless power receiving device includes a display and a housing in which the display is mounted.

In another embodiment, the first and second coils are overlapped in the housing and by the display.

According to another embodiment, in the first mode of operation the adjustable rectifier circuit is configured to use the first coil to receive a magnetic field and to use the second coil to receive a magnetic field that is in phase with the magnetic field received by the first coil is.

According to a further embodiment, the adjustable rectifier circuit is configured in the second operating mode to use the first coil to receive a magnetic field that is out of phase with a magnetic field received by the second coil.

According to another embodiment, the adjustable rectifier circuit in the first mode is configured to conduct current in series through the first and second coils.

In accordance with one embodiment, an electronic device is provided that includes a housing, a display attached to the housing, first and second coils in the housing configured to receive wireless power signals through an adjustable rectifier circuit coupled to the first and second coils a control circuit adapted to adjust the adjustable rectifier circuit between a first configuration in which AC signals are received by the adjustable rectifier circuit from the first coil that are in phase with AC signals received by the adjustable rectifier circuit from the second coil and a second configuration, in which AC signals are received by the adjustable rectifier circuit from the first coil that are out of phase with AC signals received by the adjustable rectifier circuit from the second coil reads.

According to another embodiment, the AC signals received by the adjustable rectifier circuit from the first coil are 180 ° out of phase with the AC signals received by the adjustable rectifier circuit from the second coil during operation in the second embodiment.

In another embodiment, the first and second coils are coupled to a node and the adjustable rectifier circuit includes a switch coupled to the node.

According to another embodiment, the control circuit is for setting the adjustable rectifier circuit by controlling the switch to operate in a selected first state in which the adjustable rectifier circuit forms a full bridge rectifier, and a second state that differs from the first state in which the adjustable Rectifier circuit forms two parallel half-bridge rectifiers configured.

According to another embodiment, the switch has a first state when the adjustable rectifier circuit is in the first configuration and the switch has a second state that is different from the first state when the adjustable rectifier circuit is in the second configuration.

According to another embodiment, the housing includes the housing of a cell phone.

In accordance with one embodiment, an electronic device is provided including first and second coils configured to receive wireless power signals, an adjustable rectifier circuit coupled to the first and second coils and adjustable to operate in a first mode , in which the adjustable rectifier circuit forms a full bridge rectifier, and in a second mode in which the adjustable rectifier circuit forms two parallel half-bridge rectifiers.

In another embodiment, the adjustable rectifier circuit includes a transistor and the electronic device includes a control circuit configured to control the transistor to set the adjustable rectifier circuit between the first and second modes of operation.

In another embodiment, the first and second coils are connected in series at a node and the transistor is coupled to the node.

In another embodiment, the electronic component includes a display.

The foregoing is merely illustrative and various modifications can be made to the described embodiments. The above embodiments can be implemented individually or in any combination.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 16505370 [0001]
• US 62828933 [0001]

Claims (15)

A wireless power receiving device for wirelessly receiving power in wireless power transmission from a wireless power transmission device, comprising: first and second coils connected in series and configured to receive wireless power signals; and an adjustable rectifier circuit coupled to the first and second coils and configured to generate DC output power from the received wireless power signals, the adjustable rectifier circuit configured to: Operating in a first mode in which the reconfigurable rectifier circuit forms a full bridge rectifier; and Operate in a second mode in which the reconfigurable rectifier circuit forms a pair of parallel half-bridge rectifiers. Wireless power receiving device according to Claim 1 wherein the first and second coils are connected together at a node, the adjustable rectifier circuit further comprising: an array of four diodes; Capacitors coupled between the array of four diodes and the first and second coils; and a transistor coupled to the node. Wireless power receiving apparatus according to Claim 2 , further comprising a control circuit configured to control the transistor to adjust the adjustable rectifier circuit. Wireless power receiving apparatus according to Claim 3 wherein the control circuit is configured to turn the transistor on and off to toggle the adjustable rectifier circuit between the first and second modes of operation. Wireless power receiving apparatus according to Claim 4 wherein the transistor has a first source-drain terminal coupled to the node and a second source-drain terminal coupled to ground. Wireless power receiving apparatus according to Claim 4 further comprising: a display; and a case to which the display is attached. Wireless power receiving device according to Claim 6 wherein the first and second coils are in the housing and are overlapped by the display. Wireless power receiving apparatus according to Claim 7 wherein, in the first mode, the adjustable rectifier circuit is configured to use the first coil to receive a magnetic field and to use the second coil to receive a magnetic field that is in phase with the magnetic field received by the first coil. Wireless power receiving apparatus according to Claim 8 wherein, in the second mode, the adjustable rectifier circuit is configured to use the first coil to receive a magnetic field that is out of phase with a magnetic field received by the second coil. Wireless power receiving apparatus according to Claim 1 wherein the adjustable rectifier circuit in the first mode is configured to pass current in series through the first and second coils. An electronic device comprising: a housing; a display attached to the housing; first and second coils in the housing configured to receive wireless signals therethrough; an adjustable rectifier circuit coupled to the first and second coils; and a control circuit configured to set the adjustable rectifier circuit between: a first configuration in which AC signals from the adjustable rectifier circuit are received by the first coil that are in phase with AC signals received from the adjustable rectifier circuit from the second coil; and a second configuration in which AC signals from the adjustable rectifier circuit are received by the first coil that are out of phase with AC signals received from the adjustable rectifier circuit from the second coil. Electronic device according to Claim 11 wherein the AC signals received by the adjustable rectifier circuit from the first coil are 180 ° out of phase with the AC signals received by the adjustable rectifier circuit from the second coil during operation in the second embodiment. Electronic device according to Claim 11 , wherein the first and second coils are coupled to a node and wherein the adjustable rectifier circuit comprises a switch coupled to the node. Electronic device according to Claim 13 wherein the control circuit is configured to adjust the adjustable rectifier circuit by controlling the switch to operate in a selected one of the following: 1) a first state in which the adjustable rectifier circuit forms a full bridge rectifier; and 2) a second state, which differs from the first state, in which the adjustable rectifier circuit forms two parallel half-bridge rectifiers. An electronic device comprising: first and second coils configured to receive wireless power signals; adjustable rectifier circuits coupled to the first and second coils that are adjustable to operate in: 1) a first mode in which the adjustable rectifier circuit forms a full bridge rectifier; and 2) a second mode in which the adjustable rectifier circuit forms two parallel half-bridge rectifiers.

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