Patent Publication Number: US-11381112-B2

Title: Wirelessly chargeable portable power bank

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application is a Continuation of Ser. No. 16/010,318, filed Jun. 15, 2018, which claims the benefit under 35 USC 119(e) of U.S. Provisional Application No. 62/520,022 filed Jun. 15, 2017, the contents of all of which are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to battery chargers, and more particularly to wireless charging of portable battery chargers. 
     BACKGROUND OF THE INVENTION 
     With the proliferation of portable electronic devices, such as smart phones, demand for longer lasting batteries has increased. As the manufacturers of portable electronic devices move toward integration of the Li-ion batteries in the portable devices and as the number of portable devices with removable rechargeable batteries decline, demand for portable battery chargers, also referred to herein as portable power banks has increased. 
     These power banks, which usually have a relatively high capacity rechargeable battery, enable their users to recharge their phones and other similar devices as needed. However, users may forget to charge their power banks. A need continues to exist for improved power banks. 
     BRIEF SUMMARY OF THE INVENTION 
     A power bank, in accordance with one embodiment of the present invention, includes, in part, a rechargeable battery, a wireless power recovery unit adapted to receive power wirelessly, a battery charging circuit adapted to deliver the power recovered by the power recovery unit to the rechargeable battery, an output interface, and a voltage reconditioning circuit adapted to supply power from the rechargeable battery to the output interface for delivery to an external device. 
     In one embodiment, the wireless power recovery unit includes a multitude of photodiodes adapted to convert a coherent optical signal to electrical power. In one embodiment, the wireless power recovery unit includes an acoustic transducer adapted to convert acoustic waves to an electrical power. In one embodiment, the wireless power recovery unit includes an inductive coupling circuit adapted to convert time varying magnetic flux to electrical power. In one embodiment, the wireless power recovery unit includes an RF power recovery unit adapted to convert an RF signal to electrical power. 
     In one embodiment, the power bank further includes, in part, an input interface adapted to supply power to the power bank via a wired connection. In one embodiment, the power bank further includes, in part, a voltage sensing circuitry adapted to select between the power supplied by the wireless power recovery unit and the power supplied by the input interface. The selected power is supplied to the rechargeable battery. 
     In one embodiment, the power bank further includes, in part, a controller adapted to monitor the rechargeable battery, and a wireless link adapted to receive and transmit information. In one embodiment, the controller is further adapted to notify a user, via a mobile device associated with the user, to cause the power bank to be charged. In one embodiment, the controller is further adapted to receive instructions from a mobile device to cause the power bank to be charged when one or more conditions are satisfied. In one embodiment, the instructions cause the power recovery unit to charge the rechargeable battery if the charge stored in the rechargeable battery is detected as falling below a threshold level. 
     A power bank, in accordance with one embodiment of the present invention, includes, in part, an RF power recovery unit adapted to convert an RF signal to electrical power, and an inductive coupling circuit adapted to convert the power supplied by the RF power recovery unit to a time varying magnetic flux. 
     A power bank, in accordance with one embodiment of the present invention, includes, in part, a wireless power recovery unit adapted to recover power wirelessly, an output interface, and a voltage reconditioning circuit adapted to deliver the recovered power to an external device via the output interface. In one embodiment, the power bank further includes, in part, a controller, and a wireless link adapted to receive and transmit information. In one embodiment, the power bank further includes, in part, an LCD touchscreen. 
     A method of power delivery, in accordance with one embodiment of the present invention, includes, in part, recovering a power wirelessly, delivering the recovered power to a rechargeable battery, conditioning a voltage received from the rechargeable battery, and supplying the conditioned voltage to an output interface for delivery to an external device. In one embodiment, the power is recovered by a multitude of photodiodes adapted to convert a coherent optical signal to electrical power. In one embodiment, the power is recovered by an acoustic transducer adapted to convert acoustic waves to an electrical power. In one embodiment, the power is recovered by an inductive coupling circuit adapted to convert time varying magnetic flux to electrical power. In one embodiment, the power is recovered by an RF power recovery unit adapted to convert an RF signal to electrical power. 
     In one embodiment, the method further includes, in part, supplying the power to the rechargeable battery via a wired connection. In one embodiment, the method further includes, in part, selecting between the recovered power and the power supplied by the wired connection, and delivering the selected power to the rechargeable battery. 
     In one embodiment, the method further includes, in part, monitoring a status of the rechargeable battery, and wirelessly communicating the status. In one embodiment, the method further includes, in part, notifying a user via a mobile device associated with the user to cause the rechargeable battery to be charged. In one embodiment, the method further includes, in part, transmitting instructions wirelessly to cause the rechargeable battery to be charged when one or more conditions are satisfied. In one embodiment, the condition defines a voltage level of the rechargeable battery. 
     A method of power delivery, in accordance with one embodiment of the present invention, includes, in part, converting an RF signal to electrical power, and converting the electrical power to a time varying magnetic flux. 
     A method of power delivery, in accordance with one embodiment of the present invention, includes, in part recovering a power received wirelessly, and delivering the recovered power to an external device via an output interface. In one embodiment, the method further includes, in part, controlling the recovery of the received power via instructions transmitted wirelessly. 
     A power bank, in accordance with one embodiment of the present invention, includes, in part, a rechargeable battery, an input interface, a battery charging circuit adapted to deliver a power received from the input interface to the rechargeable battery, an output interface, a voltage reconditioning circuit adapted to supply power from the rechargeable battery to the output interface for delivery to an external device, a programmable controller coupled to the battery charging circuit and the voltage conditioning circuit, and a wireless communications link adapted to transmit data to or receive data from an external portable device. 
     A method of power delivery, in accordance with one embodiment of the present invention, includes, in part, receiving power from a wired input interface, delivering the received power to a rechargeable battery, conditioning a voltage received from the rechargeable battery, supplying the conditioned voltage to an output interface for delivery to an external device, monitoring a status of the rechargeable battery, and wirelessly communicating the status. 
     In one embodiment, the method further includes, in part, notifying a user via a mobile device associated with the user to cause the rechargeable battery to be charged. In one embodiment, the method further includes, in part, transmitting instructions wirelessly to cause the rechargeable battery to be charged when one or more conditions are satisfied. In one embodiment, the condition defines a voltage level of the rechargeable battery. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a simplified high-level block diagram of a power bank adapted to be wirelessly charged, in accordance with one embodiment of the present invention. 
         FIG. 2  is a simplified high-level block diagram of a power bank adapted to be wirelessly charged, in accordance with one embodiment of the present invention. 
         FIG. 3  is a simplified high-level block diagram of a power bank adapted to be wirelessly charged, in accordance with one embodiment of the present invention. 
         FIG. 4  is a simplified high-level block diagram of a power bank adapted to be wirelessly charged, in accordance with one embodiment of the present invention. 
         FIG. 5  is a simplified high-level block diagram of a power bank adapted to be wirelessly charged, in accordance with one embodiment of the present invention. 
         FIG. 6  is a simplified high-level block diagram of a power bank adapted to be wirelessly charged, in accordance with another embodiment of the present invention. 
         FIG. 7  is a simplified high-level block diagram of a power bank, in accordance with another embodiment of the present invention. 
         FIG. 8  is a simplified high-level block diagram of a power bank, in accordance with another embodiment of the present invention. 
         FIG. 9  is a simplified high-level block diagram of a power bank, in accordance with another embodiment of the present invention. 
         FIG. 10  is a simplified high-level block diagram of a power bank, in accordance with another embodiment of the present invention. 
         FIG. 11  is a simplified high-level block diagram of a power bank, in accordance with another embodiment of the present invention. 
         FIG. 12  is a simplified high-level block diagram of a power bank, in accordance with another embodiment of the present invention. 
         FIG. 13  is simplified high-level block diagram of a battery charging circuitry, in accordance with another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In accordance with one embodiment of the present invention, a power bank is wirelessly charged. In the following description, it is understood that elements/components identified using the same reference number are identical in structure and operation. 
       FIG. 1  is a simplified high-level block diagram of a power bank  100  adapted to be wirelessly charged, in accordance with one embodiment of the present invention. Power bank  100  is shown as including, in part, an interface  102 , a voltage reconditioning circuit  104 , a rechargeable battery  110 , a battery charging circuit  120 , and a wireless power recovery unit  115 . 
     Interface  102  is adapted to couple battery pack  100  to a device to be charged any may be, for example, a USB interface/port. Voltage conditioning circuit  104  is adapted to condition the power delivered to interface  102  by battery  110 . Battery  110  may be a Li-ion battery. 
     Battery  110  is charged via a DC voltage that battery  110  receives from wireless power recovery unit  115  through battery charging circuitry  120 . Wireless power recovery unit  115  is adapted to convert the power it receives wirelessly to a DC voltage. Battery charging circuitry  120  is adapted to charge battery  110  using the DC voltage supplied by power recovery unit  115 . 
       FIG. 2  is a simplified high-level block diagram of a power bank  150  adapted to be wirelessly charged, in accordance with one embodiment of the present invention. Power bank  150  is shown as including, in part, an interface  102 , a voltage reconditioning circuit  104 , a rechargeable battery  110 , a battery charging circuit  120 , and one or more photodiodes  140 . 
     Interface  102  and voltage reconditioning circuit  104  operate as described above with reference to  FIG. 1 . Photodiodes  140  are adapted to convert a coherent optical signal, such as a laser beam, to a DC voltage. Battery charging circuitry  120  is adapted to charge battery  110  using the DC voltage it receives from photodiodes  140 . To receive charge, a device is plugged into power bank  150  via interface  102 . 
       FIG. 3  is a simplified high-level block diagram of a power bank  175  adapted to be wirelessly charged, in accordance with one embodiment of the present invention. Power bank  175  is shown as including, in part, an interface  102 , a voltage reconditioning circuit  104 , a rechargeable battery  110 , a battery charging circuit  120 , and an acoustic transducer  145 . 
     Interface  102  and voltage reconditioning circuit  104  operate as described above with reference to  FIG. 1 . Acoustic transducer  145  is adapted to convert acoustic and pressure waves to a DC voltage. Battery charging circuitry  120  is adapted to charge battery  110  using the DC voltage it receives from acoustic transducer  145 . 
       FIG. 4  is a simplified high-level block diagram of a power bank  180  adapted to be wirelessly charged, in accordance with one embodiment of the present invention. Power bank  180  is shown as including, in part, an interface  102 , a voltage reconditioning circuit  104 , a rechargeable battery  110 , a battery charging circuit  120 , and an inductive coupling circuit  155 . 
     Interface  102  and voltage reconditioning circuit  104  operate as described above with reference to  FIG. 1 . Inductive coupling circuit  155  is adapted to receive a time-varying magnetic flux and generate a DC voltage in response. Battery charging circuitry  120  is adapted to charge battery  110  using the DC voltage it receives from inductive coupling circuit  155 . 
       FIG. 5  is a simplified high-level block diagram of a power bank  185  adapted to be wirelessly charged, in accordance with one embodiment of the present invention. Power bank  185  is shown as including, in part, an interface  102 , a voltage reconditioning circuit  104 , a rechargeable battery  110 , a battery charging circuit  120 , and RF power recovery unit  165 . 
     Interface  102  and voltage reconditioning circuit  104  operate as described above with reference to  FIG. 1 . RF power recovery unit  165  is adapted to receive and convert the received RF signal to a DC voltage. Battery charging circuitry  120  is adapted to charge battery  110  using the DC voltage it receives from RF power recovery unit  165 . 
       FIG. 6  is a simplified high-level block diagram of a power bank  190  adapted to be wirelessly charged, in accordance with another embodiment of the present invention. Wireless power recovery unit  190  may be any one of, or a combination of one or more of RF power recovery unit  165  shown in  FIG. 5 , photodiodes  140  shown in  FIG. 2 , acoustic transducer  145  shown in  FIG. 3  and/or inductive coupling circuitry  155  shown in  FIG. 4 . Power bank  190  is also shown as including, in part, an input interface  195  (e.g., a USB interface) adapted to be plugged into a power source to charge battery  110  via battery charging circuit  120 . 
     Battery charging circuit  120  is shown as including a voltage sensing circuitry (VSC)  122  adapted to compare the amount of voltage received from interface  195  and wireless power recovery unit  190  and select one of these voltages for charging of battery  100 . For example, if VSC  122  determines that the amount of power supplied by wired interface  195  is greater than and/or more stable than the amount of power supplied by wireless recovery unit  190 , VSC  122  causes battery  110  to be charged via the voltage received from interface  195 . In one embodiment, voltage sensing circuitry may be formed by a multitude of diodes connected in parallel. 
       FIG. 7  is a simplified high-level block diagram of a power bank  200 , in accordance with another embodiment of the present invention. Power bank  200  includes an output interface  102 , a voltage conditioning circuit  104 , a rechargeable battery  110 , a battery charging circuit  120 , and an input interface  195 , as was described above. Power back  200  is also shown as including, in part, a micro-controller (MCU) and a wireless link  205 , that may conform to any communications standards such as Bluetooth, Wi-Fi, and the like. 
     An application (not shown) running, for example, on the user&#39;s cell phone (not shown), smart watch (not shown), and the like, is wirelessly linked to power bank  200 —via micro-controller (MCU) and wireless link  205 —to enable the user to monitor the status of charging of power bank  200 . For example, information about the charge level, temperature, and the like, may be monitored by the user on another device associated with the user (e.g., his cell phone) and which is wirelessly linked to the power bank via (MCU) and wireless link  205 . Such an application may also be used to set a trigger level for charging of the power bank. For example, the user, using the application on his cell phone or smart watch, may set a trigger level of 30% so that when the stored charge in battery  110  falls below 30%, the user is notified to plug in the power bank  100  to, e.g. a USB complaint outlet via USB port  195  to recharge it. In addition to the charge level, the user may also select the time and/or location for the charging of the power bank through the application. For example, the user may select options that cause the application to notify the user to charge the power bank depending on one or more of the following conditions (i) if he/she is at, e.g., home (specific location), and/or (ii) after, e.g., 9 pm (specific time); and/or (iii) the power bank has, e.g., less than 50% charge. The notification thus reminds the user to recharge the power bank at a selected time and place that is convenient and when the charge level falls below a level selected by the user. 
       FIG. 8  is a simplified high-level block diagram of a power bank  210 , in accordance with another embodiment of the present invention. Power bank  210  includes an output interface  102 , a voltage conditioning circuit  104 , a rechargeable battery  110 , a battery charging circuit  120 , an input interface  195 , and a wireless power recovery circuit  190 . Wireless power recovery unit  190  may be any one of, or a combination of one or more of RF power recovery unit  165  shown in  FIG. 6 , photodiodes  140  shown in  FIG. 2 , acoustic transducer  145  shown in  FIG. 3  and/or inductive coupling circuitry  155  shown in  FIG. 4 . Power back  200  is also shown as including, in part, a micro-controller (MCU) and a wireless link  205 , adapted to conform to any communications standards such as Bluetooth, Wi-Fi, and the like. 
     An application (not shown) running, for example, on the user&#39;s cell phone (not shown), smart watch (not shown), and the like, is wirelessly linked to power bank  200 —via micro-controller (MCU) and wireless link  205 —to enable the user to monitor the status of charging of power bank  200 . For example, information about the charge level, temperature, and the like may be monitored by the user on another device associated with the user (e.g., his cell phone) and which is wirelessly linked to the power bank via (MCU) and wireless link  205 . Such an application may also be used to set a trigger level for charging of the power bank. For example, the user, using the application on his cell phone or smart watch, may set a trigger level of 25% so that when the stored charge of the battery  110  falls below 25%, either the user is notified to plug in the power bank  100  to a power outlet via, e.g., USB port  195  to recharge it. Alternatively, under such conditions, power bank  210  is configured to activate wireless power recovery unit  190  to charge the battery. If the amount of power received by wireless recovery unit  190  is detected to be below a minimum predefined threshold value, the user may be notified to plug the power bank into an outlet via USB port  195 . 
     In addition to the charge level, the user may also select the time and/or location for the charging of the power bank through the application. For example, the user may select options that cause the application either to notify the user to charge the power bank, depending on one or more of the following conditions (i) if he/she is at, e.g., home (specific location), and/or (ii) after, e.g., 9 pm (specific time); and/or (iii) the power bank has, e.g., less than 50% charge. The notification thus reminds the user to recharge the power bank at a selected time and place that is convenient and when the charge level falls below a level selected by the user. The user may also select option via his/her cell phone or smart watch to cause the battery to be charged by wireless power recovery unit  190  if, for example, the battery charge level falls below a first threshold value, and the amount of wireless power being received wirelessly is detected as being greater than a second threshold value. 
       FIG. 9  is a simplified high-level block diagram of a power bank  250 , in accordance with another embodiment of the present invention. Power bank  210  is shown as including a wireless power recovery circuit  190 . Wireless power recovery unit  190  may be any one of, or a combination of one or more of RF power recovery unit  165  shown in  FIG. 5 , photodiodes  140  shown in  FIG. 2 , acoustic transducer  145  shown in  FIG. 3  and/or inductive coupling circuitry  155  shown in  FIG. 4 . 
       FIG. 10  is a simplified block diagram of one exemplary embodiment of power bank  250 . Power bank  250  is shown as including an RF power recovery unit  165  and an inductive charging circuit/unit  155 , but does not include a rechargeable battery. Power bank  250  may receive power from RF signals via RF power recovery unit  165  and deliver the received power to activate inductive charging unit  155 . A portable device, such as a cell phone, smart watch, and the like adapted to be inductively charged and resting on a charging pad that includes the inductive charging unit  155  may thus be charged by power bank  190 . 
       FIG. 11  is a simplified high-level block diagram of a power bank  260 , in accordance with another embodiment of the present invention. Power bank  260  is shown as including a wireless power recovery circuit  190 , a voltage reconditioning circuit  104  and an interface, such as a USB interface. Wireless power recovery unit  190  may be any one of, or a combination of one or more of RF power recovery unit  165  shown in  FIG. 5 , photodiodes  140  shown in  FIG. 2 , acoustic transducer  145  shown in  FIG. 3  and/or inductive coupling circuitry  155  shown in  FIG. 4 . Power bank  260  is adapted to receive, for example, power from RF signals via RF power recovery unit  220  and deliver the received power to a portable device, such as a cell phone that is plugged into, e.g., USB port  102 . Voltage reconditioning circuit  104  converts the DC voltage supplied by RF recovery unit  220  to the format required by USB port  102 . 
       FIG. 12  is a simplified high-level block diagram of a power bank  300 , in accordance with another embodiment of the present invention. Power bank  300  is shown as including a wireless power recovery circuit  190 , a voltage reconditioning circuit  104 , an interface, such as a USB interface  102 , a micro-controller (MCU) and a wireless link  205 , that may conform to any communications standards such as Bluetooth, Wi-Fi, and the like, and an LCD screen  290  that may be a touch screen. 
     Wireless power recovery unit  190  may be any one of, or a combination of one or more of RF power recovery unit  165  shown in  FIG. 5 , photodiodes  140  shown in  FIG. 2 , acoustic transducer  145  shown in  FIG. 3  and/or inductive coupling circuitry  155  shown in  FIG. 4 . Power received by wireless power recovery unit  190  is conditioned by voltage reconditioning circuit  104  and supplied to wired interface (e.g., USB port)  102 . MCU and wireless link  205  operate in the same manner as described above with reference to  FIGS. 6 and 7 . 
     Power bank  300  may be provided by a service provider, such as restaurant or a coffee shop, to a user sitting at the restaurant or the coffee shop. The LCD may be used by the user, for example, to place an order. Alternatively, the service provider may provide information to the user via the LCD screen. For example, if the service provider is a restaurant at an airport, it may provide the user/customer with flight information. The user/customer may also use power bank  300  to charge a portable device by, for example, plugging his/her portable device into USB port  102 . Power bank  300  is adapted to receive power via power recovery unit  190 , as described above with reference to  FIGS. 10 and 11 . 
       FIG. 13  is a number of components of battery charging circuitry  120  described in any of the above embodiments. The voltage that is provided by the wireless power recovery unit  115  may not be sufficient to charge a lithium-ion battery. Moreover, wireless power recovery unit  115  operates more efficiently and provides a higher output power when its output load has an optimum value. The optimum load and the current drawn from power recovery unit  115  may depend on the power incident on power recovery unit  115  and hence the load, in accordance with one embodiment of the present invention, is dynamically adjusted. 
     As described further below, battery charging circuitry  120  is adapted to increase the voltage supplied by power recovery unit  115  to match that of the battery. Switch controller  320  is adapted to close one of the switches  305  or  310  at any given time. Therefore, when controller  320  closes switch  305 , it opens switch  310 . Conversely, when controller  320  open switch  305 , it close switch  310 . 
     When switch controller  320  closes switch  305  and opens switch  310 , because the current flowing from power recovery unit to inductor  300  cannot increase instantaneously, the current in the inductor starts to increase. The current increase in the inductor continues until switch controller  320  open switch  305  and closes switch  310 . When switch  310  closes the current stored in inductor  300  is enable to charge the battery after flowing through voltage and current sensing block  315 . Therefore, by changing the duty cycle of the current pulses supplied to the battery through opening and closing of switches  305  and  310 , the average current and hence the time it takes to charge the battery is optimized. Block  315  is adapted to sense the current being delivered to the battery and/or sense the voltage stored the battery. The current and/or voltage so sensed by block  315  are also delivered to controlling logic  330 . In response, controlling logic controls the width of the pulses that pulse-width modulator (PWM) block  325  generates and applies to switches  305  and  310 . In other words, through the feedback mechanism shown in  FIG. 13 , the width of the pulses applied to switches  305  and  310 , and hence the duty cycle of the current pulses supplied to the battery is maintained at an optimum level while ensuring that the battery is not over charged. 
     The above embodiments of the present invention are illustrative and not limitative. The embodiments of the present invention are not limited by the number of transmitting elements or receiving elements. The above embodiments of the present invention are not limited by the wavelength or frequency of the signal. The above embodiments of the present invention are not limited by the type of circuitry used to charge a battery or to condition the voltage supplied by a battery. The above embodiments of the present invention are not limited by the number of semiconductor substrates that may be used to form the power bank. Other modifications and variations will be apparent to those skilled in the art and are intended to fall within the scope of the appended claims.