The present invention relates to a system and method for providing a compact and mobile source of electrical power for recharging a mobile electronic device.
Personal mobile electronic devices are in widespread use by consumers. Most such devices operate on an internal rechargeable power source, rather than a disposable battery, and thus require periodic access to an AC charging device. Such AC charging devices typically comprise a transformer that is plugged into an AC power outlet, and a DC output cord with a plug that is connected to the charging port of the device.
However, there are times when the mobile device may be low on electrical power, or has been completely discharged, and the conventional AC charging device has been misplaced or is not otherwise available. In some situations, the user of the mobile electronic device may be in a foreign country, and does not have an AC charging device configured for operation from a local electrical power socket.
What is needed is an apparatus and method for recharging a mobile electronic device when the device AC charger is not available or is incompatible with a locally-available electrical power outlet.
In one aspect of the present invention, a charging device comprises: a DC-to-DC converter for converting electrical power obtained from a battery source into a charging current for transmission to an electronic device; a voltage latch electrically connected to the DC-to-DC converter, the voltage latch for controlling the DC-to-DC converter so as to mitigate oscillation in the battery source; and an output current control electrically connected to the DC-to-DC converter, the output current control for regulating the charging current transmitted to the electronic device.
In another aspect of the present invention, a charging device comprises: a DC-to-DC converter for converting electrical power obtained from a battery source into a charging current for transmission to an electronic device, the DC-to-DC converter including a first microcircuit functioning as a step-down DC-to-DC regulator; a voltage latch electrically connected to the DC-to-DC converter, the voltage latch including a second microcircuit configured as a comparator; and an output current control electrically connected to the DC-to-DC converter, the output current control including a third microcircuit functioning as a current sense monitor.
In still another aspect of the present invention, a method for recharging a rechargeable electronic device comprises: obtaining a DC-to-DC converter, a voltage latch electrically attached to the DC-to-DC converter, and an output current control connected to an output of the DC-to-DC converter; electrically connecting a battery source to an input of the DC-to-DC converter; and electrically connecting the output current control to the rechargeable electronic device.
The additional features and advantage of the disclosed invention is set forth in the detailed description which follows, and will be apparent to those skilled in the art from the description or recognized by practicing the invention as described, together with the claims and appended drawings.
The foregoing aspects, uses, and advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when viewed in conjunction with the accompanying figures, in which:
The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention.
The disclosed compact charging device includes a DC-to-DC convertor that can be adapted for a variety of input voltages, as provided by a suitable battery source, and output voltages, as required by a particular mobile electronic device. The disclosed compact charging device can easily be carried on a user's person, or attached to a keychain, and can make use of readily available battery power sources to recharge the mobile electronic device.
There is shown in
The DC-to-DC converter 12 in the charging device 10 may output a charging voltage of VL to a mobile electronic device 30 via a pair of output leads 32. It should be understood that, while the disclosed charging device 10 may be particularly suitable for use with the mobile electronic device 30, the present invention is not limited to use with mobile electronic devices, and can be configured to operate with essentially any electronic device powered with an internal rechargeable power source. The output current control 14 functions to regulate the amount of charging current transmitted to a rechargeable battery (not shown) in the mobile electronic device 30. In an exemplary embodiment, the charging device 10 may be configured to provide a charging voltage, within a pre-specified range of voltages, to a SMARTPHONE, an ANDROID, an IPHONE, a BLACKBERRY, an ITOUCH, various types of Wi-Fi mobile devices, and various types of TABLETS, such as an IPAD.
In an exemplary embodiment, the output voltage VL may be about five volts for most mobile electronic devices, and may be a voltage level other than five volts for products manufactured by Apple Corporation, for example. As can be appreciated by one skilled in the art, the optimal current level provided by the charging device 10 may vary from one device to another. Accordingly, the output current control 14 may be configured so as to provide an optimal charge current for a specific mobile electronic device. It can be appreciated by one skilled in the relevant art that the specific components and component values used in the charging device 10 are a function of the input voltage VB and the output voltage VL.
In an exemplary embodiment, shown in
The battery indicator circuit 46 may be electrically connected between the DC-to-DC converter 12 and the output current control 14 to provide an indication, via the indicator light 48, as to the status of the charging operation. In an exemplary embodiment, the indicator light 48 illuminates while the battery source 20 is charging the mobile electronic device 30. When the indicator light 48 ceases illumination, this condition may serve to inform the user that the installed battery source 20 has been depleted. Accordingly, the depleted battery source 20 can be removed and replaced with another battery source 20, if the rechargeable battery in the mobile electronic device 30 has not been fully recharged. The replacement battery source 20 can be electrically connected to the charging device 40 so as to continue or complete the recharging process.
In an exemplary embodiment, shown in
The miniature snap terminals 52a, 52b may be used, for example, when the battery source 20 comprises a nine-volt battery in accordance with ANSI-1604A or IEC-6LR61 standards. A nine-volt battery based on a zinc-magnesium dioxide chemical system can provide a charge of from about 300 mAh (at a discharge rate of 500 to 1000 mA). A plurality of “AA” batteries may also be used, in place of the nine-volt battery, where each AA battery can provide a charge output of about 1.5 volts at about 2500 mAh. It should be understood that, if AA batteries are used, battery terminals (not shown) other than the snap terminals 52a, 52b could be used on the device housing, or an adapter (not shown) could be electrically connected between the snap terminals 52a, 52b and a battery holder containing the AA batteries. It can be appreciated by one skilled in the art that a typical mobile electronic device 30 may require a charging current of about 500 mA at a charge level of about five-volts.
In an exemplary embodiment, the electronic device connector 54 may comprise a micro-USB connector adapted to mate with the micro-USB receptacle in a SMARTPHONE, for example. In an alternative embodiment, the electronic device connector 54 may comprise a 30-pin, I/O plug with latches, when the charging device 50 is configured for use with one or more products manufactured by the Apple Corporation.
Use of the charging devices 10, 40, 50 with the mobile electronic device 30 may be described with reference to a flow diagram 60, in
The optional ESD protection component 42 may also be mounted on the substrate if desired, at step 64. The optional reverse voltage protection component 44 may also be included in the charging device circuit, at step 66. The optional battery indicator circuit 46 may be integrated into the circuit on the substrate, at step 68. The set of miniature snap terminals 52a, 52b may be electrically attached to the substrate at the input side of the charging circuit, at step 70.
The battery source 20 may be attached directly to the charging circuit, or to the set of miniature snap terminals 52a, 52b, at step 72, so as to provide electrical power to the DC-to-DC converter 12. The appropriate electronic device connector 54 may be selected for compatibility with the mobile electronic device 30, and electrically attached to the output leads 32, at step 74. A housing 92 (see
As can be appreciated by one skilled in the art, the charging devices 10, 40, 50 are thus (i) small and compact for placement on a user's keychain, for example, when enclosed in an appropriate housing, such as shown in
In an exemplary embodiment, the DC-to-DC converter 12, shown in
In an exemplary embodiment, the voltage latch 16, shown in
The microcircuit U3, here shown as a five-volt regulator, functions to convert a voltage (VIN) at the input voltage VB level (e.g., nine volts) into a voltage (VOUT) at the output voltage VL level (e.g., five volts). The delay timer 18 functions to impose a time delay before the output voltage (VOUT) of the microcircuit U3 is provided to the microcircuit U2 in the voltage latch 16. In an exemplary embodiment, a delay timer microcircuit (U5), or equivalent electronic components, may be used in the delay timer 18 to enable a time interval delay of about 0.5 seconds. The microcircuit U5 may comprise a 74LVC2G14 dual-inverting Schmidt trigger with five-volt tolerant inputs, such as may be available from NXP Semiconductors of San Jose, Calif. As described above, the Schmidt trigger component may function to selectively disable the EN (enable) pin on the DC-to-DC converter 12 for the pre-determined period of time set by the delay timer 18 time delay.
Under some operating conditions, when a battery is inserted into battery terminals, such as the miniature snap terminals 52a, 52b, the physical action may generate electrical noise that causes voltage converter microcircuit U1 in the DC-to-DC converter 12 to latch “OFF.” The purpose of the delay timer 18 is to protect the DC-to-DC converter 12 against such electrical noise by providing an initial time interval during which the enable port (EN) on the voltage converter microcircuit U1 is disabled, and consequently, will not respond to electrical noise as an input signal. The delay timer 18 may be reset after the bleeder resistor 24 has caused a discharge of capacitors C1 and C7 in the DC-to-DC converter 12.
In an exemplary embodiment, the battery indicator 46, shown in
The reverse voltage protection component 44 may comprise a p-channel FET on the input line 82, as shown in
In an exemplary embodiment, any of the compact charging devices 10, 40, 50 may be fabricated on a suitable substrate or circuit board (not shown) and enclosed in the housing 92, shown in
It can be appreciated that the configuration of the housing 92 physically retains the battery source outside the housing 92. That is, the housing 92 does not include a battery compartment. Accordingly, because ambient air can provide cooling to the battery source, the heat buildup in the battery source is at a lesser rate than if the battery source were enclosed in a battery compartment. This feature allows the user to remove the battery source from the set of miniature snap terminals 52a, 52b when the battery indicator light 48 goes out, allow the battery source to cool, and then re-install the battery source to more completely drain off any charge that may be remaining in the battery source.
The electronic device connector 54, here configured as a micro-USB connector, extends from one end of the charge key device 90, and is thus accessible to allow for insertion into a charge port of the mobile electronic device 30. An optional cap (shown in
An opening 94 may be provided in the charge key device 90 to allow for attachment to a key ring, for convenient access by a user. In an alternative embodiment, shown in
It should be understood that the present invention is not limited to a housing 92, shown in
It can be appreciated that the electronic components used in any of the charging devices 10, 40, 50 can be mounted to a substrate of essentially any shape and configuration, limited only by circuitry requirements. Preferably, the charging device battery connectors and electronic device connector are positioned on the substrate or circuit board so as to allow a user external access to the battery connectors, so as to retain the battery outside the device housing, and so as to allow the charging device user to access the electronic device connector for insertion into an electronic device.
It can be appreciated that the electronic component substrate used for any of the charging devices 10, 40, 50 may be enclosed in a housing of essentially any size and shape, as may be envisioned by a product designer. For example, the sizes and shapes available for housing miniature external hard drives, commonly referred to as “thumb” drives or “travel” drives, can be adapted for use with any of the charging devices 10, 40, 50. A miniature external hard drive similarly includes a protruding or retractable electronic device connector, such as a USB connector, and is similar in size to any of the charging devices 10, 40, 50. Accordingly, the array of housing designs adapted for use with miniature external hard drives may be appropriated for use with any of the charging devices 10, 40, 50.
It is to be understood that the description herein is exemplary of the invention only and is intended to provide an overview for the understanding of the nature and character of the disclosed illumination systems. The accompanying drawings are included to provide a further understanding of various features and embodiments of the method and devices of the invention which, together with their description serve to explain the principles and operation of the invention.
The present Application is related to Provisional Patent Application entitled “COMPACT MOBILE ELECTRONIC DEVICE CHARGER,” filed 18 Jul. 2011 and assigned filing Ser. No. 61/509,104, incorporated herein by reference in its entirety.
Number | Date | Country | |
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61509104 | Jul 2011 | US |