Patent Application
20130065088
The present disclosure relates generally to portable electronic devices. More particularly, the present disclosure relates to a method and apparatus for an integrated starter element for a fuel cell in a handheld device.
The use of fuel cells in portable electronic devices (and especially handheld devices, that is, devices sized to be held or carried in a human hand), has been contemplated and is still being researched and developed by various companies and scientists. The opportunity to have a portable electronic device, such as a mobile communication device like a cell phone or smart phone, which does not require a power cord for recharging, can be seen as a greener or more autonomous alternative. However, there are still some issues relating to the use of fuel cells within mobile communication devices which need to be addressed before they find wide-spread acceptance, especially when adapted to work with smaller, handheld devices.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the attached Figures, wherein:
The current disclosure is directed at a method and apparatus starting of a fuel cell within a mobile communication device, which may be useful for (but is not necessarily limited to) emergency starts of a fuel-cell-powered device. In general, an emergency start occurs when there is a rapid or urgent need for power, such as power to make and sustain an emergency communication (such as a 9-1-1 call). In one embodiment, the starting apparatus includes a piezoelectric element, or charger, as an integrated fuel cell starter. By starting the fuel cell, a sustainable or larger energy source becomes available for the handheld device when the main battery is drained.
In a first aspect, the present disclosure provides an apparatus for an integrated fuel cell starting system for a mobile communication device comprising a fuel cell; a fuel cell tank, connected to the fuel cell, for supplying fuel to the fuel cell; a fuel cell starter connected to the fuel cell; and a processor, in communication with the fuel cell starter; wherein when the processor receives an input requesting an emergency start of the fuel cell, the processor transmits a signal to the fuel cell starter to start the fuel cell.
In another aspect, there is provided a method of starting a fuel cell in a mobile communication device comprising receiving a request for emergency start of the fuel cell; transmitting a signal to a fuel cell starter to start a fuel cell; and transmitting power from the fuel cell to power the mobile communication device.
Other aspects and features of the present disclosure will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the disclosure in conjunction with the accompanying figures.
The adaptation of fuel cells to power portable electronic devices in general and to handheld devices in particular presents a number of challenges. One of those challenges pertains to starting the fuel cell. In contrast to conventional batteries, which are typically ready to supply power at once, some fuel cells need to get “started” before they can supply power. In general, starting entails moving fuel from a fuel cell tank—where fuel is stored—to the fuel cell itself. Once in the fuel cell, the fuel undergoes a reaction that generates electricity. The time for a fuel cell to get started need not be very long, but the delay in getting started may be an inconvenience to a user of the portable electronic device. In an extreme scenario, a delay in operation due to starting—even a delay of a matter of a few seconds—may be especially troublesome when a user wishes to make an emergency telephone call, but has to wait for the fuel cell to get started.
Fuel cells may become more difficult to start when they have been idle for long periods of time or when main power sources are drained or unavailable. External conditions such as temperature and humidity can also affect delays in starting. Consequently, a delay in starting may vary from time to time and place to place.
Generally, the present disclosure provides a method and system for an integrated starter for a fuel cell in a handheld, or portable, device, such as a mobile communication device that may be used in emergency situations. Inclusion of a fuel cell within a portable device allows a second power supply, such as a conventional battery or other power sources, to supply power for the portable electronic device as the fuel cell undergoes starting. In an alternative embodiment, the system may be used as an emergency starter when the second power supply is drained.
Turning to
In an illustrative embodiment of the concept, the fuel cell starter 18 includes an energy-generating element. In one implementation, the fuel cell starter 18 includes at least one piezoelectric element (or “piezo”). In a typical variation, the fuel cell starter 18 can include a plurality of piezos. In general, a piezoelectric element can receive movement of a moving part as an input and can generate electric current as an output. In other words, piezos can convert mechanical energy into electrical energy, or vice versa. The piezoelectric element can be quite small and may be integrated into the portable electronic device 10 without significant loss of space for other components. A further potential advantage of a piezoelectric element is that a piezo can produce electric current, and thus electric energy, virtually immediately. The energy generated by the piezo can be harvested or stored in a storage device such as a rechargeable battery 34. Energy generated by the piezo may be directed to the rechargeable battery 34 to compensate for self-discharge or drainage of the rechargeable battery 34, or for later use. The energy generated by the piezo can also be supplied to the fuel cell 14 to start the fuel cell 14 or to initiate a fuel cell starting sequence. The energy generated by the piezo can further be used to activate a heater (not shown in
In the embodiment of
The processor 12 is connected to or in communication with the fuel cell starter 18 to transmit the necessary signals to start the fuel cell 14 once certain operational conditions are met. These operational conditions will be described in more detail below with respect to the flowcharts of
The fuel cell 14 is connected to the fuel tank 16, which supplies the fuel 30, in a liquid or gaseous form, to assist in the generation of electricity by the fuel cell 14. The amount of fuel 30 can be monitored in any of several ways, and the processor 12 can be kept informed of the amount of fuel 30. The flow of fuel from the fuel tank 16 to the fuel cell 14 can be controlled by microfluidics. In general, the fuel cell 14 generates electric energy by a reaction between the fuel 30 and an oxidant. The electricity generated by the fuel cell can then be stored in the rechargeable power supply 20 or employed to supply power to electrical components within the device 10.
The optional DC/DC converter 24 and PMU 22 can be used to assist in regulating the power generated by the fuel cell 14 in accordance with the power requirements of the rechargeable power supply 20 or the device components. As shown in
In embodiments where the output of the fuel cell 14 (and/or other power elements) is used to power the electrical components of the device 10 either directly or through a combination of the DC/DC converter 24 and PMU 22, a condition may arise in which the output of the fuel cell 14 (or the DC/DC converter 24) is less than the power demand of the device components. In such a condition, the processor 12 may determine which device components should receive the available power. In other circumstances, the energy output of the fuel cell 14 may be greater than the energy demand of the device components. In those circumstances, the excess power can be managed via the PMU 22 and the energy output of the fuel cell may be reduced under the control of the processor 12 or the PMU 22.
Turning to
Once the input signal is received, the processor 12 may optionally determine 102 if there is a particular amount of fuel in the fuel tank 16 (or more). As noted previously the amount of fuel in the fuel tank 16 may be regularly monitored. Monitoring of the fuel level need not use very much power. If there is not enough fuel to start the fuel cell, an alarm or alert 103 can be generated by the processor 12. The alert may be manifested to the user in any of several ways, such an audible or visual notification. Additional power management procedures may be taken if the supply of fuel is low, but those are omitted for simplicity. This monitoring 102 of the fuel level can be regularly performed and does not have to be done only when the fuel cell 14 is to be started.
Assuming there is adequate fuel, the processor transmits 104 a start signal to the fuel cell starter 18 to start the fuel cell 14. The start signal controls the fuel cell starter 18. The processor 12 may (substantially contemporaneous with transmission of the start signal) also activate 106 components or effective systems. These effective systems include, but are not limited to, pumps, fans, heaters or a dessicator. Each of these systems can assist in the operation of the fuel cell 14 and fuel tank 16 to maintain or ensure that the fuel cell 14 operates within expected or desired operating conditions. Some of these systems may be of greater importance in the operation of a portable handheld electronic device than in fuel-cell-powered device of a larger scale. Activation of effective systems is optional or may be responsive to the existing circumstances, and in some cases fewer than all effective systems may be activated. As an illustration, if there is an ice buildup on the fuel cell, a heater may be activated; but if there is no ice buildup, it may be unnecessary to activate a heater.
When the fuel cell starter 18 receives the start signal, the starter 18 starts the fuel cell 14. In the embodiment discussed previously, the fuel cell starter includes a piezoelectric element which has generated energy that has been harvested or stored. The piezoelectric element is capable of generating energy when the device 10 is (for example) shaken or vibrated. Although shaking or vibrating may occur during ordinary operation of the portable electronic device 10, additional shaking may be appropriate for a device that has been sitting motionless for an extended period of time. In response to the start signal, the starter 18 supplies energy (which may include energy generated by motion and energy stored in the battery 34) to the fuel cell 14 to initiate a fuel cell starting sequence. In general, initiating the fuel cell starting sequence powers the effective systems to enable the fuel cell 14 to initiate its own energy generation. In a device having multiple fuel cells, each fuel cell 14 may have its own starting sequence, and the fuel cells may be started at different times or at the same time. The processor 12 may monitor the progress of the starting sequence and may determine whether energy is being produced by the fuel cell 14.
If, upon monitoring to determine 110 whether the fuel cell 14 has satisfactorily started and energy is being generated, the fuel cell 14 is determined not to have started, the processor 12 may perform a check to determine 112 if the effective systems were, or ought to be, activated. If the systems were not yet activated, a signal may be transmitted to control activation 114 of these systems or modify the operation of the systems to improve the fuel cell operating conditions. The processor may transmit 108 a new start signal to restart the fuel cell starting sequence. Under some circumstances, the processor 12 can determine 110 whether or not the fuel cell has started, and not try to start the fuel cell 14 again.
If the fuel cell has started, the energy is directed 116 by the processor 12. If the energy generated by the fuel cell 14 is supplied to power electronic components, the energy can be regulated by the power management unit 22 (PMU) or the DC/DC converter 24, or both.
As the starting sequence is in progress, energy for consumption by electronic components of the portable electronic device may be supplied by other sources, such as the battery 20. The processor 12 may control the directing of energy from the battery 20 to the other components. When the fuel cell 14 is started and is generating energy, the processor 12 may control the directing of energy from the fuel cell 14 to the components.
Turning to
After the assessment has been completed, a set of effective systems can be activated 204 by the processer 12. Which (if any) effective systems are activated may be a function of the assessment performed. For instance, if the temperature surrounding the fuel cell 14 is low, a heater can be started to raise the temperature surrounding the fuel cell 14. Even under limited power, the effective systems can often operate to maintain operating conditions for the fuel cell 14, the fuel tank 16 and other device components. The processor 12 transmits a start signal to initiate 206 the fuel cell starter 18 to start or execute the fuel cell starting sequence. After the starting sequence has commenced, a check 208 is performed to determine if the fuel cell 14 has started. If the fuel cell 14 has not started, a check is performed to determine if the effective systems were activated 210. If the systems were not yet activated, they can then be activated 212. The processor 12 may or may not transmit a new start signal.
If the fuel cell has started, then the energy can be directed 214 by the processor 12. Until the fuel cell 14 starts, energy for electronic components of the portable electronic device may be supplied by other sources, such as the battery 20.
The concepts, embodiments and variations described herein may realize one or more advantages. One potential benefit is that fuel cells may become more viable as power supplies for portable electronic devices in general and handheld electronic devices in particular. Fuel cells may provide greater energy storage than conventional batteries and may be replenished less often than conventional batteries. Fuel cells may offer greater efficiency than conventional batteries and less energy leakage. But fuel cells need not always be activated, and so there may be benefits to having them being capable of being deactivated and started. In addition to generating energy that may not be demanded, a fuel cell may produce by-products (such as water) that may be especially undesirable in the context of handheld devices. Further, fuel cells physically move fuel from a storage tank into the fuel cell, a process which involves some passage of time.
One or more of the embodiments described herein may enable convenient and relatively rapid starting or restarting of fuel cells. In a portable electronic device such as a smart phone, a prompt start of the fuel cell may be important in a number of situations in which there may sustained need for energy, such as (but not limited to) the situation in which there a user needs to make an emergency phone call. Various embodiments described herein may enable the user to draw temporarily upon another power supply, such as a rechargeable battery, while the fuel cell is started. As described in various embodiments, the starter may generate and/or harvest power on its own, independent of the other power supply, and may use this energy to start the fuel cell. In some circumstances, a user may be able to start the fuel cell—and thereby obtain energy for a variety of device functions—by shaking the portable electronic device.
Various embodiments of the concept may advantageously enable the starting to be triggered by one or more events. The triggering of starting may be automatic or may be in response to an explicit user command. Further, various embodiments may support a re-start in the event a first starting attempt fails, or may support not starting when that starting would be fruitless or detrimental.
In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments of the disclosure. However, it will be apparent to one skilled in the art that some or all of these specific details may not be required in order to practice the disclosure. In other instances, well-known electrical structures and circuits are shown in block diagram form in order not to obscure the disclosure. For example, specific details are not provided as to whether the embodiments of the disclosure described herein are as a software routine, hardware circuit, firmware, or a combination thereof.
The above-described embodiments of the disclosure are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope of the disclosure, which is defined solely by the claims appended hereto.
