Power source selection control

A system and method for power source selection control. Multiple power sources of a power supply unit are each connected to a high power load via a plurality of switching circuitries each comprising at least one pair of transistors connected in a common source configuration and positioned between a positive lead of a respective one of the power sources and the high power load. A controller detects presence of a current flow from at least one of the power sources and accordingly selects one of power sources and activates a respective one of the plurality of switching circuitries for conducting a current flow from the respective power source selected to the high power load.

FIELD AND BACKGROUND OF THE INVENTION

Some embodiments described in the present disclosure relate to power supply control and, more specifically, but not exclusively, to power source selection control.

Electrically powered devices using and/or provided with multiple, possibly heterogeneous power sources utilized singly and/or in combination for energy supply to the respective device when in operation, have become more and more ubiquitous in recent years in various fields and applications.

One prominent example where usage of multiple power sources is particularly prevalent is in the case of portable and/or mobile electronic devices, electrically driven vehicles, and/or likewise systems, where stand-alone energy supply independent of the mains power lines may be required in the course of normal operation.

In many such devices, one or more of the power sources may be a rechargeable power source and/or energy reservoir, such as a battery and/or the like, optionally internally residing in the device and inaccessible to direct contact by users.

In some cases, a rechargeable internal battery of this sort must first be charged by an external power supply and/or charger, before the device itself can be used. The power supply may typically provide direct current (DC) or alternative current (AC) voltage, optionally through a special connector, to the device, whereas batteries and/or likewise rechargeable power sources may provide DC or voltage. Once charging is complete or reached a sufficient level, the power supply can then be disconnected, and the device will continue to run for a short period of time until the battery is depleted. Exemplary devices of this sort include for example electric cars, shaving machines, medical laser devices, rechargeable power tools etc.

In other cases, the device may be interchangeably used with either one of two or more power sources, for example, the device may be plugged in and/or connected via a power outlet to the mains electricity power line and/or other likewise AC/DC power source such as an electric generator and/or the like and operate for some time using the external power supply thus provided, and may be unplugged and/or disconnected from external energy sources at other times, relying on its internal rechargeable power source(s) and energy stored therein, either at a pre-charging phase and/or during powering by an external power source, such as a mains power line and/or the like.

SUMMARY OF THE INVENTION

It is an object of the present disclosure to describe a system and a method for power source selection control.

According to one aspect of some embodiments of the disclosed subject matter there is provided a system for power source selection control, comprising: at least one controller adapted to be in connection with: a plurality of power sources of a power supply adapted for providing a current flow to a high power load via at least one of the plurality of power sources, and a plurality of switching circuitries corresponding to the plurality of power sources, wherein each of the plurality of switching circuitries comprising at least one pair of transistors connected in a common source configuration and positioned between a positive lead of a respective one of the plurality of power sources and the high power load; the at least one controller being further adapted for: detecting presence of a current flow from at least one of the plurality of power sources; and in response to the detecting, selecting a respective power source of the plurality of power sources and activating a respective one of the plurality of switching circuitries for conducting a current flow from the respective power source selected to the high power load.

According to another aspect of some embodiments of the disclosed subject matter there is provided a method for power source selection control, comprising: having connection with: a plurality of power sources of a power supply adapted for providing a current flow to a high power load via at least one of the plurality of power sources, and a plurality of switching circuitries corresponding to the plurality of power sources, wherein each of the plurality of switching circuitries comprising at least one pair of transistors connected in a common source configuration and positioned between a positive lead of a respective one of the plurality of power sources and the high power load; by at least one controller connected to the plurality of power sources and controlling the plurality of switching circuitries, performing: detecting presence of a current flow from at least one of the plurality of power sources; and in response to the detecting, selecting a respective power source of the plurality of power sources and activating a respective one of the plurality of switching circuitries for conducting a current flow from the respective power source selected to the high power load.

Optionally, each of the plurality of switching circuitries comprising a voltage converter connected to the at least one controller and adapted for driving the pair of transistors.

Optionally, the plurality of power sources are each connected to a common ground.

Optionally, for each of the at least one controller, a respective power supply channel to a respective one of the at least one controller is electrically disconnected from each of the plurality of power sources.

Optionally, at least one energy reservoir is connected to at least one of the plurality of power sources and adapted for providing a current flow to the at least one controller during transition between one of the plurality of power sources to another occurred in response to the selecting.

Optionally, the plurality of power sources comprising at least one of a direct current power source and an alternating current power source.

Optionally, at least one charging circuitry is connected to at least one pair of the plurality of power sources comprising a rechargeable power source and adapted for charging the rechargeable power source using a current flow from at least one other power source of the at least one pair.

Optionally, the at least one pair of transistors comprising at least one pair of metal-oxide-semiconductor field-effect transistors.

Optionally, a pair of transistors in the at least one pair are serially connected and oppositely disposed relative to one another.

Optionally, the at least one pair of transistors comprising at least one of a pair of N-channel field-effect transistors and a pair of P-channel field-effect transistors.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

Some embodiments described in the present disclosure relate to power supply control and, more specifically, but not exclusively, to power source selection control.

One technical challenge dealt with by the disclosed subject matter is to allow for selecting a single power source out of multiple power sources to provide high power to a system containing one or more control modules and a high load, in a streamlined and fail-safe manner. When such selection takes place and/or while one power source is switched for another, there may arise a concern that a power loss may be incurred by any one of the control modules.

Another technical challenge dealt with by the disclosed subject matter is to account for various states of the system in terms of which of the multiple power sources being connected thereto at a given point in time. Optionally, the multiple power sources may all be connected to the system, a single power source may be connected, or any number of them. While more than one power source is connected, leakage current between the power sources may be required to be limited to a minimum and/or even eliminated completely, as to not cause any damage to the power sources.

Pre-existing tools and/or techniques using power source selection and/or providing high power load suffer from many disadvantages, shortcomings, and/or limitations and are thus inadequate for dealing with the technical challenges at hand.

One exemplary pre-existing approach for power source selection is employed in mobile computing devices such as laptop and/or tablet computers, where two separate power sources, e.g., a primary power source driven by external current from a mains power line and/or the like and a secondary power source such as a rechargeable battery, may be controlled and utilized interchangeably. However, as each of these power source typically uses less than 100 W, any power losses on the switches are practically negligible and therefore a solution for current leakage between the power sources that relies on simple electrical separation by diodes and/or the like is acceptable. It will be appreciated however that the losses on diodes increase dramatically as the power increases. Moreover, as there is no high load in existence that may draw all and/or most of the energy in the system during power source selection, there is no requirement to mitigate any potential power loss to a control module in the interim, such as by providing a high energy reservoir and/or the like.

Another exemplary pre-existing approach for power source selection and/or high power load provision is employed in uninterruptible power supply or uninterruptible power source (UPS), which is an electrical apparatus that may provide emergency and/or backup power to a load when an input power source thereof and/or the mains power fails. However, UPS devices are normally very large and heavy and therefore can use power relays in order to mitigate any leakage and/or losses. Furthermore, UPS devices are not required to be single fault safe.

Yet another exemplary pre-existing approach for high power load provision is found in the context of high power medical laser devices. Such devices while including both a power source connectable to a mains power line outlet and/or the like and a rechargeable battery, do not however require switching between the two power sources in the middle of the operation. Therefore, the battery is the only power source for operation and the mains is used just for charging (i.e., a lower power application).

The disclosed subject matter provides for power source selection with high power load, which overcomes the drawbacks of pre-existing approaches and has further improvements thereupon.

In some embodiments, in order to select one of multiple power sources for providing power to a high load, each power source may be connected to the load through a switch. A suitable controller and/or control module may sense the presence of each power source and activate the switch of the desired power source while deactivating all the others. The switch may comprise at least one pair of transistors, preferably field-effect transistors (FETs) and more preferably N-channel FETs, connected in a common source configuration, and used as a High-Side-Switch (i.e., placed between the power source's positive lead and the high load, and not between the load and power source's negative lead). Such switch may be connected to each of the potentially available power sources, i.e., the power sources that are and/or intended to be connected to the high load channel and to supply power thereto.

In some embodiments, an energy reservoir and/or the like may be used to provide power to the high load and/or control module(s) during a transition between power sources in order the to support continuous operation thereof. The energy reservoir may be rechargeable, and may further be provided with a corresponding charging circuitry. The charging circuitry may use power from a power source connected to an external energy supply, such as a mains power line and/or the like.

In some embodiments, the one or more control modules may be separated from the high load channel electrically, such as for example by placing diodes and/or the like between each power source and the control module(s) in such a way that no current can be conducted from the control module to the high load.

Optionally, the energy reservoir and/or likewise component used for providing power during a transition between power sources, may be required to provide power only to the control module(s), e.g., due to separation thereof from each of the multiple power sources, as discussed herein. The power required by the control module(s) may be therefore much smaller than the power required by the high load, such as for example, smaller by a square multiplication value of a ratio between a power consumption of the high load and of the control module(s).

Optionally, all power sources may be connected to a common ground (e.g., a negative potential may be connected between all power sources), in order to enable operation of at least one control module (e.g., a single, central hardware and/or software control module) regardless of which power source being selected.

Optionally, the at least one pair of transistors utilized in a respective switch through which one of the power sources may be connected to and/or disconnected from the high power load, may be driven by the control module(s) via a charge pump and/or any likewise voltage conversion technology, such as for example a DC-to-DC converter and/or the like. Additionally or alternatively, another energy source with higher voltage (i.e., relative to a voltage of a respective one of the power sources connected via the switch and/or the like) may be utilized for driving the pair of FETs.

Optionally, the at least one pair of transistors in at least one of the plurality of switching circuitries may comprise and/or be a pair of metal-oxide-semiconductor field-effect transistors (MOSFETs) and/or the like. Additionally or alternatively, other suitable FETs may be employed.

In some embodiments, the pair of transistors may be serially connected and/or oppositely disposed relative to one another.

In some embodiments, the at least one pair of transistors in at least one of the plurality of switching circuitries may comprise and/or be a pair of N-channel FETs (N-FETs). Additionally or alternatively, the at least one pair of transistors (e.g., FETs and/or MOSFETs etc.) may comprise and/or be P-channel FETs (P-FETs). It will be appreciated that in a case where P-FETs are used as switches for the power sources, a need of using voltage converters such as charge pumps and/or the like for driving the FETs may be eliminated, however, such approach may result in reduced energetic efficiency and/or involve higher cost in manufacturing and/or operation, as compared to a respective switching circuitry using N-FETs, such as described herein.

Optionally, the multiple power source may comprise direct current (DC) power sources, alternate current (AC) power sources, and/or any likewise power sources and/or combinations thereof.

Optionally, one or more of the power sources may be rechargeable, and one or more charging circuitries may be provided for charging any one of the rechargeable power sources, such as by using power from one or more of power sources connected to external power supply such as a mains power line and/or the like.

One technical effect of utilizing the disclosed subject matter is to provide for energy efficient high load power source selection control. By using transistors (e.g., FETs) in the switching circuitry, energy consumption may be conserved and/or reduced, as less quiescent power consumption may be required and/or used.

Another technical effect of utilizing the disclosed subject matter is to provide for lower ON-resistance, as achieved by usage of transistors such as FETs and/or the like in the switching circuitry, thus giving more power to the load in turn.

Yet another technical effect of utilizing the disclosed subject matter is to eliminate usage of any moving parts and/or elements containing thereof, thereby reducing mean time between failures (MTBF), i.e., predicted elapsed time between inherent failures of any mechanical and/or electrical system components.

Yet another technical effect of utilizing the disclosed subject matter is that no cooling is required for the transistors (e.g., FETs) and/or the switching circuitry incorporating thereof, due to the energetic efficiency thereof as discussed herein.

It will be appreciated by a person skilled in the art that using the common source configuration for the pair of transistors (e.g., FETs) as discussed herein prevents current from being conducted back into a power source from other power sources and achieves the purpose of protecting each power source from leakage currents which may damage it.

It will further be appreciated by a person skilled in the art that using charge pumps and/or any likewise voltage conversion technology and/or another energy source with higher voltage and/or the like for driving the transistors where applicable (e.g., N-Channel FETs and/or the like) by the control module(s) enables operation thereof as high side switches (as FETs, particularly N-Channel FETs and/or the like, may be typically designed to be used as Low-Side-Switches), without compromising their superior efficiency and lower ON-resistance.

It will yet further be appreciated by a person skilled in the art that due to the separation of the control module(s) from the high power according to some embodiments of the disclosed subject matter, using a High-Side-Switch may be thus made mandatory.

Other and/or additional technical challenges, approaches, and/or effects may be apparent to a person skilled in the art in view of the present disclosure.

One practical application in which the disclosed subject matter may be useful and/or advantageous is quick heating of fluids, optionally taking place in field conditions, where no power supply from a mains power line may be available. For example, when performing a blood transfusion and/or other intravenous (IV) therapy administration, it may be desired to warm the blood and/or fluid administered to a body temperature, and to do so as fast as possible. Such task may thus require high energy load, on the one hand; yet, a heating device fulfilling such purpose may be required to be light weighted and robust as much as possible, in order to afford portability and usability thereof, on the other hand. By utilizing the disclosed subject matter, the aforesaid requirements may thus be accomplished in a cost effective manner.

Before explaining at least one embodiment in detail, it is to be understood that embodiments are not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. Implementations described herein are capable of other embodiments or of being practiced or carried out in various ways.

Reference is now made toFIG.1which is a schematic block diagram of an exemplary architecture of a system100for power source selection control, according to some embodiments. Reference is also made toFIGS.2-4which are schematic block diagrams of exemplary power feed unit101, controller102, and power consuming unit103of a system100for power source selection control, according to some embodiments. Reference is also made toFIG.5which is a flowchart schematically representing an optional flow of operations for power source selection control, according to some embodiments. One or more operations of the optional flow described with reference toFIG.5may be implemented by the system100for power source selection control described with reference toFIG.1, e.g., by the controller102described with reference toFIG.3utilizing the power feed unit101described with reference toFIG.2and power consuming unit103described with reference toFIG.4.

As shown inFIG.1, a power source selection control system such as100may comprise a power feed unit such as101, a controller such as102, and a power consuming unit such as103. The power feed unit101may comprise a plurality of power sources, such as110and113, which may optionally be heterogeneous power sources, as described herein. The plurality of power sources110,113may comprise, for example, direct current (DC) power sources, alternate current (AC) power sources, AC/DC power sources, and/or the like, as well as any combinations thereof. Additionally or alternatively, the plurality of power sources may comprise one or more rechargeable power sources, one or more non-rechargeable power sources, and/or combinations thereof. In some embodiments, one or more of the multiple power sources of power feed unit101may optionally be connectable to an external power supply, such as a mains power line, a power generator, and/or the like. Additionally or alternatively, the plurality of power sources may comprise one or more batteries. As a non-limiting example, power feed unit101may comprise a power supply such as110adapted to be connected to a mains power line, and a battery such as113, which may optionally be a rechargeable battery. The power supply110may optionally be a DC power supply.

In some embodiments, the power feed unit101may comprise an energy reservoir such as114that may be adapted to provide stable power supply input to the controller102, regardless of which one or more from power source(s)110,113of power feed unit101being operated and/or switched on/off at the time, as may be performed at502. The energy reservoir114may provide for load balancing and/or stabilizing the power supply to the controller102through interruptions and/or switches of power source(s)110,113.

The controller102may comprise and/or be implemented as one or more microcontroller(s) (MCU), microprocessor(s), state machine(s), field programmable gate array(s) (FPGA), digital signal processor(s) (DSP), application specific integrated circuit(s) (ASIC), and/or the like. The controller102may comprise a memory (not shown) in which code instructions executable by controller102may be stored, such as for example a random access memory (RAM), read-only memory (ROM), and/or the like. The memory may store code instructions that implement one or more acts of the optional flow of operations for power source selection control described with reference toFIG.5herein. Additionally or alternatively, one or more acts of the optional flow of operations ofFIG.5may be implemented in hardware.

The controller102may be connected to and/or in communication with each of the plurality of power sources110,113of the power feed unit101. For example, as shown onFIG.1and further onFIGS.2-3at greater detail, a positive lead of each of the power sources110,113may be provided as input to the controller102, to allow, for example, to the controller102to sense presence and/or availability of each of the power sources110,113, as may be performed at506.

The power feed unit101may be adapted to provide a current flow to a high power load such as135of the power consuming unit103, drawn from at least one of the plurality of power sources110,113. The high power load135may be required for and/or in course of performing a high power function of the power consuming unit103, such as for example, heating at a high rate and/or temperature, and/or the like. Each of the plurality of power sources110,113may be connected to and/or disconnected from high power load135via a respective one of a plurality of switching circuitries of the power consuming unit103, such as130and133, connected to and controlled by the controller102. In some embodiments, the controller may be connected to the high power load135and/or a channel thereof, in order, for example, to provide a pulse width modulation (PWM) signal for current control and/or the like.

As shown inFIG.2, the power feed unit101may further comprise a charging module such as112, which may be adapted for recharging one or more rechargeable power sources of power feed unit101such as battery113and/or the like, as may be performed at526. The charging module112may use, in operation and/or performing the charging function thereof, one or more of non-rechargeable power sources of power feed unit101such as power supply110and/or the like. The charging module112may provide and/or use alternate current (AC) to charge battery113. Optionally, the charging module112may charge and/or recharge the energy reservoir114, whether directly and/or via battery113, as may be further performed at526and/or otherwise. The energy reservoir114may receive, at an unstable input, a current flow from battery113and/or from power supply110via charging module112. The energy reservoir114may provide, in turn, a stable input to the controller102of a current flow having a proper load balance. The plurality of power sources of power feed unit101such as power supply110and battery113, and optionally the energy reservoir114as well, may be connected to a common ground, such as for example at a negative lead of each power source and/or the like. In order to prevent current leakage between the power sources110,113and/or to separate the controller102from the high load channel, there may be placed one or more unilateral and/or asymmetrical current conductance elements, such as diodes and/or the like, at appropriate locations, e.g., in precedence of an input to battery113and/or energy reservoir114supplying power to the controller102. For example, as illustrated onFIG.2, a diode may be placed along an input from charging module112to battery113. Similarly, a (further) diode may be placed at an input from battery113to energy reservoir114.

As shown inFIG.3, the controller102may be connected to the energy reservoir114as described with reference toFIGS.1-2for receiving therefrom a current flow of stable input power supply. The controller102may be connected to each of the plurality of power sources of power feed unit101such as power supply110and battery113, in order to be able to detect presence thereof and accordingly to select, based on the detection, one of the power sources to be used for operating the power consuming unit103, as may be performed at510. The controller102may be connected to each of the plurality of switching circuitries130,133of power consuming unit103corresponding to the plurality of power sources110,113of power feed unit101, for controlling activation of a selected power source, as may be performed at514, and/or for controlling deactivation of other power source(s), as may be performed at518. The controller102may control activation and/or deactivation of power source(s) using, for example, a charge pump drive at a respective one of switching circuitries130,133and/or the like. Optionally the controller102may be connected to the high power load channel to provide, for example, a power width modulation (PWM) signal and/or the like, as may be performed at522. The controller102may optionally be connected to a same common ground as of the power sources110,113and energy reservoir114.

As shown inFIG.4, each of the switching circuitries130,133of power consuming unit103may comprise a pair of N-Channel field-effect transistors (FETs), connected in a common source configuration, and positioned between a positive lead of a respective one of the plurality of power sources110,113and the high power load135. In some embodiments, the pair of N-channel field-effect transistors may be serially connected and/or oppositely disposed relative to one another. The pair of N-Channel FETs may be driven by voltage converters (e.g., charge pumps) such as N-FET drivers310and313. The N-FET drivers (e.g., charge pumps)310,313may be connected to and controlled by the controller102via respective high power switch control channels. The high power load135may be connected to and controlled by the controller102, e.g. using PWM signals and/or the like, via a respective control channel. The high power load135may optionally be connected to a same common ground as of the power sources110,113, energy reservoir114, and/or the controller102. Optionally the high power load135may be connected to the control channel and/or the common ground via an (additional) N-Channel FET, such as illustrated onFIG.4.

It is expected that during the life of a patent maturing from this application many relevant tools and/or techniques of power supply and/or electric energy stores will be developed and the scope of the terms “power source” and “battery” is intended to include all such new technologies a priori.

As used herein the term “about” refers to +10%.