Battery pack charger with a hybrid flyback converter

Abstract

A battery pack charger with a housing that includes a battery pack interface for the removable insertion of a battery pack and a power input. The battery pack charger includes a hybrid flyback converter with a primary side comprising a DC-DC half-bridge and a secondary side comprising a synchronous rectifier. The hybrid flyback converter is electrically connected between the power input and the battery pack interface and is configured to supply charging power from the power input to the battery pack interface.

Description

Related Applications

[0001] This application claims priority over preliminary US patent application No. 63 / 717,541, filed on November 7, 2024, the entire contents of which are hereby incorporated by reference. Area

[0002] The present disclosure relates to a converter arrangement and in particular a hybrid flyback converter for a battery pack charger. Summary

[0003] Certain power tools are operated using battery packs as their primary power source. The type of battery pack used depends on the power requirements of the specific power tool. Using a single charger that is compatible with multiple battery types offers advantages in terms of space saving, cost savings, and convenience. To enable faster charging of different battery types, the system may need to deliver a higher overall current. However, a higher charging current can lead to increased temperatures. Fans can be used to regulate the temperature of both the charger's electronic components and the battery packs.

[0004] In some aspects, the techniques described herein relate to a battery pack charger comprising: an enclosure; a power input; a battery pack interface provided on the enclosure and configured to accept a removable battery pack; a hybrid flyback converter (HFC) comprising a primary side including a DC-DC half-bridge and a secondary side including a synchronous rectifier, electrically connected between the power input and the battery pack interface, the HFC being configured to supply charging power from the power input to the battery pack interface; and a controller electrically connected to the HFC and configured to control the amount of power supplied on the secondary side.

[0005] In some aspects, the techniques described herein relate to a battery pack charger, comprising: an enclosure with a battery pack interface configured to accept a removable battery pack; a power input; a power circuit electrically connected between the power input and the battery pack interface and configured to supply charging power from the power input to the battery pack interface; a fan provided within the enclosure and near the battery pack interface; an alternating current (AC) sensor electrically connected between the power input and an input of the power circuit, the AC sensor being configured to measure an alternating current; and a fan control circuit electrically connected to the AC sensor and the fan, the fan control circuit being configured to control the fan based on the alternating current.

[0006] In some aspects, the techniques described here relate to a method for controlling a fan for a battery pack charger, the method comprising: measuring an RMS value of the alternating current with an AC current sensor electrically connected between a power input of the battery pack charger and a battery pack interface of the battery pack charger, the battery pack interface being configured to accept a removable battery pack; activating the fan when the RMS value of the alternating current exceeds a first threshold; and deactivating the fan when the RMS value of the alternating current subsequently falls below a second threshold. Brief description of the drawings Fig. Figure 1 shows an example of a battery pack charger according to some aspects of the present disclosure. Fig. Figure 2 shows an example of a battery pack of the first type, which is inserted into the exemplary battery pack charger of the Fig. 1 can be received according to some aspects of the present revelation. Fig. Figure 3 shows an example of a second type of battery pack that fits into the exemplary battery pack charger of the Fig. 1 can be received according to some aspects of the present revelation. Fig. Figure 4 shows a block diagram of an example configuration of a battery pack charger according to some aspects of the present disclosure. Fig. Figure 5 shows a main power circuit board arrangement with a converter arrangement according to some aspects of the present disclosure. Fig. Figure 6 shows a block diagram for the converter arrangement of the Fig. 5 according to some aspects of the present revelation. Fig. Figure 7 shows a diagram of an example of a DC-DC half-bridge used in the converter arrangement of the Fig. 6 is used according to some aspects of the present revelation. Fig. Figure 8 shows a block diagram of a low-current auxiliary busbar from the converter arrangement of the Fig. 6 according to some aspects of the present revelation. Fig. Figure 9 shows a block diagram of an example configuration of a battery pack charger with a fan according to some aspects of the present disclosure. Fig. Figure 10 shows a flowchart for a procedure for controlling the fan of the Fig. 5 according to some aspects of the present revelation. Fig. Figure 11 shows a first group configuration for the battery pack charger of the Fig. 1 according to some aspects of the present revelation. Fig. Figure 12 shows a second group configuration for the battery pack charger of the Fig. 1 according to some aspects of the present revelation. Fig. Figure 13 shows a flowchart of a procedure for controlling a fan for the battery pack charger of the Fig. 1 according to some aspects of the present revelation.

[0007] Before any examples of the disclosure are explained in detail, it should be understood that the disclosure, in its application, is not limited to the design details and arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of having other embodiments and of being practiced or carried out in various ways. It should also be understood that the language and terminology used herein serve for descriptive purposes and should not be considered restrictive.

[0008] The use of "including," "comprehensive," or "incorporating" and variations thereof shall encompass the elements listed thereafter and their equivalents, as well as additional elements. Unless otherwise specified or limited, the terms "mounted," "connected," "held," and "coupled," and variations thereof, shall be interpreted broadly to include both direct and indirect mounting, connections, mounting fixtures, and couplings.

[0009] Unless the context clearly indicates otherwise, the articles "ein," "eine," and "der / die / das" are not to be understood as "only" or "just one." Rather, these articles are to be understood as "at least one" or "one or more." Likewise, the terms "der / die / das" in relation to a noun previously introduced by the indefinite article "ein / eine" or "der / die / das" mean "at least one" or "one or more," unless the usage clearly indicates otherwise.

[0010] Furthermore, it should be understood that embodiments may include hardware, software, and electronic components or modules, which, for discussion purposes, may be presented and described as if the majority of the components were implemented exclusively in hardware. However, a person skilled in the art will recognize upon reading this detailed description that in at least one embodiment, the electronically based aspects may be implemented in software (e.g., stored on a non-volatile, computer-readable medium) executable by one or more processing units such as a microprocessor and / or application-specific integrated circuits (“ASICs”). It should therefore be noted that a variety of hardware- and software-based devices, as well as a variety of different structural components, may be used to implement the embodiments.For example, the “servers” and “computer equipment” described in the description may include one or more processing units, one or more computer-readable media modules, one or more input / output interfaces, and various connections (e.g., a system bus) that connect the components.

[0011] Relative terms such as "about," "approximately," "essentially," etc., used in connection with a quantity or condition, are understood by a person skilled in the art to include the stated value and to have the meaning given by the context (e.g., the term includes at least the degree of error associated with the measurement accuracy, the tolerances [e.g., manufacturing, assembly, use, etc.] associated with the respective value, etc.). Such terms should also be considered as a disclosure of the range defined by the absolute values ​​of the two endpoints. For example, the expression "from about 2 to about 4" also discloses the range "from 2 to 4." Relative terminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10%) of a stated value.

[0012] It is understood that, although certain drawings may illustrate hardware and software in specific devices, these representations are for illustrative purposes only. Functionalities described here as being executed by a single component may be distributed across multiple components. Likewise, functionalities executed by multiple components may be consolidated and executed by a single component. In some examples, the components shown may be combined or separated into separate software, firmware, and / or hardware. For instance, logic and processing may not reside in and be executed by a single electronic processor, but may be distributed across multiple electronic processors.Regardless of how they are combined or distributed, hardware and software components may reside on the same computer device or be distributed across different computer devices connected by one or more networks or other suitable communication links. Likewise, a component described as performing a particular function may also perform additional functions not described here. For example, a device or structure that is “configured” in a certain way is at least configured to do so, but may also be configured in a way not explicitly stated.

[0013] Accordingly, if the claims claim a device, method or system which includes, for example, a controller, control unit, electronic processor, computing device, logic element, module, memory module, communication channel or network or other element configured in a certain way, for example to perform several functions, the claim or claim element shall be understood as one or more of these elements, wherein any one of the one or more elements is configured as claimed, for example to perform one or more of the aforementioned functions, such that the elements as a group perform the functions together.

[0014] Further aspects of the examples become clear through consideration of the detailed description and the accompanying drawings. Detailed description

[0015] The Fig. Figure 1 shows an example of a battery pack charger 100 with a housing 105 and a plurality of battery pack interfaces 110 (e.g., one or more battery pack interfaces or receptacles). Each of the plurality of battery pack interfaces 110 is configured to receive a battery pack 120 and includes charger connection terminals that correspond to the battery connection terminals of the battery pack 120 (e.g., battery pack connection terminal 230, Fig. 2, Battery pack connection terminal 320, Fig. 3).

[0016] The battery pack charger 100 can be configured to charge different types of battery packs 120 (e.g., a battery pack 120a of the first type, a battery pack 120b of the second type). While two types of battery packs 120 are shown, a single type of battery pack 120 or any number of types of battery packs 120 are also conceivable.

[0017] The housing 105 comprises a center console 125 and two sockets 130 extending perpendicular to the center console 125 and at opposite ends thereof. The two sockets 130 may have openings 135 that form handles for transporting the battery pack charger 100. The center console 125 may include eight type 1 battery pack interfaces 110a on two sides of the center console 125, four on each side, and two type 2 battery pack interfaces 110b on one top surface of the center console 125. The type 1 battery pack interfaces 110a are configured to accept type 1 battery packs 120a in a removable (e.g., sliding) manner. The type 2 battery pack interfaces 110b are configured to accept type 20b battery packs 120b in a removable (e.g., pluggable) manner.

[0018] In one example, the first-type battery pack 120a is an 18 V battery pack, and the second-type battery pack 120b is a 12 V battery pack. The first-type battery pack 120a and the second-type battery pack 120b may additionally or alternatively have a different geometry (e.g., a sliding geometry, a tower geometry, etc.). The battery pack charger 100 may also include one or more ventilation openings and a corresponding fan 160 located inside the housing 105 to provide air circulation. The fan 160 may be configured to cool the electronics inside the housing 105 and / or the battery packs 120. The battery pack charger 100 may be designed for connection to a power source ( Fig. 4) via a power input ( Fig. 4) be configured. The battery pack charger 100 can have a total power output of approximately 760 watts (760 W) and a maximum total charging current of approximately 36 amperes (36 A).

[0019] The various types of 120V battery packs can include high-performance battery packs (e.g., with a capacity of 12 amp-hours (Ah) or more). These packs can be, for example, lithium-ion battery packs for power tools with a nominal voltage of approximately 18 volts. Other battery pack types may have a nominal voltage of approximately 36 volts, 48 ​​volts, 72 volts, or similar. Furthermore, the various types of 120V battery packs can include 12-volt power tool battery packs with three (3) lithium-ion battery cells, or fewer or more. Additionally or alternatively, the battery cells may contain chemicals other than lithium-ion, such as nickel-cadmium, nickel-metal hydride, or similar materials.

[0020] Each 120a, 120b battery pack can be connected to and used to power various motorized power tools (e.g., a cut-off saw, a miter saw, a table saw, a core drill, an auger, a crusher, a demolition hammer, a compaction machine, a vibrator, a compressor, a drain cleaner, a welding machine, a cable puller, a pump, etc.), outdoor tools (e.g., a chainsaw, a string trimmer, a hedge trimmer, a leaf blower, a lawnmower, etc.), other motorized equipment (e.g., vehicles, utility vehicles, a material handling cart, etc.), and non-motorized electrical equipment (e.g., a power supply, a lamp, an AC / DC adapter, a generator, etc.).

[0021] A user interface 140 can be arranged on the housing 105 to interact with and control the battery pack charger 100. The user interface 140 can include, among other things, user inputs 145 through which a user can interact with the battery pack charger 100. For example, a user can connect multiple battery packs 120 to the battery pack charger 100 and then define a sequence specifying the order in which and / or which battery packs 120 should be charged first.

[0022] The Fig. Figure 2 shows an example of a battery pack of the first type, which is used in the exemplary battery pack charger of the Fig. 1 according to some aspects of the present disclosure. The battery pack 120a of the first type can have a connecting section 210 with two parallel, spaced-apart rails 220 such that the battery pack 120a of the first type is a sliding battery pack that can be slidably engaged with the battery pack interface 110a of the first type. The connecting section 210 also includes battery terminals 230 for electrically connecting the battery pack 120a of the first type to the charging terminals of the battery pack charger 100 or to another device, for example, a power tool. In one example, the battery pack 120a of the first type is an 18 V lithium-based battery pack.

[0023] The Fig. Figure 2 shows a second-type battery pack 120b, which, according to an example, can be inserted into the second-type battery pack interface 110b. The second-type battery pack 120b can have a tower-like connecting section 310, which can be at least partially inserted into the second-type battery pack interface 110b. The connecting section 310 also includes battery terminals 320 for electrically connecting the second-type battery pack 120b to the charging terminals of the battery pack charger 100 or to another device, such as a power tool. In one example, the second-type battery pack 120b is a 12V lithium-based battery pack.

[0024] The first-type 120a battery pack and the second-type 120b battery pack are described as being inserted and / or mounted into the 100 battery pack charger. While slide-in and mountable interfaces are shown, any type of interface capable of electrically connecting the different types of 120 battery packs to the 100 battery pack charger is conceivable, including snap-in, rotation, or similar mechanisms.

[0025] The Fig. Figure 4 is a block diagram showing a configuration of a battery pack charger 400, e.g., the battery pack charger 100. Fig. 1, illustrated by an example. In the example shown, the battery pack charger 400 comprises a power input 410, a power circuit 415, a controller 420, and one or more sensors 425. The one or more sensors 425 include, for example, a current sensor, a voltage sensor, or the like.

[0026] The power input 410 can, for example, be connected to a mains cable that can be plugged into a wall socket to draw power from a mains supply or from a power source (e.g., an external AC power source 430). The power input 410 can also include an interface for connection to a solar panel or other power source. The power input 410 is electrically connected to the power circuit 415, which is electrically connected to a battery pack interface 435. Although a single battery pack interface 435 is shown, the battery pack charger 400, as mentioned above, can include multiple battery pack interfaces 435.

[0027] In one example, the power circuit 415 includes an AC-DC converter (e.g., a rectifier) ​​to convert alternating current from the power input 410 to direct current and supply the battery pack 120 with direct current when connected to the battery pack interface 435. The power circuit 415 includes a converter assembly 440 to convert the input power into a suitable power stage (e.g., a requested power stage different from the input power stage) for charging a battery pack (e.g., the battery pack 120). The converter assembly 440 can include the AC-DC converter, or the AC-DC converter can be integrated into the power input 410. The converter assembly 440 can be controlled by the controller 420 to change the amount of current or power provided at the secondary side (i.e., the output side) of the converter assembly 440.

[0028] The controller 420 comprises combinations of hardware and software that, among other things, serve to control the operation of the battery pack charger 400. For example, the controller 420 includes, among other things, a processing unit 450 (e.g., a microprocessor, a microcontroller, an electronic processor, an electronic controller, or another suitable programmable device), a memory 455, input units 460, and output units 465. The processing unit 450 includes, among other things, a control unit 470, an arithmetic logic unit (“ALU”) 475, and a plurality of registers 480 (in the Fig. 4 (represented as a group of registers) and is implemented using a known computer architecture (e.g., a modified Harvard architecture, a von Neumann architecture, etc.). The processing unit 450, the memory 455, the input units 460, and the output units 465, as well as the various modules or circuits connected to the controller 420, are connected by one or more control and / or data buses (e.g., the common bus 485). The controller 420 can communicate with a battery pack controller of the battery pack 120 via a communication line 490. The control and / or data buses are in the Fig. 4 generally shown for illustrative purposes. Although the control 420 in the Fig. While the controller 420 is represented as a single controller, it could also comprise multiple controllers configured to work together to achieve a desired level of control for the battery pack charger 400. Therefore, all control functions and processes described herein with respect to the controller 420 could also be performed by two or more controllers operating in a decentralized manner. For example, the battery pack charger 400 could include a controller for communicating with the battery packs 120 and separate controllers (e.g., converter controllers) for controlling one or more converters within the power circuit 415.

[0029] The Memory 455 is a non-volatile, computer-readable medium and comprises, for example, a program memory area and a data memory area. The program memory area and the data memory area can include combinations of different memory types, such as read-only memory (“ROM”), random-access memory (“RAM”) (e.g., dynamic RAM [“DRAM”], synchronous DRAM [“SDRAM”], etc.), electrically erasable programmable read-only memory (“EEPROM”), flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, or electronic storage devices. The Processing Unit 450 is connected to the Memory 455 and configured to execute software instructions capable of being written to a RAM of the Memory 455 (e.g., during execution), to a ROM of the Memory 455 (e.g., during execution), or to a ROM of the Memory 455 (e.g., during execution).on a generally permanent basis) or on another non-volatile, computer-readable medium, such as another memory or a floppy disk. The software included in the implementation of the battery pack charger 400 and the controller 420 can be stored in the memory 455 of the controller 420. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The controller 420 is configured, among other things, to retrieve and execute instructions from memory 455 related to the control processes and procedures described herein. In other examples, the controller 420 includes additional, fewer, or different components.

[0030] The battery pack charger 400 includes additional components that have been omitted from the illustrations and this description for the sake of simplicity. For example, the battery pack charger 400 may include outputs to supply external devices with power from the battery pack(s) 120. Additionally, the battery pack charger 400 may include various FETs and a gate driver for controlling the FETs. For example, a charging FET may be connected between the power circuit 415 and the battery pack interface 435.

[0031] The Fig. Figure 5 is a block diagram of the power circuit 415 according to an example. The power circuit 415 can be electrically connected between the power source 430 and the battery pack interface 435. The power circuit 415 is electrically coupled to a charger controller 560 (e.g., a main controller of the battery pack charger 400). In the example shown, the power circuit 415 includes an electromagnetic interference (EMI) filter 515, an input rectifier 520, the converter assembly 440, and a constant current / constant voltage (CC / CV) control module 525. The CC / CV control module 525 enables fast charging without the risk of overcharging the battery pack 120. The battery pack 120 is initially charged with a constant current until it reaches a certain voltage, and then charging continues at this voltage while the current decreases. The power circuit 415 may include more or fewer components than revealed herein.

[0032] The power circuit 415 comprises a main power path 530 and a control path 535. The main power path 530 supplies the battery pack interface 435 with operating power (e.g., charging power) from the power source 430. The control path 535 is used to exchange control and / or communication signals between the power circuit 415 (e.g., controllers and / or control components of the power circuit 415) and the charger controller 560. A fuse 540 and a negative temperature coefficient (NTC) thermistor 545 can be electrically connected between the power source 430 and the EMI filter 515. The fuse 540 and the NTC thermistor 545 protect the power circuit 415 and / or the converter assembly 440 from current surges, over-temperature conditions, or similar events.

[0033] The EMI filter 515 filters out electromagnetic interference from the alternating current received by the power source 430. The filtered alternating current from the EMI filter 515 is fed to the input rectifier 520. The input rectifier 520 converts the alternating current from the power source 430 into direct current. A detection circuit 550 is coupled to the output of the EMI filter 515 to detect the presence of the power source 430 on the main power path 530. The detection circuit 550 provides a detection signal to the converter arrangement 440 to indicate the presence of alternating current from the power source 430. The portion of the power circuit 415 from the power input to the output of the input rectifier 520 can form an AC-DC stage 546 of the power circuit 415. The charger control 560 can be the main control of the battery pack charger 100, 400 and controls the power supply to the battery pack connection(s).For example, the charger controller 560 can control the switches or relays connected between the power circuit 415 and the battery pack interface(s) 435 to activate and deactivate the charging of the battery pack(s) 120. The charger controller 560 can also provide additional protection (e.g., against overtemperature, overvoltage, overcurrent, etc.) for the battery pack charger 100, 400.

[0034] The Fig. Figure 6 shows a block diagram of the converter assembly 440 according to an example. The converter assembly 440 comprises a power factor correction (PFC) boost converter 600, a hybrid flyback converter (HFC) 605, a converter controller 610, a low-current auxiliary rail 615, and a synchronous rectifier controller 695. The PFC converter 600 receives direct current from the input rectifier 520 and boosts the voltage to, for example, 395 V, 400 V, or the like, relative to a voltage supplied by the power source 430 (e.g., 110 / 120 volts and 240 volts). In some examples, the PFC converter 600 may be omitted or replaced by a different type of DC-DC converter.

[0035] The HFC 605 comprises a primary side 625p and a secondary side 625s. The HFC 605 is electrically connected to the PFC converter 600 on the primary side 625p and to the controller 420 on the secondary side 625s. A galvanic isolation barrier 630 isolates high-voltage components (left, e.g., the primary side 625p) from low-voltage components (right, e.g., the secondary side 625s). The galvanic isolation barrier 630 can be provided by the HFC 605. An optocoupler arrangement 635 can be used to exchange control signals between the high-voltage and low-voltage components across the galvanic isolation barrier 630.

[0036] The HFC 605 incorporates the DC-DC half-bridge 640 on the primary side 625p. Fig. Figure 7 shows an example of a DC-DC half-bridge 640. The DC-DC half-bridge 640 comprises a plurality of switches 645 (e.g., a high-side switch 645H and a low-side switch 645L). The center point of the plurality of switches 645 is connected via an inductor 670 to one or more primary windings 660. A resonant capacitor 675 is electrically connected in series with the one or more primary windings 660 and the inductor 670.

[0037] Back to the Fig. The HFC 605 comprises a transformer 655 with one or more primary windings 660 and one or more corresponding secondary windings 665. The transformer 655 forms the galvanic isolation barrier 630 in the main power path 530, and the optocoupler arrangement 635 forms the galvanic isolation barrier 630 in the control path 535. The converter controller 610 is used to control the plurality of switches 645. The converter controller 610 can include control functions for the AC-DC stage 546 and the DC-DC stage 548 (e.g., DC-DC converter components between the output of the input rectifier 520 and the output of the HFC 605), which can be combined into a single chip.In other words, the 610 converter controller can combine a multimode AC-DC PFC controller and a multimode DC-DC hybrid flyback converter controller in a single package, thereby enabling a reduction in external components and increasing system performance by harmonizing the operation of the two stages.

[0038] The HFC 605 includes a synchronous rectifier 680 on the secondary side 625s. The synchronous rectifier 680 includes at least one switch 685. The at least one switch 685 can be implemented as a MOSFET, wideband gap FET, or the like. The synchronous rectifier controller 695 is electrically connected to the synchronous rectifier 680 to control the at least one switch 685. The synchronous rectifier controller 695 can use a driver that utilizes the flip-chip assembly technology for the HFC 605. The converter controller 610 controls the plurality of switches 645, and the synchronous rectifier controller 695 controls the switch 685 to convert the DC current between the AC-DC stage 546 and the battery pack interface 435. Fig. 4).

[0039] The constant current / constant voltage (CC / CV) control module 525 is electrically connected to the charger control 560, the optocoupler assembly 635, and the rectifier control 695. A current sensor 690 is provided on the secondary side 625s to detect the current supplied to the battery pack interface(s) 435. The CC / CV control module 525 can supply signals to the converter control 610 and the synchronous rectifier control 695 based on the current detected by the current sensor 690 and / or control signals received by the charger control 560.

[0040] The low-current auxiliary rail 615 is independent of the main power path 530. The low-current auxiliary rail 615 comprises a first control circuit 700 on the primary side 625p of the HFC 605 and a second control circuit 705 on the secondary side 625s of the HFC 605. The low-current auxiliary rail 615 is used to supply operating current at a lower power level (e.g., 15 volts, 5 volts, or similar) to the control components of the power circuit 415.

[0041] The advantages of integrating the 440 converter assembly with the HFC 605 include high efficiency over a wide input range. The 440 converter assembly can be used with power supplies ranging from 90 VAC to 265 VAC and for power ratings from 140 W to 300 W. The 440 converter assembly with the HFC 605 also offers high efficiency over a wide output range, making it suitable for battery pack chargers. The 655 transformer and the 675 resonant capacitor store energy during switching, resulting in a smaller transformer size and thus higher power density. The energy stored in the transformer's leakage inductance can be reused to further increase efficiency.By appropriately controlling the switches 645 and 685, the energy stored in the resonant capacitor 675 can be used to achieve a zero-voltage circuit (ZVS) across the plurality of switches 645 and a zero-current circuit (ZCS) across at least one switch 685. ZVS and ZCS also increase efficiency. In this respect, the converter arrangement 440 with the HFC 605 is capable of achieving an efficiency of 93% or more at full load.

[0042] The Fig. Figure 8 shows a block diagram of the low-current auxiliary rail 615, which is provided independently of the main power path 530. The low-current auxiliary rail 615 includes a first control circuit 700 on the primary side 625p of the HFC 605 and a second control circuit 705 on the secondary side 625s of the HFC 605. The low-current auxiliary rail 615 includes an auxiliary transformer 710 and provides an auxiliary power supply for all electrical components of a battery pack charger, e.g., the battery pack charger 100 ( Fig. 1) and / or the 400 battery pack charger ( Fig. 4), ready. The auxiliary current transformer 710 can include an additional winding to the one or multiple windings of the transformer 655. The first control circuit 700 includes a pair of primary windings 715, and the second control circuit includes a corresponding pair of secondary windings 720. The second control circuit 705 also includes two DC recovery circuits 725 and a linear regulator 730. Instead of using a rectifier, the DC recovery circuits 725 provide better cross-regulation. The switches 645 and 685 can be used to transfer power to the low-current auxiliary rail 615 when the main power path 530 is switched off. Stacking the DC recovery circuits 725 increases the output voltage at low load (<0.5 W). The output voltage can be increased from 5 V to 15 V. The 730 linear regulator protects downstream circuits from overvoltage.

[0043] In the Fig. Figure 9 shows an example of a battery pack charger 800. The battery pack charger 800 can have some or all of the features (not all are shown for simplicity) described in relation to the battery pack chargers 100 and 400, including three dedicated power circuits 415, each having a PFC / HFC configuration, which, in relation to the Fig. 6, and a control circuit comprising three battery pack interfaces 435 as previously described herein. The battery pack charger 800 includes a fan 805 (e.g., fan 160) located near the battery pack interfaces 110. A fan control circuit 810 is electrically connected to the fan 805. An AC current sensor 815 is electrically connected to the fan control circuit 810 to be used as feedback for controlling the fan 805. In one example, the AC current sensor 815 can be placed along the main power path 530 in electrical connection with the one described in the Fig. The fan control circuit 810 may be provided by the fuse 540 shown in Figure 5 and / or the NTC thermistor 545. When the AC current sensor 815 detects an input current exceeding a certain value, the fan control circuit 810 switches on the fan 805. The fan 805 can be designed for 24 volts (24 V). The power to operate the fan 805 can be obtained from an output 820 of one of the three power circuits 415 for controlling the power supplied to the battery packs 120 (12.5 V–21 V). The fan control circuit 810 may include a controller (e.g., controller 420) and a switch or relay electrically connected between the power circuit 415 and the fan 805. The controller can open and close the switch or relay based on the AC current measured by the AC current sensor 815 to control the fan 805.

[0044] The Fig. Figure 10 represents a state machine 900, illustrating the control of the fan 805. In a first state 905, the fan is disabled, either switched off or remaining off. In a second state 910, the fan is enabled or switched on. When the AC current sensor 815 detects a current (IRMS) associated with switching on the power to the battery pack charger 800, the fan 805 can remain in the first state 905. For example, when the sensing circuit 550 sends a sensing signal to the converter arrangement 440 to indicate the presence of AC current from the power source 430, the fan 805 is not switched on immediately. Rather, the fan remains in the first state 905 until the measured IRMS exceeds a first threshold, for example, 2 amperes RMS.In a second state (910), the fan is activated or switched on when the measured IRMS value reaches or exceeds the first threshold. The fan (805) returns to the first state (905) when the measured IRMS value subsequently falls below a second threshold, for example, 2 ARMS minus a hysteresis amount.

[0045] The Fig. Figure 11 shows a first charging configuration 1000 for a battery pack charger 100 (or a battery pack charger 400) according to one aspect of the present disclosure. In the first charging configuration 1000, the battery pack charger 100 is divided into several groups: a first group 1010 comprises a first variety of battery pack interfaces 110 (e.g., two battery pack interfaces 110a of the first type), a second group 1015 comprises a second variety of battery pack interfaces 110 (e.g., two battery pack interfaces 110a of the first type and one battery pack interface 110b of the second type), a third group 1020 comprises a first variety of battery pack interfaces 110 (e.g., two battery pack interfaces 110a of the first type), and a fourth group 1025 comprises a fourth variety of battery pack interfaces 110 (e.g., two battery pack interfaces 110a of the first type and one battery pack interface 110b of the second type).

[0046] In the example configuration, each group can only charge one battery pack 120 at a given time, in the order in which the battery packs 120 are inserted. However, multiple groups can charge a single battery pack 120 simultaneously. For example, if all battery pack interfaces 110 are populated with battery packs 120 before the AC power supply is switched on, the battery pack interfaces 110 are prioritized from right to left for the first and second groups 1010 and 1015, and from left to right for the third and fourth groups 1020 and 1025 (e.g., counterclockwise), as indicated by the arrows 1030. A different configuration or charging sequence can also be used to prioritize charging between the different battery packs 120 (e.g., according to user input via the user interface 140).

[0047] Furthermore, the first-type 120a battery packs are prioritized such that, in the previously described example, in the second and fourth groups 1015 and 1025, the first-type 120a battery packs are charged first and second, and the second-type 120b battery packs are charged third. In the illustrated example, the solid line 1035 represents a 120 battery pack being charged, and the dotted line 1040 represents a 120 battery pack waiting to be charged.

[0048] In another example, the first battery pack 120 to be used begins the charging process when the battery charger 100 is already plugged into the power source ( Fig. 1) and no batteries 120 are available. If, in this example, a battery pack 120b of the second type is inserted before a battery pack 120a of the first type, the battery pack 120b of the second type takes priority. In other words, regardless of the type of battery pack 120 inserted, the one inserted first immediately begins charging.

[0049] The Fig. Figure 12 shows a second charging configuration 1100 for the battery pack charger 100 according to one aspect of the present disclosure. In the second charging configuration 1100, a first group 1110 and a fourth group 1125 each comprise two battery pack interfaces 110a of the first type and one battery pack interface 110b of the second type, while a second group 1115 and a third group 1120 each comprise two battery pack interfaces 110a of the first type.

[0050] In the example configuration, each group can only charge one battery pack 120 at a given time, in the order in which the battery packs 120 are inserted. However, multiple groups can charge a single battery pack 120 simultaneously. For example, if all battery pack interfaces 110 are populated with battery packs 120 before the AC power supply is switched on, the battery pack interfaces 110 for all groups 1110, 1115, 1120, 1125 are prioritized from bottom to top, as indicated by arrow 1130. For the first and fourth groups 1110 and 1125, the battery packs 120a of the first type (e.g., at the bottom) can be charged first, the battery packs 120b of the second type can be charged second, and the remaining (e.g., upper) battery packs 120a of the first type can be charged last.In the example shown, the solid line 1135 represents a battery pack 120 that is being charged, and the dotted line 1140 represents a battery pack 120 that is waiting to be charged.

[0051] In another example, the first battery pack 120 to be used begins the charging process when the battery charger 100 is already plugged into the power source ( Fig. 1) and no batteries 120 are available. If, in this example, a battery pack 120b of the second type is inserted before a battery pack 120a of the first type, the battery pack 120b of the second type takes precedence.

[0052] A maximum charging current of 36 A can be distributed across the various 110 interfaces, including the first-type 110a battery pack interfaces and the second-type 110b battery pack interfaces. The 100 battery charger can distribute the maximum charging current of 36 A in different ways depending on the various combinations of battery types.

[0053] The first-type battery pack interface 110a is configured to supply the first-type battery pack 120a with a charging current of 21 V and 36 A (i.e., a maximum power of 760 watts). The second-type battery pack interface 110b is configured to supply a charging current of 12.6 V and 20 A (i.e., a maximum power of 252 watts). A maximum power of 700 W to 800 W (for example, 775 W or 792 W) at a maximum current of 36 A can be distributed among a maximum of four battery packs connected to the battery pack charger 100 in the example configuration shown. In other example configurations, a different number of battery packs with different maximum power and currents can be charged.

[0054] The Fig. Figure 13 shows a flowchart of a procedure 1200 for controlling the fan 805 for the battery pack charger 800. The procedure 1200 can be carried out by the controller 420 using the processing unit 450 according to the state machine 900 using the memory 455 for storage and the arithmetic-logical unit 475 to determine the next state 905, 910 based on input units 460 (see the Fig. 4 and Fig. 10).

[0055] In block 1210, procedure 1200 includes measuring the root mean square (RMS) value of the alternating current. For example, the RMS value of the current can be detected and measured using the AC current sensor 815, which is electrically connected to the fan control circuit 810 and is located within the battery pack charger 800. Monitoring and measuring the AC current for the battery pack charger 800 using the state machine 900 can be performed while the fan 805 is switched off. In one example, monitoring is carried out at a sampling rate between 10 Hz and 1 kHz. Real-time control of the AC current sensor 815 can be performed at a rate of 100 Hz, thus striking a balance between responsiveness and processing load.

[0056] In block 1220, procedure 1200 involves activating (switching on) the fan 805 when the RMS value of the AC current exceeds the first threshold. For example, when the RMS value of the AC current measured by the AC current sensor 815 exceeds 2 ARMS. More precisely, the AC current sensor 815 can be a Hall-effect sensor configured to output a voltage measurement based on the RMS value of the AC current. An analog-to-digital converter (ADC) reads the voltage, the control unit 470 converts the voltage into a current value and compares the current value to the first threshold. If the current value exceeds the first threshold, for example, 2 ARMS, the processing unit 450 outputs a signal to activate the fan 805. Although 2 ARMS is shown ( Fig. 10), other threshold values ​​are also conceivable.

[0057] In block 1230, procedure 1200 involves disabling (e.g., switching off) the fan 805 when the measured current value falls below the second threshold. For example, when the RMS value of the AC current measured by the AC current sensor 815 falls below 2 ARMS. The second threshold can be lower than the first threshold by an amount corresponding to the hysteresis. More precisely, the hysteresis can have a predetermined value of 0.5 ARMS, and when the current value falls below the second threshold, for example, 1.5 ARMS, the processing unit 450 outputs a signal to disable the fan 805. It is understood that the first and second thresholds can vary depending on the implementation and predefined values ​​based on the circuitry of the controller 420. For example, the first threshold can be 3 ARMS and the second threshold can be 2 ARMS, with a predetermined hysteresis of 1 ARMS.

[0058] Although the revelation has been presented in detail with reference to certain favored examples, variations and modifications exist within the scope and spirit of one or more independent aspects of the revelation, as described. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 717.541

[0001]

Claims

[1] A battery pack charger, comprising: a case; a power input; a battery pack interface that is provided on the housing and configured to accept a removable battery pack; a hybrid flyback converter (HFC) comprising a primary side including a DC-DC half-bridge and a secondary side including a synchronous rectifier, electrically connected between the power input and the battery pack interface, wherein the HFC is configured to supply charging power from the power input to the battery pack interface; and a controller that is electrically connected to the HFC and configured to control the amount of power supplied on the secondary side. [2] The battery pack charger according to claim 1, further comprising: an input rectifier which is electrically connected between the power input and the HFC, wherein the input rectifier is configured to convert alternating current from the power input to direct current, the direct current being supplied to the HFC. [3] The battery pack charger according to claim 2, wherein the HFC comprises a plurality of switches and wherein the controller is configured to control the plurality of switches to convert DC current between the power input and the battery pack interface. [4] The battery pack charger according to claim 3, further comprising a power factor correction boost converter (PFC) electrically connected between the input rectifier and the DC-DC half-bridge of the hybrid flyback converter. [5] The battery pack charger according to claim 4, wherein the controller comprises a single controller to control the PFC boost converter and the HFC converter provided on a single chip. [6] The battery pack charger according to claim 1, wherein the synchronous rectifier comprises at least one switch, wherein the at least one switch is a MOSFET. [7] The battery pack charger according to claim 1, further comprising a fan which is provided inside the housing and configured to cool the electronics inside the housing and / or the battery pack. [8] The battery pack charger according to claim 7, further comprising: an AC current sensor that is provided in a current path between the power input and the battery pack interface; and a fan control circuit that is electrically connected to the AC sensor and configured to control the fan based on the alternating current measured by the AC sensor. [9] The battery pack charger according to claim 1, wherein the battery pack interface is a battery pack interface of a first type configured to receive a battery pack of a first type, further comprising a battery pack interface of a second type provided on the housing and configured to receive a battery pack of a second type which is of a different type than the battery pack of the first type. [10] The battery pack charger according to claim 9, wherein the battery pack of the first type has a nominal voltage of 18 V and the battery pack of the second type has a nominal voltage of 12 V. [11] The battery pack charger according to claim 1, further comprising a plurality of battery pack interfaces on the housing, wherein the plurality of battery pack interfaces is divided into groups, each group comprising at least two battery pack interfaces. [12] The battery pack charger according to claim 11, wherein a first group comprises a plurality of battery pack interfaces of a first type and a second group comprises a plurality of battery pack interfaces of a first type and a battery pack interface of a second type. [13] The battery pack charger according to claim 12, wherein only one battery pack in each group is charged at the same time. [14] The battery pack charger according to claim 1, wherein the total power output of the battery pack charger is 760 watts. [15] A battery pack charger, comprising: a housing with a battery pack interface configured to accept a removable battery pack; a power input; a power circuit that is electrically connected between the power input and the battery pack interface and is configured to supply charging power from the power input to the battery pack interface; a fan that is located inside the housing and near the battery pack interface; an AC current sensor that is electrically connected between the power input and an input of the power circuit, wherein the AC current sensor is configured to measure an alternating current; and a fan control circuit that is electrically connected to the AC sensor and the fan, wherein the fan control circuit is configured to control the fan based on the AC current. [16] The battery pack charger according to claim 15, wherein the fan control circuit is configured to activate the fan when the alternating current exceeds a first threshold. [17] The battery pack charger according to claim 16, wherein the fan control circuit is configured to deactivate the fan when the alternating current falls below a first threshold and the fan is activated. [18] The battery pack charger according to claim 17, wherein the alternating current is measured as effective current (RMS), the first threshold is 2 ARMS and the second threshold is below the first threshold by a hysteresis amount. [19] A method for controlling a fan for a battery pack charger, the method comprising: Measuring an effective value of alternating current (RMS AC) with an AC current sensor electrically connected between a power input of the battery pack charger and a battery pack interface of the battery pack charger, the battery pack interface being configured to accept a removable battery pack; Activating the fan when the RMS AC current exceeds a first threshold; and deactivating the fan if the RMS value of the alternating current subsequently falls below a second threshold. [20] Method according to claim 19, wherein the second threshold is lower than the first threshold.

Images