Power supply system for battery operated tools

Abstract

A power supply system includes an external power supply that directly connects to a battery pack of a cordless power tool. Power is supplied to the power tool via a connection between the power supply and the battery pack. Since the power supply is connected directly to the battery pack, the power can be used to charge the battery of the battery pack when the tool is in the "off" state and provide power to the tool motor when the tool is in the on state to extend tool runtime. If the power tool is drawing less power than the power supply can provide, the difference in power is used to charge the battery, and if the tool is drawing more power than the power supply can provide, then the battery supplements the needed extra power.

Description

POWER SUPPLY SYSTEM FOR BATTERY OPERATED TOOLSBACKGROUND

[0001] Battery-operated cordless power tools are desirable for portability and maneuverability, but the battery pack of such power tools frequently provides a limited operating time or “run time.” This can be compared to corded power tools where the tool run times can be infinite as long as the power tool remains connected to the AC mains. Although some solutions in the market offer an adapter that converts AC to DC to fully power the cordless tool from the AC mains, these solutions may be bulky and relatively expensive. It is desired to have a power supply system for a battery-operated cordless power tool in which the overall size and weight are modest or low, and that provides an extended tool run time.SUMMARY

[0002] The power supply system described herein utilizes an external power supply to keep the overall size and weight down, but also extends the run time for battery-operated tools. In this system, an external power supply connects directly to a battery pack of a cordless power tool. The connection is made through a connector and power is provided to the power tool through this connector. With power connected directly to the battery pack, this power can be used to:1.) Charge the battery of the battery pack when the tool is in the “off’ state; and2.) Provide power to the motor when the tool is in the on state to extend tool runtime. i. If the tool is drawing less power than the power supply can provide, the difference in power would go towards charging the battery (charge while run); and ii. If the tool is drawing more power than the power supply can provide, then the battery will supplement the needed extra power.

[0003] The power supply and battery from the power supply system may also be used to directly power a low power secondary tool (for example, a glue pen). As used herein, the term “low power” refers to power requirements in a range of 10 watts to 60 watts. In some embodiments, the power supply may be directly connected to a secondary tool and may directly power thesecondary tool. The battery can also be used as a power bank to power the secondary tool through the charge input connector. The battery pack will include the necessary battery discharge management, which will keep the secondary tool as simple and low cost, especially with regards to electronics.

[0004] In some aspects, a multi-functional system for power tools is implemented in a battery pack consisting of at least one electrochemical cell. The system may include a power supply, a battery pack and a cordless power tool. Adaptations are provided in the battery pack, in the tool itself, or implemented across any combination thereof, such that the system allows the following modes of operation: battery discharge only, battery charge only, and charge-while-run / loadsharing operation. Information can be exchanged either directly or indirectly between these system sub- components to facilitate the operational modes.

[0005] In discharge mode, the battery pack can discharge through a primary interface / connector and / or a secondary interface / connector.

[0006] In charge-only mode, the battery pack discharge is off, and the battery pack is charging.

[0007] Charge- while-run / load-sharing mode works as follows: When the tool load current demand through the primary and / or secondary interface(s) can be provided by the power supply at a voltage higher than the battery pack voltage, the power supply provides current to the load and to the charging IC which charges the battery pack simultaneously. When the current demanded by the load is greater than the current limit of the power supply or causes the power supply voltage to drop below the battery pack voltage, the load current is provided by both the battery pack and the power supply simultaneously. This mode allows increased output power over using either of the sources acting alone.

[0008] Either the power supply output voltage will be exclusively greater than the desired charge voltage and the charging integrated circuit (IC) will be a buck converter, or the power supply can have a smaller, equal, and / or greater voltage than the cells and the charging IC will be a buckboost or SEPIC converter. The power supply can be connected to the load interface either directly, when providing an acceptable voltage for the tool to use, or through a DC-DC converter. This system can connect to the external DC power supply either through USB-C PD connection, a standard connector or through a proprietary connector.BRIEF DESCRIPTION OF THE FIGURES

[0009] Fig. 1 illustrates a first or cordless configuration of a power supply system in which a battery-operated power tool is supplied with power by a battery pack.

[0010] Fig. 2 illustrates a second configuration of a power supply system in which the battery-operated power tool is supplied with power by a battery pack that has a wired connection to a power supply and mains power.

[0011] Fig. 3 illustrates a third configuration of a power supply system in which a battery-free, low power tool is supplied with power by the power supply of Fig. 2 and mains power.

[0012] Fig. 4 illustrates a fourth configuration of a power supply system in which the battery-free, low power tool of Fig. 3 is supplied with power by the battery pack of Fig. 1.

[0013] Fig. 5 is a schematic diagram of a first embodiment of the battery pack of the power supply system.

[0014] Fig. 6 is a schematic diagram of a second embodiment of the battery pack of the power supply system.

[0015] Fig. 7 is a schematic diagram of a third embodiment of the battery pack of the power supply system.

[0016] Fig. 8 is a schematic diagram of a power tool having an integrated battery system.DESCRIPTION

[0017] Referring to Figs. 1 and 5, the power supply system 1 includes four configurations for supplying power to a power tool. The power supply system 1 may be used to supply power to a battery-operated cordless power tool 2, also referred to as the “primary tool” 2. In addition, the power supply system 1 may be used to supply power to a low-power power tool 3, also referred to as the “secondary tool” 50.

[0018] As seen in Fig. 1 , a first power supply configuration for supplying power to the battery-operated cordless power tool 2 is a cordless configuration and includes the cordless power tool 2 and a battery pack 12 that is directly connected to the power tool 2. In particular, a battery interface 4 of the power tool 2 electrically and mechanically engages the tool interface 16 (e.g., the power outlet connector 16) of the battery pack 12. In the first power supply configuration, the cordless power tool 2 may simply be used as a typical battery-operated tool.

[0019] The battery-operated cordless power tool 2 may be any power tool that can be connected with a standard battery pack (e.g., sanders, drills, rotary tools, etc.). The cordless power tool 2 may use more than 100W of power and includes battery discharge management (BDS) with the BDS electronics contained in the tool 2.

[0020] The battery pack 12 may include a battery 26, a charge management electronic control unit (CM ECU) 24, a discharge control device 22, and a micro control unit (microcontroller or MCU) 20 for control of battery pack components, and the power inlet and outlet connectors 14, 16. The power outlet connector 16 contains battery contact pins as well as battery pack signal information that is used by the primary tool 2. The battery pack also includes a power inlet connector 14 that permits the battery pack 12 to electrically and mechanically connect to perform two functions. The first function of the power inlet connector 14 is to provide a charging port for the battery 26 of the battery pack 12, and the second function of the power inlet connector 14 is to provide power to a secondary tool 3, as discussed below.

[0021] The battery 26 may include one or more electrochemical cells. The cells may be, for example, Li-Ion cylindrical cells, LiPo pouch cells or any other type of cell appropriate for a given application.

[0022] The CM ECU 24 is used for safely charging the cells of the battery 26. The CM ECU 24 regulates charge current, battery voltage, single cell monitoring, and operates only within battery temperature limits and can be realized with an off-the-shelf charge management integrated circuit (IC). When a primary tool 2 is attached to the battery pack 12, the CM ECU 24 can provide to the load (for example, to the tool motor 6) a current of up to the allowable charge current of the battery 26.

[0023] The discharge control device 22 may be an electronic switch (e.g., a MOSFET) controlled by the MCU 20 for discharge management of power provided to the secondary tool.The MCU 20 communicates with the CM ECU 24, provides discharge management control, and can communicate with a connected primary tool 2.

[0024] Referring to Fig. 2, a second power supply configuration for a battery-operated cordless power tool includes the cordless power tool 2 and the battery pack 12 of Fig. 1. In addition, the second power supply configuration includes a power supply 40 that is directly connected to the battery pack 12. In particular, a connector 42 of the power supply 40 electrically and mechanically engages a connector 14 of the battery pack 12.

[0025] In the illustrated embodiment, the power supply 40 is an AC / DC converter that steps down mains voltage to DC voltage that can be used by the cordless power tool 2 and / or a charging circuit. In the illustrated embodiment, the power supply 40 is a 60W power supply (12.6 volt, 4.87 ampere) as this wattage is typically used in high volume for laptop computers and thus such power supplies are readily available. The power supply 40 includes the connector 42 that mates with a corresponding power inlet connector 14 in the battery pack 12.

[0026] The power supply 40 is connected by an electrically conductive wire 44 to mains voltage, via for example connection to a utility power outlet 5. The power supply 40 may charge the battery 26 of the battery pack 12, provide power to the motor 8 of the power tool 2, and / or both, depending on the size of the power supply 40. This configuration can extend tool application run times as compared to a power tool that is powered solely by the battery pack 12.

[0027] Referring to Fig. 3, a third power supply configuration for a battery-operated cordless power tool includes the power supply 40 of Fig. 2 and a low-power secondary tool 3 such as a glue pen. The secondary tool 3 may be compact in size with limited electronic functionality and may or may not contain a battery. In the third power supply configuration, the secondary tool 3 is directly connected to the power supply 40 via the connector 42. Since there is no battery contained in the secondary tool 3, the power supply 40 fully powers the secondary tool 3.

[0028] Referring to Fig. 4, a fourth power supply configuration for a battery-operated cordless power tool includes the low power secondary tool 3 of Fig. 3 along with the batterypack 12 of Fig. 1. The batery pack 12 is configured for use with the primary tool 2, and thus is capable of providing more power than is needed by the secondary tool 3. In the fourth power supply configuration, the secondary tool 3 is directly powered from the battery pack 12 through the power inlet connector 14 or “charging port” provided on the batery pack 12. As previously discussed, the batery pack 12 includes a Li-Ion battery discharge control device 22 to keep the cost of the secondary tool low.

[0029] Referring again to Fig. 5, a first exemplary power supply system 1 includes the stand-alone batery pack 12, a primary tool 2, the external power supply 40. Optionally, the power supply system 1 may also include a secondary tool 3. This is an example of a 12V system, but power supply system 1 can also be adapted to work with other voltages such as 4V, 8V, 18V, etc.

[0030] The batery pack 12 provides a path 32 for delivering power from the power supply 40 to the primary tool 2. In the power delivery path 32, power flows from the power inlet connector 14 to the CM ECU 24, from the CM ECU 24 to the batery 26 and from the batery 26 to the power outlet connector 16.

[0031] In the power supply system 1, the power supplied to the primary tool 2 by the batery 26 may be supplemented by the power supply 12. For example, when the batery pack 12 is connected to the power supply 40 (in this example having 60Watt / 12.6Volts / 5 Amp), if the primary tool 2 draws two Amps, the batery pack 12 is configured to supply two Amps to the primary tool 2 and to supply three Amps to the batery 26 whereby the batery 26 is charged. In a second example, if the primary tool 2 draws more current than is supplied by the power supply 40 or causes the power supply voltage to drop below the batery pack voltage, the battery 26 provides additional current to the primary tool 2. In other words, the load current is provided by both the battery pack 12 and the power supply 40 simultaneously.

[0032] The batery pack 12 provides another path 36 for delivering power to the secondary tool 3. In this embodiment, the secondary tool 3 is directly powered from the batery pack 12 through the power inlet connector 14 or “charging port” provided on the battery pack 12. In the power delivery path 36, power flows from the battery 26 to the discharge control device 22, from the discharge control device 22 to the power inlet connector 14. In some embodiments,an electrically conductive wire 9 provides a connection between the power inlet connector 14 and the secondary tool 3.

[0033] Referring to Fig. 6, a second exemplary power supply system 100 is similar system to the system of Fig. 5 except that the power supply system 100 of Fig. 6 includes an alternative embodiment battery pack 112. The battery pack 112 of Fig. 6 differs from the battery pack 12 of Fig. 5 since the battery pack 112 includes a power isolation device 28 between the battery 26 and power supply 40. The power isolation device 28 allows the power supply power to be transferred to the primary tool 2 directly without needing the power to be regulated by the CM ECU 24. The added benefits are that the power supply 40 can still provide power to the primary tool 2, even if battery charging is not allowed due charge temperature limits and that a power supply with much greater power can be used. The power isolation device 28 works together with a microcontroller, charging circuit, DC power supply. It contains at least one ideal diode implemented with a FET and Ideal Diode or ORing controller with the anode at the battery pack positive terminal and the cathode at the load interface (main battery interface block).

[0034] The battery pack 112 provides two different and parallel paths 132, 134 for delivering power from the power supply 40 to the primary tool 2. In the first power delivery path 132, power flows from the power inlet connector 14 to the CM ECU 24, from the CM ECU 24 to the battery 26 and from the battery 26 to the power outlet connector 16. In the second power delivery path 134, power flows from the power inlet connector 14 to the power isolation device 28 and from the power isolation device 28 to the power outlet connector 16. Thus, the battery pack 112 is configured to allow power to bypass the CM ECU 24 and pass through the power isolation device 28 to the primary tool 2, permitting a larger power supply (for example, greater than 60W) to be connected to the battery pack 112. As in the previous embodiment, both the battery 26 and the power supply 40 provide power to the primary tool 2 at the same time.

[0035] The CM ECU 24 may prevent the battery from charging in certain operating conditions. For example, in cases where the battery pack 12 is in an environment where temperatures are outside the charging temperature range of the battery 26 (i.e., outside of the range of 0 degrees Celsius to 45 degrees Celsius) the CM ECU 24 will prevent battery charging. In another example, the CM ECU 24 will prevent battery charging in cases where there is asystem operating problem. In conditions where the CM ECU 24 prevents battery charging, the primary tool 2 may still be supplied with power via the second power delivery path 134.

[0036] Like the previous embodiment, the battery pack 112 provides the path 36 for delivering power to the secondary tool 3. In this embodiment, the secondary tool 3 is directly powered from the battery pack 112 through the power inlet connector 14 provided on the battery pack 12. In the power delivery path 36, power flows from the battery 26 to the discharge control device 22, from the discharge control device 22 to the power inlet connector 14. In some embodiments, an electrically conductive wire 9 provides a connection between the power inlet connector 14 and the secondary tool 3.

[0037] Referring to Fig. 7, a third exemplary power supply system 200 is similar to the previously described systems 1, 100 and shows another variant in which the power supply 40 is omitted and replaced with a Universal Serial Bus (USB) device 240, for example a USB Type- C® device with USB Power Delivery (USB PD®). By doing so, higher power can be supplied to the battery pack 212 than may be supplied by the power supply 40. For example, in the illustrated embodiment, the USB-C device 240 may supply 240 Watts / 5V-48V / 5 Amp.

[0038] The third power supply system 200 differs from the above-described first and second power supply systems 1, 100 in that the battery pack 212 includes a USB Type-C connector 214 as the power inlet connector. In order to accommodate USB PD supported voltages, a DC-DC converter 30 is needed to handle a variety of voltages. In some embodiments, the DC-DC converter 30 is configured to handle voltages in a range of 5 volts to 48 volts coming in from the USB device 240 as well as to provide a fixed output voltage from the battery 26 to the secondary tool 3. In addition, the third power supply system includes an MCU 220 that is modified to accommodate the USB connection.

[0039] The battery pack 112 provides two different and parallel paths 232, 234 for delivering power from the power supply (e.g., the USB device 240) to the primary tool 2. In the first power delivery path 232, power flows from the USB Type-C connector 214 to the DC-DC converter 30, from the DC-DC converter 30 to the CM ECU 24, from the CM ECU 24 to the battery 26, from the battery 26 to the power isolation device 28 and from the power isolation device 28 to the power outlet connector 16. In the second power delivery path 234, power flowsfrom the USB Type-C connector 214 to the DC-DC converter 30, from the DC-DC converter 30 to the power isolation device 28 and from the power isolation device 28 to the power outlet connector 16. Thus, the battery pack 112 is configured to allow power to bypass the CM ECU 24 and pass through the power isolation device 28 to the primary tool 2, permitting a larger power supply (for example, greater than 60W) to be connected to the battery pack 112. As in the previous embodiment, both the battery 26 and the USB device 240 may provide power to the primary tool 2 at the same time.

[0040] The battery pack 112 can be used to charge a secondary tool 3 via the battery 26, the discharge management device 22, the DC-DC converter 30 and USB-C connector 214.

[0041] Referring to Fig. 8, a fourth exemplary power supply system 300 is similar to the previously described systems 1, 100, 200 and shows yet another variant in which USB-C with power delivery can be used for tools with integrated battery. For this system, an integrated battery device 310, similar to the battery packs 12, 112, 212 described above, is incorporated into the primary tool 302. In the illustrated embodiment, the integrated battery device 310 includes a USB Type-C connector 214, a DC-DC converter 30, a CM ECU 24, an MCU 220 modified to accommodate the USB connection, a power isolator 28, and a battery 26.

[0042] The integrated battery device 310 provides two different and parallel paths 332, 334 for delivering power from the power supply (e.g., USB device 240) to the primary tool 2. In the first power path 332, power flows from the USB Type-C connector 214 to the DC-DC converter 30, from the DC-DC converter 30 to the CM ECU 24, from the CM ECU 24 to the battery 26, from the battery 26 to the power isolation device 28 and from the power isolation device 28 to the motor electronic control unit (motor ECU) 6. In the second power path 334, power flows from the USB Type-C connector 214 to the DC-DC converter 30, from the DC-DC converter 30 to the power isolation device 28 and from the power isolation device 28 to the motor electronic control unit (motor ECU) 6. Thus, the battery pack 212 is configured to allow power to bypass the CM ECU 24 and pass through the power isolation device 28 to the motor 8, permitting a larger power supply (for example, greater than 60W) to be connected to the motor 8. As in the previous embodiment, both the battery 26 and the power supply 240 may provide power to the primary tool 2 at the same time.

[0043] The integrated battery device 310 can be used to charge a secondary tool 3 via the USB-C connector 214.

[0044] Selective illustrative embodiments of the system and associated devices are described above in some detail. It should be understood that only structures considered necessary for clarifying the system and associated devices have been described herein. Other conventional structures, and those of ancillary and auxiliary components of the system, are assumed to be known and understood by those skilled in the art. Moreover, while working examples of the system and associated devices have been described above, the system and associated devices are not limited to the working examples described above, but various design alterations may be carried out without departing from the system and associated devices as set forth in the claims.

Claims

CLAIMS1. A batery supply system comprising: a power supply; a batery pack comprising a first connector and a second connector; and a cordless, batery powered power tool, wherein the batery supply system is configured to operate in a first mode in which the batery pack can discharge through the first connector, the second connector or both the first and second connector, in a second mode in which the batery pack is not discharging and the batery pack is charging, and in a third mode, and wherein when operating in the third mode and when a current demand resulting from a tool load through the first connector and / or the second connector can be provided by the power supply at a voltage higher than the battery pack voltage, the power supply simultaneously provides current to the tool and charges the battery pack, and when a current demanded resulting from a tool load through the first connector and / or the second connector is greater than a current limit of the power supply or causes a voltage of the power supply to drop below a voltage of the battery pack, the battery pack and the power supply simultaneously provide current to the tool.

2. A batery pack for supplying power to a battery powered device, the batery pack comprising: an inlet interface that is configured to be connected to a power supply, an outlet interface that is configured to be connected to a battery powered device, a first power supply path that transmits power from the inlet interface to the outlet interface, anda second power supply path that transmits power from the inlet interface to the outlet interface, wherein the first power supply path is different from the second power supply path, and the first power supply path and the second power supply path operate in parallel.

3. The battery pack of claim 2, wherein the first power supply path comprises: a charge management electronic control unit (CM ECU) that is connected to the inlet interface; and a battery that is disposed in the path between the CM ECU and the outlet interface.

4. The battery pack of claim 3, where the battery is configured to be charged by the power supply when the power supply is connected to the inlet interface.

5. The battery pack of claim 3, wherein the battery pack comprises a discharge controller that receives power from the battery and delivers it to the inlet interface.

6. The battery pack of claim 5, wherein the discharge controller is configured to provide at least one of under-voltage protection and over-current protection of the battery.

7. The battery pack of claim 2, wherein the second power supply path comprises: a power isolation device that is disposed between the inlet interface and the outlet interface.

8. A power supply system, comprising: a power supply;a batery powered device; and a batery pack that includes an inlet interface that is configured to be connected to the power supply, an outlet interface that is configured to be connected to the batery powered device, a first power supply path that transmits power from the inlet interface to the outlet interface, and a second power supply path that transmits power from the inlet interface to the outlet interface, wherein the first power supply path is different from the second power supply path, and the first power supply path and the second power supply path operate in parallel.

9. The power supply system of claim 8, wherein the first power supply path comprises: a charge management electronic control unit (CM ECU) that is connected to the inlet interface; and a batery that is disposed in the path between the CM ECU and the outlet interface.

10. The power supply system of claim 9, where the battery is configured to be charged by the power supply when the power supply is connected to the inlet interface.

11. The power supply system of claim 9, wherein the battery pack comprises a discharge controller that receives power from the batery and delivers it to the inlet interface.

12. The power supply system of claim 11, wherein the discharge controller is configured to provide at least one of under-voltage protection and over-current protection of the battery.

13. The power supply system of claim 8, wherein the second power supply path comprises: a power isolation device that is disposed between the inlet interface and the outlet interface.

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