Communication method between electric tool and battery pack, and electric tool

Abstract

The present invention discloses a method for communicating between a power tool and a battery pack, and the power tool. The method includes the following steps: S1: connecting the power tool to one of a first type of battery pack and a second type of battery pack, and powering on the power tool's identification circuit; S2: the identification circuit sending a request signal to the battery pack via a third port; and S3: setting a waiting time for the identification circuit. If the identification circuit receives a response signal from the battery pack within the waiting time, it determines that the battery pack is the first type and controls the operation of the first circuit. Otherwise, it determines that the battery pack is the second type and controls the operation of the second circuit. This communication method and power tool enable the power tool to be compatible with the two most common battery packs currently available, greatly improving the ease of use of the power tool.

Description

Technical Field

[0001] The present invention relates to the field of electric tools, and in particular to a communication method between an electric tool and a battery pack, and the electric tool. Background Art

[0002] Most power tools on the market today are DC power tools, meaning they're powered by battery packs. These tools offer the advantages of portability and rechargeability. DC power tools come in a variety of battery pack types, including standard integrated charge-discharge protection, resistor-based battery packs, and separate charge-discharge protection.

[0003] like Figure 1 As shown in (a), (b), and (c), they correspond to three types of battery packs: integrated charge and discharge protection battery pack, identification resistor battery pack, and separate charge and discharge protection battery pack. Figure 1 As shown in (a), for a battery pack with integrated charging and discharging protection, the charging and discharging protection circuits of the battery pack are all set inside the battery pack, and the battery pack controls the charging and discharging protection. The battery pack and the power tool are only connected through the positive terminal and the negative terminal of the power supply, and the battery pack only provides power to the power tool. Figure 1 As shown in (b) of the figure, for the identification resistor battery pack, an identification resistor is set in the power tool. The battery pack and the power tool are connected only through the positive terminal of the power supply, the negative terminal of the power supply and the third terminal. The battery pack detects the parameters of the identification resistor in the power tool through the third terminal, thereby obtaining information about the power tool and automatically adjusting the overcurrent protection parameters based on the information obtained. Figure 1 As shown in (c), for the charge-discharge separation protection battery pack, the battery pack and the power tool are connected only through the positive power terminal, the negative power terminal and the communication terminal. The battery pack communicates with the power tool through the communication terminal, and the power tool controls the discharge protection according to the communication signal of the battery pack.

[0004] However, in existing technologies, a power tool can only be used with a battery pack of the same model or platform series, and cannot be used with different models or compatible battery packs. Obviously, the existing power supply mode of power tools has the problem of inflexibility. If the original battery pack of the power tool suddenly becomes unusable due to power loss or damage and there is no replacement battery pack of the same model or platform series, the power tool will not be able to work. Therefore, the problem of power tool compatibility with different battery packs in existing technologies needs to be solved urgently. Summary of the Invention

[0005] In order to address the deficiencies in the prior art, the present invention proposes a communication method between an electric tool and a battery pack and an electric tool, which can enable the electric tool to match and be compatible with different types of battery packs, greatly improving the convenience of use of the electric tool.

[0006] To achieve the above objectives, the communication method between the power tool and the battery pack of the present invention includes:

[0007] S1. The power tool is connected to one of the first type of battery pack and the second type of battery pack, and the identification circuit of the power tool is powered on.

[0008] S2. The identification circuit sends a request signal to the battery pack through the third port;

[0009] S3. The identification circuit sets a waiting time. If the identification circuit receives a response signal from the battery pack during the waiting time, it determines that the battery pack is a first type of battery pack, and the identification circuit controls the operation of the first circuit. Conversely, if the identification circuit does not receive a response signal from the battery pack during the waiting time, it determines that the battery pack is a second type of battery pack, and the identification circuit controls the operation of the second circuit.

[0010] In one embodiment, the first line and the second line operate in an alternative manner. In step S2 , the identification circuit sends a request signal to the battery pack using the first line or the second line.

[0011] In one embodiment, the first circuit includes a first electronic switch, and the second circuit includes a second electronic switch. In step S2, if the identification circuit uses the first circuit to send a request signal to the battery pack, the first IO port of the power tool MCU outputs a high level, and the first electronic switch connected thereto is opened. At the same time, the second IO port of the power tool MCU outputs a low level, and the second electronic switch connected thereto is closed; if the identification circuit uses the second circuit to send a request signal to the battery pack, the second IO port of the power tool MCU outputs a high level, and the second electronic switch is opened. At the same time, the first IO port of the power tool MCU outputs a low level, and the first electronic switch is closed.

[0012] In one embodiment, the first type of battery pack includes a first battery pack MCU and a third electronic switch, and the second type of battery pack includes a second battery pack MCU. In step S3, if the battery pack connected to the power tool is the first type, then when the first type of battery pack receives the request signal from the identification circuit, the first battery pack MCU sends a communication signal to the power tool through the third electronic switch connected thereto; if the battery pack connected to the power tool is the second type, then the second battery pack MCU does not send a response signal.

[0013] In one embodiment, in step S3, if the identification circuit uses the first line to send a request signal to the battery pack, the first ADC / IO port of the power tool MCU performs the task of receiving the battery pack response signal; if the identification circuit uses the second line to send a request signal to the battery pack, the second ADC port of the power tool MCU performs the task of receiving the battery pack response signal.

[0014] In one embodiment, the communication method also includes: when the identification circuit determines that the battery pack is a first type of battery pack, the first type of battery pack sends the battery pack parameter information to the power tool MCU through the third port, and at the same time, the power tool MCU sends the power tool parameter information to the first type of battery pack through the first ADC / IO port; when the identification circuit determines that the battery pack is a second type of battery pack, the second type of battery pack obtains the parameter information of the identification resistor set in the power tool identification circuit through the third port to obtain information of the power tool.

[0015] In one embodiment, the first circuit also includes a fourth electronic switch, and the second circuit also includes a fifth electronic switch. The fourth electronic switch and the fifth electronic switch are PNP and NPN combination transistors. The first electronic switch is connected to the first IO port of the power tool MCU through the fourth electronic switch, and the second electronic switch is connected to the second IO port of the power tool MCU through the fifth electronic switch. In step S2, when the first IO port of the power tool MCU outputs a high level, the fourth electronic switch is turned on and drives the first electronic switch to open with a driving voltage higher than that of the power tool MCU. When the second IO port of the power tool MCU outputs a high level, the fifth electronic switch is turned on and drives the second electronic switch to open with a driving voltage higher than that of the power tool MCU.

[0016] The present invention also proposes an electric tool, comprising three ports connected to a battery pack, the three ports including a positive terminal, a negative terminal, and a third port, and is characterized in that the electric tool includes a control board, the control board is provided with an identification circuit for identifying the type of the battery pack, the identification circuit includes an electric tool MCU, a first circuit, and a second circuit, the first circuit includes a first electronic switch, the first electronic switch is connected to the first IO port and the first ADC / IO port of the electric tool MCU, the second circuit includes a second electronic switch, the second electronic switch is connected to the second IO port and the second ADC port of the electric tool MCU, and the second circuit also has an identification resistor, which is connected to the second electronic switch.

[0017] In one embodiment, when the identification circuit determines that the battery pack is a first type of battery pack, the identification circuit controls the first circuit to operate; when the identification circuit determines that the battery pack is a second type of battery pack, the identification circuit controls the second circuit to operate.

[0018] In one embodiment, the first type of battery pack includes a first battery pack MCU and a third electronic switch, and the third electronic switch is connected to the IO port of the first battery pack MCU; the second type of battery pack includes a second battery pack MCU.

[0019] In one embodiment, the first circuit also includes a fourth electronic switch, and the second circuit also includes a fifth electronic switch. The fourth electronic switch and the fifth electronic switch are PNP and NPN combination transistors. The first electronic switch is connected to the first IO port of the power tool MCU through the fourth electronic switch, and the second electronic switch is connected to the second IO port of the power tool MCU through the fifth electronic switch. The bases of the NPN transistors of the fourth electronic switch and the fifth electronic switch are connected to the first IO port and the second IO port respectively, and the emitters of the PNP transistors of the fourth electronic switch and the fifth electronic switch are connected to the external power supply.

[0020] Beneficial effects:

[0021] The present invention redesigns the control circuit of the power tool so that it includes two circuits and has the function of identifying the type of battery pack. When the battery pack is connected to the power tool, the control circuit first identifies the type of battery pack through the communication method of the present invention, and then controls the circuit corresponding to the type of battery pack to operate, so that the power tool of the present invention can match and be compatible with the two most common battery packs on the market, greatly improving the convenience of use of the power tool. In addition, the present invention adds a PNP and NPN combination transistor to the driving of the first electronic switch and the second electronic switch, so that the first electronic switch and the second electronic switch can be driven by an external power supply voltage higher than the MCU driving voltage, so as to solve the problem of unstable operation of the electronic switch caused by insufficient MCU driving voltage, thereby ensuring the effective driving of the first electronic switch and the second electronic switch, and also improving the stability and accuracy of the entire identification communication circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described and explained below in conjunction with the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the matching of three types of battery packs and power tools in the prior art.

[0024] Figure 2 This is a schematic diagram of the adaptation of the power tool and the battery pack according to the preferred embodiment of the present invention.

[0025] Figure 3 yes Figure 2 Circuit diagram of the first type of battery pack.

[0026] Figure 4 yes Figure 2 Circuit diagram of the second type of battery pack.

[0027] Figure 5 yes Figure 2 Circuit diagram of the control circuit of the power tool.

[0028] Figure 6This is the circuit diagram when the power tool is matched with two battery packs.

[0029] Reference numerals:

[0030] 10. Power tool; 11. Positive terminal of power tool; 12. Negative terminal of power tool; 13. Third terminal of power tool; 21. First type battery pack; 22. Second type battery pack; 211. Positive power terminal of first type battery pack; 212. Negative power terminal of first type battery pack; 213. Communication terminal of first type battery pack; 221. Positive power terminal of second type battery pack; 222. Negative power terminal of second type battery pack; 223. Third terminal of second type battery pack; 5. Identification circuit; 51. First circuit; 52. Second circuit; Q1. First electronic switch; Q2. Second electronic switch; Q3. Third electronic switch; Q4. Fourth electronic switch; Q5. Fifth electronic switch; MCU IO1. First IO port of power tool MCU; MCU IO2. Second IO port of power tool MCU; MCU ADC / IO1. First ADC / IO port of power tool MCU; MCU ADC2. Second ADC port of power tool MCU; R-ID. Identification resistor. DETAILED DESCRIPTION

[0031] The technical solutions of the present invention will be more clearly and completely explained below through description of preferred embodiments of the present invention in conjunction with the accompanying drawings.

[0032] The present invention discloses a communication method between an electric tool and a battery pack and an electric tool, the purpose of which is to solve the problem in the prior art that electric tools cannot match and be compatible with different types of battery packs.

[0033] like Figures 2 to 6 As shown, using the power tool and communication method of the present invention, the power tool 10 is compatible with and compatible with a first type of battery pack 21 and a second type of battery pack 22. These two types of battery packs are commonly found on the market. By redesigning the control circuit of the power tool, the present invention enables the power tool to be compatible with both types of battery packs, thereby improving the convenience of use of the power tool.

[0034] like Figure 3As shown, the first type of battery pack 21 has three ports, namely a positive power supply terminal 211, a negative power supply terminal 212, and a communication terminal 213. The control circuit of the first type of battery pack 21 includes a first battery pack MCU and a third electronic switch Q3. The third electronic switch Q3 is connected to the IO port and ADC / IO port of the first battery pack MCU, and is also connected to the communication terminal 213. Specifically, the third electronic switch Q3 is a transistor, whose base is connected to the IO port of the first battery pack MCU, the collector is connected to the communication terminal 213, and is connected to the ADC / IO port through a resistor R5. This first type of battery pack 21 is also called a "charge-discharge separation protection battery pack", that is, the charging protection circuit and the discharge protection circuit are separated from each other, the discharge protection circuit is set in the power tool, and the charging protection circuit is set in the charger. This type of battery pack can communicate with the power tool through the communication terminal 213 and can send its own parameter information to the power tool. The power tool controls the discharge protection according to the received parameter information.

[0035] like Figure 4 As shown, the second type of battery pack 22 includes three ports, namely the positive power supply terminal 221, the negative power supply terminal 222, and the third terminal 223. The control circuit of the second type of battery pack 22 includes a second battery pack MCU, which is connected to the third terminal 223. The second type of battery pack 22 is also called an "identification resistor battery pack". There is no communication terminal in the port of this type of battery pack, so it does not have a communication function. Its third terminal 223 serves as a detection terminal. In the prior art, the electric tool matched with this type of battery pack is internally provided with an identification resistor. The "identification resistor battery pack" detects the parameters of the identification resistor through the third terminal 223 as parameter information characterizing the electric tool, and automatically adjusts the overcurrent protection according to this parameter information.

[0036] The above two battery packs are the two most common battery packs on the market. They can only be compatible with their respective matching power tools and cannot be adapted to other types of power tools, thus causing inconvenience in use.

[0037] In order to solve the above problems existing in the prior art, the present invention redesigns the control circuit of the power tool to make it match and compatible with the above two battery packs. The following specifically introduces the power tool of the present invention and its communication method with the battery pack.

[0038] like Figure 5 As shown, the power tool 10 of the present invention includes three ports connected to the battery pack: a positive terminal 11, a negative terminal 12, and a third port 13. The power tool includes a control board, which is provided with an identification circuit 5 for identifying the type of the battery pack. The identification circuit 5 includes a power tool MCU, a first circuit 51, and a second circuit 52. The first circuit 51 and the second circuit 52 are both connected to the power tool MCU.

[0039] Specifically, the first circuit 51 includes a first electronic switch Q1 and a fourth electronic switch Q4. The first electronic switch Q1 is connected to the first IO port MCU IO1 of the power tool MCU via the fourth electronic switch Q4. More specifically, the first electronic switch Q1 is a MOS transistor, with its gate connected to the fourth electronic switch Q4 and its drain connected to the first ADC / IO port MCU ADC / IO1 of the power tool MCU via a resistor R11. Preferably, the fourth electronic switch Q4 is a PNP and NPN combination transistor, with the base of the PNP transistor connected to the collector of the NPN transistor, the base of the NPN transistor connected to the first IO port MCU IO1, the emitter of the NPN transistor connected to the negative power supply, the emitter of the PNP transistor connected to the external power supply VCC, and the collector of the PNP transistor connected to the gate of the first electronic switch Q1 via a resistor R6. In this preferred embodiment, a fourth electronic switch Q4 is provided between the first electronic switch Q1 and the first ADC / IO port. The fourth electronic switch Q4 is connected to an external power supply VCC. The external power supply VCC is typically 12V or 15V, while the voltage of the power tool MCU is typically 3.3V or 5V. This design enables the fourth electronic switch Q4 to provide a higher driving voltage to the gate of the first electronic switch Q1, thereby ensuring that the first electronic switch Q1 is effectively driven.

[0040] The second circuit 52 includes a second electronic switch Q2 and a fifth electronic switch Q5. The second electronic switch Q2 is connected to the second IO port MCU IO2 of the power tool MCU via the fifth electronic switch Q5. More specifically, the second electronic switch Q2 is a MOS transistor, with its gate connected to the fifth electronic switch Q5 and its source connected to the second ADC port MCU ADC2 of the power tool MCU via a diode D1 and a resistor R12. The source is also connected to an identification resistor R-ID and, through this identification resistor R-ID, to the negative power supply. The parameters of the identification resistor R-ID can be used to characterize parameter information of the power tool. Preferably, the fifth electronic switch Q5, like the fourth electronic switch Q4, is a PNP and NPN combination transistor. The base of the PNP transistor is connected to the collector of the NPN transistor, the base of the NPN transistor is connected to the second IO port MCU IO2, the emitter of the NPN transistor is connected to the negative power supply, the emitter of the PNP transistor is connected to the external power supply VCC, and the collector of the PNP transistor is connected to the gate of the second electronic switch Q2 via a resistor R2. The function of the fifth electronic switch Q5 is the same as that of the fourth electronic switch Q4 , that is, to provide a larger driving voltage for the second electronic switch Q2 to ensure that the second electronic switch Q2 is effectively driven.

[0041] The first circuit 51 and the second circuit 52 of the above-mentioned electric tool identification circuit 5 work in an alternative manner, that is, when one of the circuits is working, the other circuit is in a non-working state. Here, "working" and "non-working" respectively include high-level and low-level states. "Working" can be a high-level output state, and correspondingly, "non-working" can be a low-level output state.

[0042] like Figure 5 and Figure 6 As shown, when the power tool of the present invention is connected to a battery pack, the type of the battery pack is first determined, and then the circuit corresponding to the type of the battery pack is controlled to operate according to the result of the determination, thereby achieving matching and coordinated operation of the power tool and the battery pack.

[0043] When the power tool 10 of the present invention is connected to the battery pack, the communication method includes:

[0044] S1. The power tool 10 is connected to one of the first type battery pack 21 and the second type battery pack 22, and the identification circuit 5 of the power tool 10 is powered on.

[0045] S2, the identification circuit 5 sends a request signal to the battery pack through the third port 13;

[0046] S3. The identification circuit 5 sets a waiting time. If the identification circuit 5 receives a response signal from the battery pack during the waiting time, the battery pack is determined to be a first type battery pack 21, and the identification circuit controls the first circuit 51 to operate. Conversely, if the identification circuit 5 does not receive a response signal from the battery pack during the waiting time, the battery pack is determined to be a second type battery pack 22, and the identification circuit 5 controls the second circuit 52 to operate.

[0047] Furthermore, in step S2, the identification circuit 5 can send a request signal to the battery pack using the first line 51 or the second line 52. The first line 51 and the second line 52 operate in an alternative manner. If the identification circuit 5 uses the first line 51 to send a request signal to the battery pack, the first IO port MCU IO1 of the power tool MCU outputs a high level as the request signal. At this time, the NPN transistor of the fourth electronic switch Q4 is turned on and its pin 5 is pulled low, so that the PNP transistor is turned on, thereby using VCC to power the gate of the first electronic switch Q1, causing the first electronic switch Q1 to turn on. At the same time, the second IO port MCU IO2 of the power tool MCU outputs a low level, and the second electronic switch Q2 connected to it is turned off. In this case, the first ADC / IO port MCU ADC / IO 1 performs the task of receiving the battery pack response signal. If the identification circuit 5 uses the second line 52 to send a request signal to the battery pack, the second IO port MCU IO2 of the power tool MCU outputs a high level as the request signal. At this time, the NPN transistor of the fifth electronic switch Q5 is turned on and its pin 5 is pulled low, causing the PNP transistor to turn on, thereby using VCC to power the gate of the second electronic switch Q2, causing the second electronic switch Q2 to turn on. At the same time, the first IO port MCU IO2 of the power tool MCU IO1 outputs a low level, and the first electronic switch Q1 is turned off. In this case, the second ADC port MCU ADC2 performs the task of receiving the battery pack response signal.

[0048] Furthermore, in step S3, if the first type battery pack 21 is connected to the power tool 10, then when the first type battery pack 21 receives the request signal from the identification circuit 5, the first battery pack MCU sends a communication signal to the power tool via the third electronic switch Q3 connected thereto. This communication signal serves as a response signal. At this point, when the first ADC / IO port MCU ADC / IO 1 of the identification circuit 5 receives the response signal from the battery pack, it determines that the battery pack is a first type battery pack 21 with communication capabilities. The control circuit controls the operation of the first circuit 51, and the power tool 10 communicates with the battery pack via the first circuit 51. Specifically, the power tool MCU sends power tool parameter information to the first type battery pack 21 via the first ADC / IO port, thereby achieving matching and coordinated operation between the two. Preferably, the power tool MCU sends the power tool parameter information to the first type battery pack 21 via the first ADC / IO port in an asynchronous communication manner.

[0049] If a second-type battery pack 22 is connected to the power tool 10, since the second-type battery pack 22 lacks communication capabilities, the second-type battery pack MCU will not respond after the power tool 10 sends a request signal. If the identification circuit does not receive a response signal within a preset waiting time, it determines that the battery pack is a second-type battery pack 22. The control circuit activates the second circuit 52, and the power tool 10 connects to the battery pack via the second circuit 52. At this point, the second-type battery pack 22 can detect the parameter information of the identification resistor R-ID in the second circuit 52 via the third terminal 223 and automatically adjust its overcurrent protection based on this parameter information, thereby achieving matching and coordinated operation between the power tool 10 and the second-type battery pack 22.

[0050] The above-mentioned communication method between the power tool and the battery pack enables the power tool to first identify the type of the battery pack connected to it, and then control the corresponding circuit to connect with the battery pack based on the identification result, so that the power tool can be compatible with the two common battery packs on the market, greatly improving the convenience of using the power tool.

[0051] The above-described specific embodiments merely describe preferred embodiments of the present invention and do not limit the scope of protection of the present invention. Any modifications, substitutions, and improvements made to the technical solution of the present invention by a person skilled in the art based on the textual description and drawings provided herein, without departing from the design concept and spirit of the present invention, shall fall within the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

Claims

1. A method for communicating between a power tool and a battery pack, wherein the battery pack includes a first type of battery pack and a second type of battery pack, and the power tool is connected to the battery pack via three ports, wherein the three ports include a positive terminal, a negative terminal, and a third port, wherein: The electric tool has an identification circuit for identifying the type of the battery pack, and the identification circuit includes an electric tool MCU, a first circuit, and a second circuit. The communication method comprises: S1. The power tool is connected to one of the first type of battery pack and the second type of battery pack, and the identification circuit of the power tool is powered on; S2. The identification circuit sends a request signal to the battery pack through the third port; S3. The identification circuit sets a waiting time. If the identification circuit receives a response signal from the battery pack within the waiting time, it determines that the battery pack is a first type of battery pack, and the identification circuit controls the operation of the first circuit. Conversely, if the identification circuit does not receive a response signal from the battery pack within the waiting time, it determines that the battery pack is a second type of battery pack, and the identification circuit controls the operation of the second circuit.

2. The communication method between an electric tool and a battery pack according to claim 1, wherein: The first circuit and the second circuit operate in an alternative manner, In step S2 , the identification circuit sends a request signal to the battery pack using the first line or the second line.

3. The communication method between an electric tool and a battery pack according to claim 2, wherein: The first circuit includes a first electronic switch, the second circuit includes a second electronic switch, In step S2, if the identification circuit sends a request signal to the battery pack using the first line, the first IO port of the power tool MCU outputs a high level, and the first electronic switch connected thereto is turned on. Simultaneously, the second IO port of the power tool MCU outputs a low level, and the second electronic switch connected thereto is turned off. If the identification circuit uses the second line to send a request signal to the battery pack, the second IO port of the power tool MCU outputs a high level, and the second electronic switch is turned on. At the same time, the first IO port of the power tool MCU outputs a low level, and the first electronic switch is turned off.

4. The method for communication between a power tool and a battery pack according to claim 3, wherein: The first type of battery pack includes a first battery pack MCU and a third electronic switch, and the second type of battery pack includes a second battery pack MCU. In step S3, if the battery pack of the first type is connected to the power tool, then when the first type of battery pack receives the request signal from the identification circuit, the first battery pack MCU sends a communication signal to the power tool through the third electronic switch connected thereto; if the battery pack of the second type is connected to the power tool, then the second battery pack MCU does not send a response signal.

5. The communication method between an electric tool and a battery pack according to claim 4, wherein: In step S3, if the identification circuit sends a request signal to the battery pack using the first line, the first ADC / IO port of the power tool MCU performs the task of receiving the communication signal of the first type of battery pack; If the identification circuit uses the second line to send a request signal to the battery pack, the second ADC port of the power tool MCU performs the task of receiving a response signal from the battery pack.

6. The communication method between an electric tool and a battery pack according to claim 5, characterized in that: The communication method also includes: when the identification circuit determines that the battery pack is a first type of battery pack, the first type of battery pack sends the battery pack parameter information to the power tool MCU through the third port, and at the same time, the power tool MCU sends the power tool parameter information to the first type of battery pack through the first ADC / IO port; when the identification circuit determines that the battery pack is a second type of battery pack, the second type of battery pack obtains the parameter information of the identification resistor set in the power tool identification circuit through the third port to obtain information about the power tool.

7. The communication method between an electric tool and a battery pack according to claim 3, wherein: The first circuit further includes a fourth electronic switch, and the second circuit further includes a fifth electronic switch. The fourth electronic switch and the fifth electronic switch are a combination of a PNP and an NPN transistor. The first electronic switch is connected to the first IO port of the power tool MCU through the fourth electronic switch, and the second electronic switch is connected to the second IO port of the power tool MCU through the fifth electronic switch. In step S2, when the first IO port of the power tool MCU outputs a high level, the fourth electronic switch is turned on and drives the first electronic switch to open with a driving voltage higher than that of the power tool MCU. When the second IO port of the power tool MCU outputs a high level, the fifth electronic switch is turned on and drives the second electronic switch to open with a driving voltage higher than that of the power tool MCU.

8. An electric tool comprising three ports connected to a battery pack, wherein the three ports include a positive terminal, a negative terminal, and a third port, wherein: The electric tool includes a control board, the control board is provided with an identification circuit for identifying the type of the battery pack, the identification circuit includes an electric tool MCU, a first circuit, and a second circuit. The first circuit includes a first electronic switch, and the first electronic switch is connected to the first IO port and the first ADC / IO port of the power tool MCU. The second circuit includes a second electronic switch, and the second electronic switch is connected to the second IO port and the second ADC port of the power tool MCU. The second circuit further has an identification resistor, which is connected to the second electronic switch. The first electronic switch and the second electronic switch are connected in series, and a circuit connecting the first electronic switch and the second electronic switch in series is connected to the third port.

9. The electric tool according to claim 8, wherein: When the identification circuit determines that the battery pack is a first type of battery pack, the identification circuit controls the first circuit to operate; when the identification circuit determines that the battery pack is a second type of battery pack, the identification circuit controls the second circuit to operate.

10. The electric tool according to claim 9, wherein: The first type of battery pack includes a first battery pack MCU and a third electronic switch, and the third electronic switch is connected to the IO port of the first battery pack MCU; The second type of battery pack includes a second battery pack MCU.

11. The electric tool according to claim 8, wherein: The first circuit further includes a fourth electronic switch, and the second circuit further includes a fifth electronic switch. The fourth electronic switch and the fifth electronic switch are a combination of a PNP and an NPN transistor. The first electronic switch is connected to the first IO port of the power tool MCU through the fourth electronic switch, and the second electronic switch is connected to the second IO port of the power tool MCU through the fifth electronic switch. The bases of the NPN transistors of the fourth electronic switch and the fifth electronic switch are connected to the first IO port and the second IO port respectively, and the emitters of the PNP transistors of the fourth electronic switch and the fifth electronic switch are connected to an external power supply.

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