CN214506609U - Electric screwdriver and battery pack hardware protection circuit thereof - Google Patents
Electric screwdriver and battery pack hardware protection circuit thereof Download PDFInfo
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- CN214506609U CN214506609U CN202120667626.3U CN202120667626U CN214506609U CN 214506609 U CN214506609 U CN 214506609U CN 202120667626 U CN202120667626 U CN 202120667626U CN 214506609 U CN214506609 U CN 214506609U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The application provides an electric screwdriver and a battery pack hardware protection circuit thereof, wherein the battery pack hardware protection circuit comprises a battery protection chip, an MOSFET chip and first to sixth resistors; the DO end of the battery protection chip is connected to the first grid electrode of the MOSFET chip through the first resistor, the CO end of the battery protection chip is connected to the second grid electrode of the MOSFET chip through a third resistor, the VM end of the battery protection chip is connected to the ground end through a fifth resistor, the VDD end of the battery protection chip is connected to the positive electrode of a battery through the sixth resistor, and the VSS end of the battery protection chip is connected to the negative electrode of the battery; the first source of the MOSFET chip is connected to the battery cathode. The battery protection chip can detect the battery voltage between the positive electrode of the battery and the negative electrode of the battery by utilizing the VDD terminal and the VSS terminal, and the charging and discharging of the battery are automatically regulated and controlled by arranging the MOSFET chip and combining the voltage difference between the VM terminal and the VSS terminal, so that the safety and the reliability are higher.
Description
Technical Field
The application relates to the technical field of electric screwdrivers, in particular to an electric screwdriver and a battery pack hardware protection circuit thereof.
Background
The screwdriver is a tool for screwing a screw to force the screw to be in place, and generally comprises a thin wedge-shaped head (screwdriver bit) which can be inserted into a slot or a notch of a screw head and then is rotated to fix the screw at a specified position.
The conventional electric screwdriver is easily in an overcharged state, an overdischarged state, a short-circuit state or an overcurrent state during the charging and discharging processes of a battery. In the above state, if the charging or discharging of the battery is not stopped, the battery is damaged, and the safety and reliability are low.
Disclosure of Invention
The application aims to provide the electric screwdriver and the battery pack hardware protection circuit thereof, which can automatically regulate and control the charging and discharging of a battery, and have higher safety and reliability.
The purpose of the application is realized by adopting the following technical scheme:
in a first aspect, the present application provides a battery pack hardware protection circuit for an electric screwdriver, the battery pack hardware protection circuit including a battery protection chip, a MOSFET chip, and first to sixth resistors; the DO end of the battery protection chip is connected to the first grid electrode of the MOSFET chip through the first resistor, the DO end of the battery protection chip is further connected to the first source electrode of the MOSFET chip through a second resistor, the CO end of the battery protection chip is connected to the second grid electrode of the MOSFET chip through a third resistor, the CO end of the battery protection chip is further connected to the second source electrode of the MOSFET chip through a fourth resistor, the VM end of the battery protection chip is connected to a ground end through a fifth resistor, the VDD end of the battery protection chip is connected to the positive electrode of a battery through a sixth resistor, and the VSS end of the battery protection chip is connected to the negative electrode of the battery; the first source electrode of the MOSFET chip is connected to the negative electrode of the battery, the second source electrode of the MOSFET chip is connected to the grounding terminal, and the first drain electrode of the MOSFET chip is connected to the second drain electrode of the MOSFET chip. The technical scheme has the beneficial effects that on one hand, by arranging the first resistor to the fifth resistor, the first resistor and the third resistor can prevent surrounding components from being broken down due to the fact that the switching speed of the MOSFET chip is too high in a high-voltage state, the second resistor and the fourth resistor can be used as a discharge resistance to discharge a small amount of static electricity of the MOSFET chip, misoperation of the MOSFET chip is prevented, and the fifth resistor can play a role in limiting current; on the other hand, the VDD terminal of the battery protection chip may be connected to the positive electrode of the battery through a sixth resistor, and the sixth resistor may limit the input current of the VDD terminal of the battery protection chip, stabilize the voltage state of the VDD terminal of the battery protection chip, and enhance ESD protection. The VSS end of the battery protection chip can be connected to the cathode of the battery, therefore, the battery protection chip can detect the battery voltage between the anode of the battery and the cathode of the battery by utilizing the VDD end and the VSS end, the charging and discharging of the battery are automatically regulated and controlled by arranging the MOSFET chip and combining the voltage difference between the VM end and the VSS end, and the safety and the reliability are high.
When the voltage of the battery is above the overdischarge detection voltage and below the overcharge detection voltage, and the voltage difference between the VM end and the VSS end is above the charge overcurrent detection voltage and below the discharge overcurrent detection voltage, the CO end and the DO end both output high levels, the first source electrode and the first drain electrode of the MOSFET chip are conducted, the second source electrode and the second drain electrode are conducted, at the moment, the battery is in a normal working state, and charging and discharging can be freely carried out; in the charging process, when the voltage of the battery is greater than the overcharge detection voltage and the duration of the state is greater than the overcharge detection delay duration, the second source electrode and the second drain electrode of the MOSFET chip are not conducted, the charging is stopped, and at the moment, the battery is in an overcharge state; during the discharging process, when the battery voltage is reduced below the overdischarge detection voltage and the state lasts for a time period longer than the overdischarge detection delay time period, the first source and the first drain of the MOSFET chip are not conducted, the discharging is stopped, and at the moment, the battery is in the overdischarge state.
When the battery is in a normal working state, when the voltage difference between the VM end and the VSS end is greater than the discharge overcurrent detection voltage and the duration of the state is greater than the discharge overcurrent detection delay duration, the first source electrode and the first drain electrode of the MOSFET chip are not conducted, the discharge is stopped, and at the moment, the battery is in a discharge overcurrent state; when the voltage difference between the VM terminal and the VSS terminal is lower than the charging overcurrent detection voltage and the duration of the state is longer than the charging overcurrent detection delay duration, the second source electrode and the second drain electrode of the MOSFET chip are not conducted, the charging is stopped, and at the moment, the battery is in a charging overcurrent state.
In some optional embodiments, the battery pack hardware protection circuit further comprises a first capacitor; the first end of the first capacitor is connected between the sixth resistor and the VDD end of the battery protection chip, and the second end of the first capacitor is connected to the cathode of the battery. This technical scheme's beneficial effect lies in, through setting up first electric capacity, can filter the clutter, promotes the stability ability of the VDD end of battery protection chip.
In some optional embodiments, the battery pack hardware protection circuit further comprises a second capacitor; the first end of the second capacitor is connected between the sixth resistor and the VDD end of the battery protection chip, and the second end of the second capacitor is connected to the cathode of the battery. This technical scheme's beneficial effect lies in, through setting up the second electric capacity, can filter the clutter, promotes the stability ability of the VDD end of battery protection chip.
In some alternative embodiments, a ratio of a capacitance of the first capacitor to a capacitance of the second capacitor is greater than 10 and less than 30. The technical scheme has the beneficial effects that when the ratio of the capacitance of the first capacitor to the capacitance of the second capacitor is in a range of more than 10 and less than 30, the first capacitor has better capability of filtering low-frequency noise waves, and the second capacitor has better capability of filtering high-frequency noise waves; when the capacitance of the first capacitor is too large, the filtering effect can be weakened, the stability of the circuit is affected, and when the capacitance of the second capacitor is too small, the low-frequency clutter filtering effect of the circuit is poor.
In some optional embodiments, the MOSFET chip comprises a first MOSFET and a second MOs fet; the first MOSFET has the first gate, the first source, and the first drain; the second MOSFET has the second gate, the second source, and the second drain. The technical scheme has the advantages that the first grid electrode of the first MOSFET can be connected to the DO end of the battery protection chip through the first resistor, the first source electrode of the first MOSFET can be connected to the DO end of the battery protection chip through the second resistor, and the first MOSFET can be used as a discharge control switch; the second gate of the second MOSFET may be connected to the CO terminal of the battery protection chip through a third resistor, the second source of the second MOSFET may be connected to the CO terminal of the battery protection chip through a fourth resistor, and the second MOSFET may be used as a charge control switch.
In some alternative embodiments, the first MOSFET and the second MOSFET both employ an N-channel enhancement mode. The technical scheme has the advantages that the first MOSFET and the second MOSFET can adopt an N-channel enhancement type, the transconductance of the N-channel enhancement type MOSFET is large, and the working efficiency is high.
In some optional embodiments, the resistance value of the first resistor is the same as the resistance value of the third resistor. The beneficial effects of this technical scheme lie in, when the resistance of first resistance and the resistance of third resistance are different, the stability of circuit is relatively poor, consequently, can set up the resistance of first resistance to be the same with the resistance of third resistance, make circuit stability better.
In some optional embodiments, the resistance value of the second resistor is the same as the resistance value of the fourth resistor. The beneficial effects of this technical scheme lie in, when the resistance of second resistance and the resistance of fourth resistance are different, the stability of circuit is relatively poor, consequently, can set up the resistance of second resistance to be the same with the resistance of fourth resistance, make circuit stability better.
In some optional embodiments, the resistance value of the fifth resistor ranges from 300 Ω to 4K Ω, and the resistance value of the sixth resistor ranges from 300 Ω to 1K Ω. The beneficial effect of this technical scheme lies in, fifth resistance and sixth resistance can play the effect of current-limiting.
In a second aspect, the present application provides an electric screwdriver including the battery pack hardware protection circuit of any one of the electric screwdrivers described above. The technical scheme has the beneficial effects that the battery pack hardware protection circuit of the electric screwdriver can be applied to the electric screwdriver, so that the intelligent level of the electric screwdriver is improved.
Drawings
The present application is further described below with reference to the drawings and examples.
Fig. 1 is a schematic structural diagram of a battery pack hardware protection circuit of an electric screwdriver according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of an electric screwdriver provided in an embodiment of the present application.
In the figure: 10. a battery protection chip; 11. a DO terminal of the battery protection chip; 12. a VM end of the battery protection chip; 13. a CO end of the battery protection chip; 15. a VDD terminal of the battery protection chip; 16. a VSS terminal of the battery protection chip; 20. a MOSFET chip; s1, a first source electrode of the MOSFET chip; d1, a first drain of the MOSFET chip; s2, a second source electrode of the MOSFET chip; g2, second gate of MOSFET chip; d2, a second drain of the MOSFET chip; g1, a first gate of the MOSFET chip; r1, a first resistor; r2, a second resistor; r3, third resistor; r4, fourth resistor; r5, fifth resistor; r6, sixth resistor; c1, a first capacitance; c2, a second capacitance.
Detailed Description
The present application is further described with reference to the accompanying drawings and the detailed description, and it should be noted that, in the present application, the embodiments or technical features described below may be arbitrarily combined to form a new embodiment without conflict.
Referring to fig. 1, the present application provides a battery pack hardware protection circuit of an electric screwdriver, which includes a battery protection chip 10, a MOSFET chip 20, and first to sixth resistors R1 to R6; the DO terminal 11 of the battery protection chip is connected to the first grid G1 of the MOSFET chip through the first resistor R1, the DO terminal 11 of the battery protection chip is further connected to the first source S1 of the MOSFET chip through the second resistor R2, the CO terminal 13 of the battery protection chip is connected to the second grid G2 of the MOSFET chip through the third resistor R3, the CO terminal 13 of the battery protection chip is further connected to the second source S2 of the MOSFET chip through the fourth resistor R4, the VM terminal 12 of the battery protection chip is connected to the ground terminal through the fifth resistor R5, the VDD terminal 15 of the battery protection chip is connected to the positive pole of the battery through the sixth resistor R6, and the VSS terminal 16 of the battery protection chip is connected to the negative pole of the battery; the first source S1 of the MOSFET chip is connected to the negative electrode of the battery, the second source S2 of the MOSFET chip is connected to the ground terminal, and the first drain D1 of the MOSFET chip is connected to the second drain D2 of the MOSFET chip.
A Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), which is a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET).
The network label of the positive electrode of the battery is, for example, B +, the network label of the negative electrode of the battery is, for example, B-, and the network label of the ground terminal is, for example, GND.
The network label (net label) is an electrical connection point, generally composed of letters, symbols, numbers, etc., the electrical connection lines, pins and networks with the same network label are connected together, and the network labels are not connected.
In the embodiment of the present application, the selection of the battery protection chip 10 and the MOSFET chip 20 is not limited, the model of the battery protection chip 10 is, for example, HY2113-KB5B, and the model of the MOSFET chip 20 is, for example, DP 8205.
The battery protection chip 10 may include 6 pins, a pin 1 of the battery protection chip 10 is a DO terminal 11 of the battery protection chip, a pin 2 of the battery protection chip 10 is a VM terminal 12 of the battery protection chip, a pin 3 of the battery protection chip 10 is a CO terminal 13 of the battery protection chip, and a pin 5 of the battery protection chip 10 is a VDD terminal 15 of the battery protection chip; pin 6 of the battery protection chip 10 is the VSS terminal 16 of the battery protection chip.
The MOSFET chip 20 can include 6 pins, a 1 st pin of the MOSFET chip 20, i.e., the first source S1 of the MOS FET chip, a 2 nd pin of the MOSFET chip 20, i.e., the first drain D1 of the MOSFET chip, a 3 rd pin of the MOSFET chip 20, i.e., the second source S2 of the MOSFET chip, a 4 th pin of the MOSF ET chip 20, i.e., the second gate G2 of the MOSFET chip, a 5 th pin of the MOSFET chip 20, i.e., the second drain D2 of the MOSFET chip, and a 6 th pin of the MOSFET chip 20, i.e., the first gate G1 of the MOSF ET chip.
In the embodiment of the present application, the resistance values of the first resistor R1 to the sixth resistor R6 are not limited, and the resistance value of the first resistor R1 is, for example, 100 Ω, 150 Ω, or 200 Ω; the resistance of the second resistor R2 is, for example, 1M Ω, 1.5M Ω or 2M Ω; the resistance of the second resistor R2 is, for example, 100 Ω, 150 Ω or 200 Ω; the resistance of the fourth resistor R4 is, for example, 1M Ω, 1.5M Ω or 2M Ω; the resistance value of the fifth resistor R5 ranges from 300 omega to 4k omega; (ii) a The resistance value of the sixth resistor R6 ranges from 300 omega to 1K omega.
In a specific application, the resistance of the first resistor R1 may be the same as the resistance of the third resistor R3, for example, both are 100 Ω; the resistance of the second resistor R2 may be the same as the resistance of the fourth resistor R4, for example, 1M Ω.
Therefore, when the resistance value of the first resistor R1 is different from the resistance value of the third resistor R3, the stability of the circuit is poor, and therefore, the resistance value of the first resistor R1 can be set to be the same as the resistance value of the third resistor R3, so that the stability of the circuit is better; when the resistance of the second resistor R2 is different from the resistance of the fourth resistor R4, the stability of the circuit is poor, and therefore, the resistance of the second resistor R2 can be set to be the same as the resistance of the fourth resistor R4, so that the stability of the circuit is better.
Therefore, on one hand, by arranging the first resistor R1 to the fifth resistor R5, the first resistor R1 and the third resistor R3 can prevent surrounding components from being broken down due to the fact that the switching speed of the MOSFET chip 20 is too high in a high-voltage state, the second resistor R2 and the fourth resistor R4 can be used as a leakage resistance to discharge a small amount of static electricity of the MOSFET chip 20, misoperation of the MOSFET chip 20 is prevented, and the fifth resistor R5 can play a role in limiting current; on the other hand, the VDD terminal 15 of the battery protection chip may be connected to the positive electrode of the battery through a sixth resistor R6, and the sixth resistor R6 may limit the input current of the VDD terminal 15 of the battery protection chip, stabilize the voltage state of the VDD terminal 15 of the battery protection chip, and enhance ESD protection. The VSS terminal 16 of the battery protection chip can be connected to the negative electrode of the battery, so that the battery protection chip 10 can detect the battery voltage between the positive electrode of the battery and the negative electrode of the battery by using the VDD terminal 15 and the VSS terminal 16, and the MOSFET chip 20 is arranged to automatically regulate and control the charging and discharging of the battery in combination with the voltage difference between the VM terminal 12 and the VSS terminal 16, thereby having high safety and reliability.
When the battery voltage is above the over-discharge detection voltage and below the over-charge detection voltage, and the voltage difference between the VM terminal 12 and the VSS terminal 16 is above the charge over-current detection voltage and below the discharge over-current detection voltage, the CO terminal 13 and the DO terminal 11 both output a high level, the first source S1 of the MOSFET chip is conducted with the first drain D1, the second source S2 is conducted with the second drain D2, and at this time, the battery is in a normal operation state, and both charge and discharge can be performed freely; during the charging process, when the battery voltage is greater than the overcharge detection voltage and the duration of the state is greater than the overcharge detection delay duration, the second source S2 and the second drain D2 of the MOSFET chip are not conducted to stop the charging, and at this time, the battery is in the overcharge state; during the discharging process, when the battery voltage drops below the overdischarge detection voltage and this state continues for a time period longer than the overdischarge detection delay time period, the first source S1 and the first drain D1 of the MOSFET chip are not turned on to stop the discharging, and at this time, the battery is in an overdischarge state.
When the battery is in a normal working state, when the voltage difference between the VM terminal 12 and the VSS terminal 16 is greater than the discharging overcurrent detection voltage, and the duration of this state is greater than the discharging overcurrent detection delay duration, the first source S1 and the first drain D1 of the mosfet T chip are not turned on, and the discharging is stopped, at this time, the battery is in a discharging overcurrent state; when the voltage difference between the VM terminal 12 and the VSS terminal 16 is lower than the charging overcurrent detection voltage and the duration of this state is longer than the charging overcurrent detection delay duration, the second source S2 and the second drain D2 of the MOSFET chip are not turned on, and the charging is stopped, at this time, the battery is in a charging overcurrent state.
In some embodiments, the battery pack hardware protection circuit may further include a first capacitor C1; a first terminal of the first capacitor C1 may be connected between the sixth resistor R6 and the VDD terminal 15 of the battery protection chip, and a second terminal of the first capacitor C1 may be connected to the negative electrode of the battery.
The capacitance of the first capacitor C1 is not limited in the embodiments of the present application, and the capacitance of the first capacitor C1 is, for example, 0.01 μ F, 0.1 μ F, or 1 μ F.
Therefore, by arranging the first capacitor C1, noise waves can be filtered, and the stability of the VDD terminal 15 of the battery protection chip is improved.
In some embodiments, the battery pack hardware protection circuit may further include a second capacitor C2; a first terminal of the second capacitor C2 may be connected between the sixth resistor R6 and the VDD terminal 15 of the battery protection chip, and a second terminal of the second capacitor C2 may be connected to the negative electrode of the battery.
The capacity of the second capacitor C2 is not limited in the embodiments of the present application, and the capacity of the second capacitor C2 is, for example, 2 μ F, 2.2 μ F, or 3 μ F.
Therefore, by arranging the second capacitor C2, noise waves can be filtered, and the stability of the VDD terminal 15 of the battery protection chip is improved.
In a specific application, the ratio of the capacitance of the first capacitor C1 to the capacitance of the second capacitor C2 may be greater than 10 and less than 30. The capacitance of the first capacitor C1 is, for example, 0.1 μ F, and the capacitance of the second capacitor C2 is, for example, 2.2 μ F.
Therefore, when the ratio of the capacitance of the first capacitor C1 to the capacitance of the second capacitor C2 is greater than 10 and less than 30, the first capacitor C1 has better capability of filtering low-frequency noise, and the second capacitor C2 has better capability of filtering high-frequency noise; when the capacitance of the first capacitor C1 is too large, the filtering effect is weakened, and the stability of the circuit is affected, and when the capacitance of the second capacitor C2 is too small, the low-frequency noise filtering effect of the circuit is poor.
In some embodiments, the MOSFET die 20 may include a first MOSFET and a second MOSFET; the first MOSFET may have the first gate G1, the first source S1, and the first drain D1; the second MOSFET may have the second gate G2, the second source S2, and the second drain D2.
Thus, the MOSFET chip 20 may include a first MOSFET and a second MOSFET, the first gate G1 of the first MOSFET may be connected to the DO terminal 11 of the battery protection chip through a first resistor R1, the first source S1 of the first MOSFET may be connected to the DO terminal 11 of the battery protection chip through a second resistor R2, and the first MOSFET may function as a discharge control switch; the second gate G2 of the second MOSFET may be connected to the CO terminal 13 of the battery protection chip through a third resistor R3, the second source S2 of the second MOSFET may be connected to the CO terminal 13 of the battery protection chip through a fourth resistor R4, and the second MOSFET may be used as a charge control switch.
In a specific application, the first MOSFET and the second MOSFET may both employ an N-channel enhancement type.
Therefore, the first MOSFET and the second MOSFET can adopt an N-channel enhancement type, the transconductance of the N-channel enhancement type MOSFET is larger, and the working efficiency is higher.
In a specific application, the resistance of the fifth resistor R5 is in a range of 300 Ω -4K Ω, and is typically 2K Ω, and a larger value, such as 4K Ω, may be selected to control the current flowing when the charger is reversely connected.
The sixth resistor R6 has a resistance value in the range of 300 Ω -1K Ω, and typically 470 Ω, and may be selected to have a small value, for example, 300 Ω, in order to avoid a decrease in overcharge detection accuracy due to current consumption.
Therefore, the fifth resistor R5 and the sixth resistor R6 can play a role in limiting current.
Referring to fig. 2, the present application further provides an electric screwdriver, which includes any one of the above battery pack hardware protection circuits.
Therefore, the battery pack hardware protection circuit of the electric screwdriver can be applied to the electric screwdriver, and the intelligent level of the electric screwdriver is improved.
While the present application is described in terms of various aspects, including exemplary embodiments, the principles of the invention should not be limited to the disclosed embodiments, but are also intended to cover various modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. The battery pack hardware protection circuit of the electric screwdriver is characterized by comprising a battery protection chip, an MOSFET chip and first to sixth resistors;
the DO end of the battery protection chip is connected to the first grid electrode of the MOSFET chip through the first resistor, the DO end of the battery protection chip is further connected to the first source electrode of the MOSFET chip through a second resistor, the CO end of the battery protection chip is connected to the second grid electrode of the MOSFET chip through a third resistor, the CO end of the battery protection chip is further connected to the second source electrode of the MOSF ET chip through a fourth resistor, the VM end of the battery protection chip is connected to a ground end through a fifth resistor, the VDD end of the battery protection chip is connected to the positive electrode of a battery through a sixth resistor, and the VSS end of the battery protection chip is connected to the negative electrode of the battery;
the first source electrode of the MOSFET chip is connected to the cathode of the battery, the second source electrode of the MOSFET chip is connected to the grounding terminal, and the first drain electrode of the MOSFET chip is connected to the second drain electrode of the MOSF ET chip.
2. The battery pack hardware protection circuit of an electric screwdriver according to claim 1, further comprising a first capacitor;
the first end of the first capacitor is connected between the sixth resistor and the VDD end of the battery protection chip, and the second end of the first capacitor is connected to the cathode of the battery.
3. The battery pack hardware protection circuit of an electric screwdriver according to claim 2, further comprising a second capacitor;
the first end of the second capacitor is connected between the sixth resistor and the VDD end of the battery protection chip, and the second end of the second capacitor is connected to the cathode of the battery.
4. The battery pack hardware safeguard circuit of the electric screwdriver according to claim 3, wherein the ratio of the capacitance of the first capacitor to the capacitance of the second capacitor is greater than 10 and less than 30.
5. The battery pack hardware protection circuit of an electric screwdriver according to claim 1, wherein the MOSFET chip comprises a first MOSFET and a second MOSFET;
the first MOSFET has the first gate, the first source, and the first drain;
the second MOSFET has the second gate, the second source, and the second drain.
6. The battery pack hardware protection circuit of an electric screwdriver according to claim 5, wherein the first MOSFET and the second MOSFET are both of N-channel enhancement type.
7. The battery pack hardware protection circuit of an electric screwdriver according to claim 1, wherein the first resistor has the same resistance value as the third resistor.
8. The battery pack hardware protection circuit of an electric screwdriver according to claim 1, wherein the second resistor has the same resistance value as the fourth resistor.
9. The battery pack hardware protection circuit of the electric screwdriver according to claim 1, wherein the resistance value of the fifth resistor is in a range of 300 Ω -4K Ω, and the resistance value of the sixth resistor is in a range of 300 Ω -1K Ω.
10. An electric screwdriver, characterized in that it comprises a battery pack hardware protection circuit of an electric screwdriver according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120667626.3U CN214506609U (en) | 2021-03-31 | 2021-03-31 | Electric screwdriver and battery pack hardware protection circuit thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120667626.3U CN214506609U (en) | 2021-03-31 | 2021-03-31 | Electric screwdriver and battery pack hardware protection circuit thereof |
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| CN214506609U true CN214506609U (en) | 2021-10-26 |
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| CN202120667626.3U Active CN214506609U (en) | 2021-03-31 | 2021-03-31 | Electric screwdriver and battery pack hardware protection circuit thereof |
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- 2021-03-31 CN CN202120667626.3U patent/CN214506609U/en active Active
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