CN214255717U - Power-on protection circuit and electric tool - Google Patents
Power-on protection circuit and electric tool Download PDFInfo
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- CN214255717U CN214255717U CN202120019793.7U CN202120019793U CN214255717U CN 214255717 U CN214255717 U CN 214255717U CN 202120019793 U CN202120019793 U CN 202120019793U CN 214255717 U CN214255717 U CN 214255717U
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Abstract
A power-on protection circuit is connected with a positive electrode of an external power supply and a control module of an electric tool and comprises a first resistor, a second resistor and a third resistor which are connected in series, wherein the first resistor is electrically connected with the positive electrode of the external power supply, the third resistor is grounded, the control module is electrically connected into a circuit formed by connecting the second resistor and the third resistor in series, the resistance value of the first resistor is larger than or equal to ten times that of the second resistor, and the resistance value of the second resistor is larger than or equal to five times that of the third resistor; first resistance has first electric capacity in parallel, first electric capacity with the second resistance forms differential circuit, should go up electric protection circuit simple structure, the cost is lower, the reliability is higher, the utility model also provides an application should go up electric protection circuit's electric tool.
Description
[ technical field ] A method for producing a semiconductor device
The utility model relates to an electric tool control technical field especially relates to an go up electric protection circuit and electric tool.
[ background of the invention ]
The tool with battery as power source consists of mainly electric tool body and detachable and replaceable battery pack. The normal use mode is to close the power-on switch of the electric tool when the last use is finished, and when the battery pack is inserted again next time, the electric tool cannot be suddenly started, but if the power-on switch on the electric tool is closed at the moment, the electric tool can be suddenly started when the battery pack is inserted, and the tool may hurt the user or surrounding people and objects when the user is not in guard.
Accordingly, there is a need for a power-on protection circuit and a power tool that overcome the drawbacks of the prior art.
[ Utility model ] content
The utility model aims to provide a simple structure, the cost is lower, the higher last electric protection circuit and the electric tool of reliability.
The utility model provides a technical scheme that prior art problem adopted is: a power-on protection circuit is connected with a positive electrode of an external power supply and a control module of an electric tool and comprises a first resistor, a second resistor and a third resistor which are connected in series, wherein the first resistor is electrically connected with the positive electrode of the external power supply, the third resistor is grounded, the control module is electrically connected into a circuit formed by connecting the second resistor and the third resistor in series, the resistance value of the first resistor is larger than or equal to ten times that of the second resistor, and the resistance value of the second resistor is larger than or equal to five times that of the third resistor; the first resistor is connected with a first capacitor in parallel, and the first capacitor and the second resistor form a differential circuit.
Preferably, the third resistor is connected in parallel with a second capacitor for filtering, and a capacitance value of the first capacitor is greater than or equal to ten times a capacitance value of the second capacitor.
Preferably, the resistance value of the first resistor is equal to one hundred times the resistance value of the third resistor.
For solving the problem that prior art exists, the utility model also provides an electric tool uses foretell last electric protection circuit, electric tool is including connecting the anodal vary voltage module of external power supply and full-bridge drive circuit, the output of vary voltage module is connected electric tool's control module does the control module power supply, full-bridge drive circuit includes input, control end and output, the external power supply positive with be connected with the power switch between the input, control module connects control end and control full-bridge drive circuit switches on or breaks off, the output is connected with the motor.
Preferably, an electrolytic capacitor is connected in parallel to an input end of the full-bridge driving circuit, and the other end of the electrolytic capacitor is grounded.
Preferably, the control module detects a voltage from the third resistor to ground, and when a current flows across the third resistor to generate a voltage difference, the control module controls the full-bridge driving circuit to be switched off.
Preferably, the motor is a three-phase brushless motor, the full-bridge driving circuit comprises six switching tubes, and the control module controls the six switching tubes to be switched on or switched off to provide power for the motor.
Preferably, the electric tool further comprises a current detection unit, one end of the current detection unit is electrically connected with the bus of the full-bridge driving circuit, and the other end of the current detection unit is connected with the control module.
Preferably, the electric tool further comprises a voltage detection unit, one end of the voltage detection unit is electrically connected with the anode of the external power supply, and the other end of the voltage detection unit is connected with the control module.
Preferably, the control module is electrically connected to an operation amount switch, and the control module controls the duty ratio of the full-bridge driving circuit according to the operation amount switch so as to control the rotation speed of the motor.
Compared with the prior art, the utility model discloses following beneficial effect has: the voltage change is produced at the two ends of the first capacitor, the current flows through the series circuit formed by the first resistor, the second resistor and the third resistor, the pressure difference is produced at the two ends of the third resistor, the control module can detect the voltage from the third resistor to the ground, and then the full-bridge driving circuit is controlled to be switched off to start the power-on protection, no current flows through the motor, the motor can not rotate even if the power switch is in a closed state, and the electric tool is prevented from being suddenly started when the power switch is not directly inserted into the battery pack by switching off, so that the user or other people are injured.
[ description of the drawings ]
The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings:
fig. 1 is a circuit diagram of an electric power tool according to an embodiment of the present invention;
fig. 2 is a circuit diagram of a power-on protection circuit according to an embodiment of the present invention.
The meaning of the reference symbols in the figures:
1. the power-on protection circuit comprises a power-on protection circuit 2, a motor 3, an MCU (microprogrammed control Unit) controller 31, a current detection unit 32, a voltage detection unit 33, an operation quantity switch 34, a transformation module 35, full-bridge driving circuits Q1-Q6, switching tubes D1-D6, a parasitic diode S1, a power-on switch R1, a first resistor R2, a second resistor R3, a third resistor R4, a first voltage-dividing resistor R5, a second voltage-dividing resistor C1, a first capacitor C2, a second capacitor E, an electrolytic capacitor E
[ detailed description ] embodiments
The present invention will be described in further detail with reference to the accompanying drawings and embodiments.
Referring to fig. 1 and 2, an upper protection circuit 1 and an electric tool according to an embodiment of the present invention are shown, and please refer to fig. 1, where the upper protection circuit 1 is connected to a positive electrode of an external power source and a control module of the electric tool, the external power source is a battery pack, the upper protection circuit 1 includes a first resistor R1, a second resistor R2 and a third resistor R3 connected in series, the first resistor R1 is electrically connected to the positive electrode of the external power source, the third resistor R3 is grounded, and the control module is electrically connected to a circuit formed by connecting the second resistor R2 and the third resistor R3 in series; the resistance value of the first resistor R1 is greater than or equal to ten times that of the second resistor R2, and the resistance value of the second resistor R2 is greater than or equal to five times that of the third resistor R3; the first resistor R1 is connected in parallel with a first capacitor C1, the first capacitor C1 and the second resistor R2 form a differential circuit, and the first resistor R1 is used for providing a discharge loop for the first capacitor C1; the third resistor R3 is connected in parallel with a second capacitor C2 for filtering, and the capacitance value of the first capacitor C1 is greater than or equal to ten times the capacitance value of the second capacitor C2.
In this embodiment, the resistance of the first resistor R1 is equal to twenty times the resistance of the second resistor R2, the resistance of the first resistor R1 is equal to one hundred times the resistance of the third resistor R3, for example, the first resistor R1 is set to 2M Ω, the second resistor R2 is set to 100K Ω, the third resistor R3 is set to 20K Ω, the capacitance value of the first capacitor C1 is equal to ten times the capacitance value of the second capacitor C2, for example, the first capacitance C1 is set to 1uF, the second capacitance C2 is set to 0.1uF, when the power-on protection circuit 1 is electrically connected to the positive electrode of the external power source, voltage variation is generated at two ends of the first capacitor C1, the current flows through a series circuit consisting of the first resistor R1, the second resistor R2 and the third resistor R3, a voltage difference is generated across the third resistor R3, and the control module can detect the voltage across the third resistor R3 to ground.
The utility model also provides an use above-mentioned electric tool who goes up electric protection circuit 1, please refer to fig. 2, this electric tool is including connecting anodal vary voltage module 34 of external power supply and full-bridge drive circuit 35, the control module that the output of vary voltage module 34 is connected electric tool is the control module power supply, full-bridge drive circuit 35 includes input, control end and output, be connected with power-on switch S1 between the external power supply positive pole and the input, control module connects the control end and controls switching on or off of full-bridge drive circuit 35, the output is connected with motor 2, in this embodiment the control module sets up to MCU controller 3; the input end of the full-bridge driving circuit 35 is connected in parallel with an electrolytic capacitor E, the other end of the electrolytic capacitor E is grounded, the electrolytic capacitor E is used for conducting the power-on switch S1, and the full-bridge driving circuit 35 also conducts and instantly absorbs a part of the peak electromotive force generated by the motor 2, and in the embodiment, the electrolytic capacitor E is set to be 1000 uF.
The MCU controller 3 detects the voltage from the third resistor R3 to ground and, when a battery pack is inserted into the electric power tool, the current flows through the third resistor R3, the MCU controller 3 detects a voltage difference generated across the third resistor R3, controls the full-bridge driving circuit 35 to turn off the power-on protection, no current flows through the motor 2, the motor 2 does not rotate even if the power-on switch S1 is in the closed state, thereby preventing the power tool from being suddenly started when the power-on switch S1 is not opened and is directly inserted into a battery pack, the MCU controller 3 only judges whether power-on protection is needed when the battery pack is inserted into the electric tool, and in the subsequent use process of the electric tool, the power-up switch S1 opens or closes the MCU controller 3 and no longer initiates power-up protection.
The motor 2 is a three-phase brushless motor, the full-bridge driving circuit 35 includes six switching tubes Q1-Q6, the MCU controller 3 controls the six switching tubes Q1-Q6 to be turned on or off to provide power for the motor 2 to drive the motor 2 to operate, and the six switching tubes Q1-Q6 are respectively connected in parallel with six parasitic diodes D1-D6; the MCU controller 3 is electrically connected to an operation amount switch 33, and the MCU controller 3 controls the duty ratio of the full-bridge driving circuit 35 according to the operation amount switch 33 to control the rotation speed of the motor 2; the electric tool further comprises a current detection unit 31, wherein one end of the current detection unit 31 is electrically connected with the bus of the full-bridge driving circuit 35, and the other end of the current detection unit 31 is connected with the MCU controller 3; electric tool still includes voltage detection unit 32, voltage detection unit 32 one end electric connection external power supply's positive pole, the other end is connected MCU controller 3, voltage detection unit 32 includes series connection's first divider resistance R4 and second divider resistance R5, first divider resistance R4 electric connection external power supply's positive pole, second divider resistance R5 ground connection, MCU controller 3 electric connection first divider resistance R4 with second divider resistance R5 series connection's circuit, and detect second divider resistance R5 is to the voltage of ground, and then detect the voltage of the battery package that electric tool connects.
The present invention is not limited to the above-described embodiments. It will be readily appreciated by those skilled in the art that there are numerous alternatives to the power-on protection circuit and power tool of the present invention without departing from the principles and scope of the invention. The protection scope of the present invention is subject to the content of the claims.
Claims (10)
1. The utility model provides an go up electric protection circuit, connects external power source's positive pole and electric tool's control module, includes first resistance, second resistance and the third resistance of series connection, first resistance electric connection external power source's positive pole, third resistance ground connection, control module electrical property inserts in the circuit of second resistance with third resistance series connection, its characterized in that: the resistance value of the first resistor is greater than or equal to ten times that of the second resistor, and the resistance value of the second resistor is greater than or equal to five times that of the third resistor; the first resistor is connected with a first capacitor in parallel, and the first capacitor and the second resistor form a differential circuit.
2. The power-on protection circuit of claim 1, wherein: the third resistor is connected in parallel with a second capacitor for filtering, and the capacitance value of the first capacitor is larger than or equal to ten times that of the second capacitor.
3. The power-on protection circuit of claim 2, wherein: the resistance value of the first resistor is equal to one hundred times the resistance value of the third resistor.
4. A power tool, applying the power-on protection circuit of any one of claims 1-3, characterized in that: electric tool is including connecting anodal vary voltage module of external power source and full-bridge drive circuit, the output of vary voltage module is connected electric tool's control module does the control module power supply, full-bridge drive circuit includes input, control end and output, the external power source anodal with be connected with the power-on switch between the input, control module connects control end and control full-bridge drive circuit switches on or breaks off, the output is connected with the motor.
5. The power tool of claim 4, wherein: the input end of the full-bridge driving circuit is connected with an electrolytic capacitor in parallel, and the other end of the electrolytic capacitor is grounded.
6. The power tool of claim 4, wherein: the control module detects the voltage from the third resistor to the ground, and controls the full-bridge driving circuit to be switched off when the voltage difference is generated between the current passing through the two ends of the third resistor.
7. The power tool of claim 4, wherein: the motor is a three-phase brushless motor, the full-bridge driving circuit comprises six switching tubes, and the control module controls the six switching tubes to be switched on or switched off to supply power to the motor.
8. The power tool of claim 4, wherein: the electric tool further comprises a current detection unit, one end of the current detection unit is electrically connected with the bus of the full-bridge driving circuit, and the other end of the current detection unit is connected with the control module.
9. The power tool of claim 4, wherein: the electric tool further comprises a voltage detection unit, one end of the voltage detection unit is electrically connected with the anode of the external power supply, and the other end of the voltage detection unit is connected with the control module.
10. The power tool of claim 4, wherein: the control module is electrically connected with an operation quantity switch, and the control module controls the duty ratio of the full-bridge driving circuit according to the operation quantity switch so as to control the rotating speed of the motor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120019793.7U CN214255717U (en) | 2021-01-05 | 2021-01-05 | Power-on protection circuit and electric tool |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120019793.7U CN214255717U (en) | 2021-01-05 | 2021-01-05 | Power-on protection circuit and electric tool |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214255717U true CN214255717U (en) | 2021-09-21 |
Family
ID=77724150
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120019793.7U Active CN214255717U (en) | 2021-01-05 | 2021-01-05 | Power-on protection circuit and electric tool |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214255717U (en) |
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2021
- 2021-01-05 CN CN202120019793.7U patent/CN214255717U/en active Active
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