CN109980304A - Battery pack, current detection method and electric tool combination - Google Patents
Battery pack, current detection method and electric tool combination Download PDFInfo
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- CN109980304A CN109980304A CN201811589973.8A CN201811589973A CN109980304A CN 109980304 A CN109980304 A CN 109980304A CN 201811589973 A CN201811589973 A CN 201811589973A CN 109980304 A CN109980304 A CN 109980304A
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- battery pack
- resistance
- operational amplifier
- voltage
- amplifying circuit
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25F—COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR
- B25F5/00—Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4207—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells for several batteries or cells simultaneously or sequentially
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
- H01M10/4257—Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4285—Testing apparatus
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
- H01M10/482—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte for several batteries or cells simultaneously or sequentially
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M1/00—Analogue/digital conversion; Digital/analogue conversion
- H03M1/12—Analogue/digital converters
- H03M1/124—Sampling or signal conditioning arrangements specially adapted for A/D converters
- H03M1/1245—Details of sampling arrangements or methods
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
- H01M2010/4271—Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2220/00—Batteries for particular applications
- H01M2220/30—Batteries in portable systems, e.g. mobile phone, laptop
-
- 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
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Theoretical Computer Science (AREA)
- Mechanical Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Secondary Cells (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention discloses a battery pack, comprising: the electric tool comprises a shell, an adapting part used for connecting the electric tool, a battery pack and a battery management system, wherein the battery pack and the battery management system are accommodated in the shell; the battery management system comprises a current acquisition circuit and a current conversion circuit, wherein the input end of the current acquisition circuit is electrically connected with the output end of the current conversion circuit; wherein, the current conversion circuit includes: the conversion element is used for converting the current to be detected into the voltage to be detected; the first-stage amplifying circuit is used for inputting the voltage to be detected output by the conversion element; the n amplifying channels in the second-stage amplifying circuit are used for amplifying signals input by the input end of the second-stage amplifying circuit and outputting the signals from the corresponding output ends respectively. The invention also discloses a current detection method of the battery pack and an electric tool combination comprising the battery pack. The battery pack, the current detection method and the electric tool combination have the advantages that the sampling range and the sampling precision are higher, and the sampling randomness caused by the high frequency of the current to be detected in the sampling process is reduced.
Description
Technical field
The present invention relates to a kind of battery pack, electric current detecting method and electric tool combinations, more particularly to one kind to mention
Battery pack, electric current detecting method and the electric tool combination of high battery pack charging and discharging currents precision and range.
Background technique
Due to the ease of use of electric tool, will be used wider and wider, demanded power output is also higher and higher, because
This, the output current requirements for providing the battery pack of electric energy for electric tool are also more next big, in order to manage and monitor in battery pack
Battery pack conditions, using battery management system (BATTERY MANAGEMENT SYSTEM, BMS).In battery management system
(BMS) in, it is often necessary to which the electric current for sampling single battery is used to carry out overcurrent protection, calculates ampere-hour integral, estimation inside battery
Temperature estimates battery charge state (SOC) and health status (SOH) etc..Due to electric current and charger of the battery pack in charging
It is directly related, and electric current when discharging is then directly related with load.Especially battery pack to electric tool (for example, annular saw or
Electric drill) power supply when, the discharge current variation range of battery pack is big (peak value can reach 200 amperes even higher), and change frequency is high
(can reach tens KHz).These above-mentioned current characteristics for the battery pack of adaptation electric tool, to the detection accuracy of electric current and
More stringent requirements are proposed for range.For this reason, it may be necessary to provide a kind of battery pack suitable for electric tool, it can be improved battery and fill
The sampling precision of discharge current is able to solve the high bring sampling randomness of battery pack charging and discharging currents instantaneous value change frequency
The problem low with accuracy.
Summary of the invention
The present invention provides a kind of battery pack, electric current detecting method and electric tool combination, can be improved battery pack charge and discharge
The sampling precision and the high bring of solution battery charging and discharging current instantaneous value change frequency of electric current sample stochastic problems.
In order to achieve the above objectives, the present invention adopts the following technical scheme that:
In a first aspect, the embodiment of the present invention provides a kind of battery pack, it is suitable for electric tool, the battery pack includes:
Shell；
Locking portion, for connecting the electric tool, for electric tool power supply；
Battery pack is contained in the shell, and the battery pack is by multiple single batteries being connected in series or in parallel；
Battery management system is contained in the shell, and the battery management system includes current collection circuit and electric current conversion
Circuit, the input terminal of the current collection circuit are electrically connected with the output end of the current converter circuit, the current acquisition electricity
Road is used to acquire the electric current of the battery pack output；The current converter circuit includes:
Conversion element, the electric current to be detected for exporting the battery pack are converted into voltage to be detected；
First order amplifying circuit, the first order amplifying circuit are differential amplifier circuit, and the first order amplifying circuit includes two
A differential input end and output end, described two differential input ends connect with two voltage output ends of the conversion element respectively
It connects, for inputting the voltage to be detected of the conversion element output；
Second level amplifying circuit, including n amplification channel, input terminal and with the one-to-one n output end of n amplification channel；
The input terminal of the second level amplifying circuit is electrically connected with the output end of the first order amplifying circuit, and n amplification channel is used for
The signal that the input terminal of the second level amplifying circuit is inputted amplifies and exports respectively from corresponding output end, puts described in n
The corresponding sample range in channel greatly is different；Wherein, the corresponding sample range of the amplification channel is the second level amplifying circuit
When working in linear region, the range of the amplification channel output signal value, n is greater than 1 positive integer；
The current collection circuit includes n input terminal, n output of the n input terminal and the second level amplifying circuit
End corresponds electrical connection.
Specifically, the conversion element uses first resistor, and the first resistor is series in the circuit of slowdown monitoring circuit to be checked；
Two differential input ends of the first order amplifying circuit are connect with the both ends of the first resistor respectively.
Specifically, the first order amplifying circuit includes the first operational amplifier, second resistance, 3rd resistor, the 4th electricity
Resistance and the 5th resistance；
The positive input and reverse input end of first operational amplifier pass through the second resistance and the third respectively
Resistance is electrically connected with the both ends of the first resistor；The reverse input end is put by the 4th resistance with first operation
The output end electrical connection of big device；The positive input by the 5th resistance eutral grounding, first operational amplifier it is defeated
Outlet is connect with the input terminal of the second level amplifying circuit.
Specifically, between the reverse input end of first operational amplifier and the output end of first operational amplifier
It is electrically connected first capacitor.
Specifically, the second level amplifying circuit includes n second operational amplifier, n the 6th resistance and n the 7th electricity
Resistance；
The reverse input end of k-th of second operational amplifier passes through the 6th resistance of kth and the first order amplifying circuit
Output end electrical connection, is electrically connected k-th of the 7th resistance between the reverse input end and output end of k-th of second operational amplifier；
The positive input of the second operational amplifier is used for input reference voltage；
7th resistance of each second operational amplifier electrical connection and the ratio of the 6th resistance are different；
The reference voltage of the positive input input of each second operational amplifier is sequentially increased or is sequentially reduced；
Wherein k is the integer for being less than or equal to n more than or equal to 1.
Specifically, the second level amplifying circuit further includes n the 8th resistance and n the 9th resistance；
The positive input of k-th of second operational amplifier is connect by k-th of the 8th resistance with the first power supply, and is passed through
K-th of the 9th resistance eutral groundings；
8th resistance of each second operational amplifier electrical connection and the resistance value of the 9th resistance are different.
Specifically, the second operational amplifier further includes the first power input and the second fortune of second operational amplifier
The second source input terminal of amplifier is calculated, the first power supply (+Vcc) input terminal of the n second operational amplifiers is used for
Input the first supply voltage；The second source input terminal of first second operational amplifier is for inputting second source voltage
(- Vcc), remaining n-1 second operational amplifier second source input end grounding or input second source voltage (-
Vcc)。
Specifically, the battery pack further includes multiplexer；The multiplexer includes n paths input terminal and one
N output end of a channel output end, the n paths input terminal of the multiplexer and the second level amplifying circuit is one by one
Corresponding electrical connection；The channel output end of the multiplexer is electrically connected with the input terminal of the current collection circuit.
Second aspect, the embodiment of the invention also provides a kind of electric current detecting methods of above-mentioned battery pack, by institute of the present invention
Current collection circuit in the battery management system of offer executes, comprising:
The signal for sampling the n amplification channel output of the second level amplifying circuit one by one, obtains the sampling of n amplification channel
Value；
Judge the sampled value of each amplification channel whether in the corresponding sample range of the amplification channel；
If so, using the sampled value of the amplification channel as this current sampling data.
The third aspect, the embodiment of the invention also provides a kind of electric tool combination, including electric tool and as above-mentioned
The battery pack of embodiment, the battery pack can mount to the electric tool to provide electric energy for the electric tool, described
Electric tool includes: shell；Attachment, for realizing the function of the electric tool；Output shaft supports the tool attached
Part；Motor is contained in the shell, and the output shaft is driven to rotate for output driving power；The motor is operationally
It is connected to the output shaft；Battery pack engaging portion, for connecting the battery pack.
Electric current to be detected is converted into voltage to be detected by conversion element by the present invention, and voltage to be detected is carried out difference
Amplification carries out ratio enlargement to different sampled voltage ranges finally by n scaling circuit, solves the electronic work of adaptation
The charging and discharging currents change frequency of the battery pack of tool high bring sampling randomness and the low problem of accuracy, increase sampling model
It encloses, improves sampling precision.
Detailed description of the invention
Fig. 1 is a kind of structural schematic diagram of battery pack provided in an embodiment of the present invention；
Fig. 2 is a kind of structural schematic diagram of current detection circuit in the prior art；
Fig. 3 is a kind of waveform diagram of the discharge current of current detection circuit in the prior art；
Fig. 4 is a kind of structural schematic diagram of current converter circuit provided in an embodiment of the present invention；
Fig. 5 is the structural schematic diagram of another current converter circuit provided in an embodiment of the present invention；
Fig. 6 is the structural schematic diagram of another current converter circuit provided in an embodiment of the present invention；
Fig. 7 is the structural schematic diagram of another current converter circuit provided in an embodiment of the present invention；
Fig. 8 is a kind of structural schematic diagram of battery management system provided in an embodiment of the present invention；
Fig. 9 is the structural schematic diagram of another battery management system provided in an embodiment of the present invention；
Figure 10 is a kind of flow chart of electric current detecting method provided in an embodiment of the present invention；
Figure 11 is a kind of electric tool combination provided in an embodiment of the present invention；
Figure 12 is another electric tool combination provided in an embodiment of the present invention.
Specific embodiment
The present invention is described in further detail with reference to the accompanying drawings and examples.It is understood that this place is retouched
The specific embodiment stated is used only for explaining the present invention rather than limiting the invention.It also should be noted that in order to just
Only the parts related to the present invention are shown in description, attached drawing rather than entire infrastructure.
Battery pack 10 of the invention can be various types of battery packs, and battery pack 10 includes but is not limited to: shell 11；It is suitable
With portion 12, for connecting electric tool, for electric tool power supply；Battery pack 13 is contained in the shell, the electricity
Pond group includes multiple single batteries 131.
With reference to Fig. 1, battery pack 10 as an implementation, battery pack 10 includes but is not limited to: shell 11；Locking portion
12, for connecting electric tool, for electric tool power supply；Battery pack 13 is contained in the shell 11, the battery
Group 13 includes multiple single batteries 131, and each single battery 131 is connected in series or in parallel by connection component.
Wherein, battery pack 13 is the electric energy container that electric energy is stored in battery pack 10, can pass through electric energy and chemical energy phase
Mutually conversion storage or output electric energy, as an implementation, battery pack 13 by the electric energy of the compound containing elemental lithium and
Storage and output electric energy are realized in the conversion of chemical energy.Battery pack 13 stores electric energy when being electrically charged, battery pack 13 be connected to it is all
The electric energy that can be stored when such as electric tool electrical appliance is supplied to electrical appliance.
Battery pack 13 includes multiple single batteries 131, and each single battery 131 can provide certain electric energy, and have
Can physical connection positive and negative anodes, the positive and negative anodes of each single battery 131 are connected in series or are connected in parallel by connection component 132.
Single battery 131 can use cylindrical lithium electricity battery as shown in Figure 1.Battery pack 10 of the invention is suitable for electric tool,
Electric tool can be hand held electric tool, garden class tool, garden class vehicle such as vehicle type grass trimmer, herein not be
Limitation, electric tool includes but is not limited to the following contents: the electric tool of the needs speed regulation such as screwdriver, electric drill, spanner, angle mill,
Sander etc. may may be used to cut workpiece for the electric tool for workpiece of polishing, reciprocating saw, annular saw, sweep-saw etc.；Electric hammer
Etc. may be used to make the electric tool that uses of impact.These tools are also likely to be gardens class tool, such as pruner, chain saw；Separately
These outer tools may also be used as other purposes, such as blender.Battery pack 10 further includes circuit board (not shown), on circuit board
It is provided with circuit block, such as constitutes the circuit block of battery management system.The operation of battery pack 10 also relies on battery management
System, battery management system are contained in the shell 11 of battery pack 10, and specifically, at least partly component of battery management system is set
It is placed on the circuit board in above-mentioned battery pack 10.In battery management system (BMS), it is often necessary to sample the electric current of single battery
For carrying out overcurrent protection, calculating ampere-hour integral, estimation internal temperature of battery, battery charge state (SOC) and healthy shape are estimated
State (SOH) etc..Since electric current of the battery pack in charging is directly related with charger, and electric current when discharging then with load directly
Correlation, being especially adapted for use in the battery pack of electric tool, charging current and discharge current, there are bigger difference, charging currents
Generally it is up to 1C, maximum discharge current when normal work can reach 2C, in the case where loading biggish situation, maximum electric discharge
Electric current can reach 5C ~ 10C, and its charging current is generally up to 1C.
Fig. 2 is a kind of structural schematic diagram of current detection circuit in the prior art, as shown in Fig. 2, passing through transfer resistance
Electric current I to be detected is converted into voltage to be detected by Rs, and by voltage to be detected, (amplification factor is after differential amplifier circuit amplifies) be output to single-chip microcontroller and sampled.This current detection circuit is commonly used in the occasion not high to current sample required precision,
But for calculating ampere-hour integral, application, this detection method such as estimation SOC and SOH are no longer satisfied requirement.Fig. 3 is existing
There is the waveform diagram of the discharge current of one of technology current detection circuit, as shown in figure 3, the instantaneous value of discharge current changes frequency
Rate is high, and the often average value needed in BMS, the electric current of high frequency variation make the collected current signal of single-chip microcontroller random
Property is too high, cannot really reflect the average value of electric current.
Referring to Fig. 4, to solve the above problems, the present invention provides a kind of battery pack suitable for electric tool, cell tube
Reason system includes current collection circuit and current converter circuit, and the input terminal of the current collection circuit and electric current conversion are electric
The output end on road is electrically connected, and the current collection circuit is used to acquire the electric current of the battery pack output；The electric current conversion electricity
Road includes: conversion element 310, first order amplifying circuit 320 and second level amplifying circuit 330.
Conversion element 310 is used to electric current I to be detected being converted into voltage to be detected；
First order amplifying circuit 320 is differential amplifier circuit, including two differential input ends in1, in2 and output end out, two
Differential input end in1 and in2 are connect with two voltage output ends of conversion element 310 respectively, defeated for inputting conversion element 310
Voltage to be detected out.
Second level amplifying circuit 330, including n amplification channel 331, input terminal in3 and with n amplification channel 331 one by one
Corresponding n output end out1 to outn；The input terminal in3 of second level amplifying circuit 330 is defeated with first order amplifying circuit 320
Outlet out electrical connection, the signal that n amplification channel 331 is used to input the input terminal in3 of second level amplifying circuit 330 amplify
And exported respectively from corresponding output end, the n corresponding sample range of amplification channel 331 is different；Wherein, amplification channel is corresponding
When sample range is that second level amplifying circuit 330 works in linear region, the range of the amplification channel output signal value, n is big
In 1 positive integer.
Illustratively, conversion element 310 can use first resistor R1, first resistor R1 to be series at returning for slowdown monitoring circuit to be checked
Lu Zhong, specifically, the battery pack 13 that first resistor R1 is electrically connected composition with multiple single batteries 131 are connected in series.Therefore, first
The electric current flowed through on resistance R1 is the electric current I to be detected in slowdown monitoring circuit to be checked, when battery pack is connected on electric tool, to
Detection electric current I is the discharge current of battery pack 10.Fig. 4 is into Fig. 9, and electric current I to be detected is flowed out by battery pack 13, electricity to be detected
Stream I is discharge current, and certainly, when battery pack is connected to charger, electric current I to be detected flows to battery pack 130, electric current to be detected
For charging current.Two differential input ends in1 and in2 of first order amplifying circuit 320 connect with the both ends of first resistor R1 respectively
It connects.Electric current I to be detected is converted into voltage to be detected by first resistor R1, and the value of voltage to be detected is equal to the value of electric current I to be detected
With the product of the resistance value of first resistor R1.It should be noted that conversion element 310 is a kind of example using first resistor R1,
It is not the limitation to the embodiment of the present invention, such as in the other embodiments of the embodiment of the present invention, conversion element 310 can be with
Using Hall sensor.
First order amplifying circuit 320, i.e. the two of differential amplifier circuit differential input end in1 and in2 are electric with first respectively
The two voltage output ends connection for hindering R1 carries out differential amplification, Ke Yiti to voltage to be detected using first order amplifying circuit 320
The detection accuracy of high voltage to be detected.The input terminal of first order amplifying circuit 320 output end out and second level amplifying circuit 330
In3 connection, input of the input terminal of the n amplification channel 331 of second level amplifying circuit 330 with second level amplifying circuit 330
In3 connection is held, therefore the voltage input of 320 output end out of first order amplifying circuit output is into n amplification channel 331.
Voltage range that n amplification channel 331 can sample is different, therefore mutually not to the voltage sample of different voltages range
It influences, sample rate is fast.For example, the sample range of first amplification channel 331 is Umax (1) ~ Umax (2), second amplification
The sample range in channel 331 is Umax (2) ~ Umax (3), the sample range of n-th of amplification channel 331 is
Umax (n) ~ Umax(n+1).N amplification channel amplifies the signal of the input terminal in3 input of second level amplifying circuit, and
In synchronization, only one amplification channel, such as i-th of output channel (i is greater than the integer for being less than or equal to n equal to 1) are defeated
Voltage out is located within the scope of the use in the channel, and the voltage of other channels output is located at outside the use range in channel itself.
It can be using the voltage of i-th of amplification channel output, as this collected voltage.The n corresponding sampling of amplification channel 331
Range is the range of 331 output signal value of amplification channel when second level amplifying circuit 330 works in linear region.For example, first
The sample range of a amplification channel 331 is Umax (1) ~ Umax (2), and Umax (1) therein ~ Umax (2) is second level amplification electricity
Road works at linear region, the letter that first amplification channel 331 can input 330 input terminal in3 of second level amplifying circuit
The voltage model for number amplifying, and the voltage of amplified signal being exported from the output end out1 of first amplification channel 331
It encloses.
When electric current I to be detected is converted into voltage to be detected by first resistor R1, first order amplifying circuit 320 is to electricity to be detected
Pressure amplifies, and the signal of amplification is input to the n that different voltages sample range is corresponded in second level amplifying circuit 330 simultaneously
A amplification channel 331, second level amplifying circuit 330 amplify the signal that its input terminal in3 is inputted, and defeated from corresponding output end
Out.Since the sample range of each amplification channel is smaller, respectively less than entire 330 sample range of second level amplifying circuit.Such as the
330 output end of second amplifying circuit is with micro-control unit (Microcontroller Unit, MCU) using signal input part electricity
Connection, the signal that MCU exports second level amplifying circuit 330 sample, and the sampling resolution of MCU is 12, and the 1st amplification is logical
The sample range in road be Umax1 ~ Umax2, using MCU to the second level amplifying circuit output sample, be equivalent to by Umax1 ~
Umax2's is divided into 212=4096 parts.And the voltage range that can be exported for entire second level amplifying circuit be Umax1 ~
Umaxn is equivalent to Umax1 ~ Umaxn being divided into 4096 parts if directly sampled to it, the range of Umax1 ~ Umax2
Within the scope of Umax1 ~ Umaxn, sampling precision is improved.And for other amplification channels, sampling precision is mentioned
Height, therefore current converter circuit provided in an embodiment of the present invention is realizing sampling process, sampling precision improves.That is same
Under the sample range of sample, sampling precision is improved.
Electric current to be detected is converted into voltage to be detected by conversion element, using first by the technical solution of the present embodiment
Grade amplifying circuit amplifies voltage to be detected, improves the sampling precision of voltage to be detected.It is put by n in the amplifying circuit of the second level
Big channel can simultaneously sample the voltage of different voltages range, under same sampling precision, improve sample range.
Fig. 5 is the structural schematic diagram of another current converter circuit provided in an embodiment of the present invention, as shown in figure 5, this reality
Example is applied on the basis of the various embodiments described above, first order amplifying circuit 320 include the first operational amplifier N1, second resistance R2,
3rd resistor R3, the 4th resistance R4 and the 5th resistance R5.The positive input and reverse input end of first operational amplifier N1 with
It is electrically connected respectively by second resistance R2 and 3rd resistor R3 with the both ends of first resistor R1.First operational amplifier N1's is reversed
Input terminal is electrically connected by the 4th resistance R4 with the output end out of the first operational amplifier N1；First operational amplifier N1 is just
It is grounded to input terminal by the 5th resistance R5, the output end out of the first operational amplifier N1 is defeated with second level amplifying circuit 330
Enter in3 is held to connect.
As shown in figure 5, one end of second resistance R2 is connect with one end of first resistor R1, the other end and the first operation amplifier
The reverse input end of device N1 connects, and one end of the 4th resistance R4 is connect with the reverse input end of the first operational amplifier N1, another
End is connect with the output end out of the first operational amplifier N1, therefore second resistance R2 and the 4th resistance R4 are to voltage one to be detected
The difference of the output end out output voltage of the voltage value at end and the first operational amplifier N1 is divided, the first operational amplifier N1
Reverse input end input voltage value and the resistance value of the 4th resistance R4 it is related with the ratio of the resistance value of second resistance R2.Similarly,
3rd resistor R3 and the 5th resistance R5 divides the difference in voltage between the voltage value and ground line of the voltage other end to be detected
Pressure, the voltage value of positive input input of the first operational amplifier N1 and the resistance of the resistance value of the 5th resistance R5 and 3rd resistor R3
The ratio of value is related.And the signal of the first operational amplifier N1 amplification output is the positive input of the first operational amplifier N1
The difference of input voltage value and the voltage value of reverse input end input, therefore can be by adjusting the resistance value and the second electricity of the 4th resistance R4
It hinders the ratio of the resistance value of R2 or adjusts ratio the first operation of adjustment of the resistance value of the 5th resistance R5 and the resistance value of 3rd resistor R3
The voltage value of amplifier N1 output end out output.
The technical solution of the present embodiment, the ratio by adjusting the 4th resistance R4 and second resistance R2 adjust the first operation and put
The voltage value of the reverse input end input of the amplification factor and the first operational amplifier of big device, or by adjusting the 5th resistance
The voltage value that the positive input input of the first operational amplifier is adjusted with the ratio of 3rd resistor, can be in voltage to be detected
When voltage value changes, guarantee the input voltage of two differential input ends of first order amplifying circuit in first order amplifying circuit
In the range of linear work, to improve the sampling precision and sample range of voltage to be detected.
On the basis of above-mentioned each embodiment, with continued reference to Fig. 5, the reverse input end of the first operational amplifier N1 and
First capacitor C1 is electrically connected between the output end out of one operational amplifier N1.First capacitor C1 can be filtered out through the first operation
Higher harmonic component in the voltage signal of amplifier N1.
Fig. 6 is the structural schematic diagram of another current converter circuit provided in an embodiment of the present invention, as shown in fig. 6, this reality
Example is applied on the basis of the various embodiments described above, second level amplifying circuit 330 includes the 6th electricity of n second operational amplifier N2, n
Hinder R6 and n the 7th resistance R7；
The reverse input end of k-th of second operational amplifier N2 passes through k-th of the 6th resistance R6 and first order amplifying circuit 320
Output end out electrical connection, is electrically connected k-th the 7th between the reverse input end and output end of k-th of second operational amplifier N2
Resistance R7；The positive input of second operational amplifier N2 is used for input reference voltage；
The ratio of the 7th resistance R7 and the 6th resistance R6 of each second operational amplifier N2 electrical connection are different；
The reference voltage of the positive input input of each second operational amplifier N2 is sequentially increased or is sequentially reduced；
Wherein k is the integer for being less than or equal to n more than or equal to 1.
Further, second level amplifying circuit 330 further includes R8 and n the 9th resistance R9 of n the 8th resistance；
The positive input of k-th of second operational amplifier N2 is connect by k-th of the 8th resistance R8 with the first power supply, and is passed through
K-th of the 9th resistance R9 ground connection；
The resistance value of the 8th resistance R8 and the 9th resistance R9 of each second operational amplifier N2 electrical connection are different.
As shown in fig. 6, second level amplifying circuit 330 includes n amplification channel 331, each amplification channel 331 is at least by the
Two operational amplifier N2, the 6th resistance R6, the 7th resistance R7 composition.Each amplification channel 331 can also include the 8th resistance R8
With the 9th resistance R9.For convenience of explanation, the n amplification channel 331 that definition arranges from top to bottom is followed successively by the 1st to n-th and puts
Big channel, the second operational amplifier N2 arranged from top to bottom are followed successively by the 1st to n-th of second operational amplifier.
Second operational amplifier N2 in each amplification channel 331 positive input input reference voltage be sequentially increased or
Person is sequentially reduced.As shown in fig. 6, working as in second level amplifying circuit 330 within the scope of the corresponding voltage sample of different amplification channels 331
Voltage value it is ascending when, the reference of the positive input input of the second operational amplifier N2 in each amplification channel 331
Voltage is sequentially increased, the reference voltage of the positive input input of the second operational amplifier N2 in first amplification channel 331
The value of Vr1 is the minimum value in all reference voltages, and the forward direction of the second operational amplifier N2 in n-th of amplification channel 331 is defeated
The value for entering the reference voltage Vrn of end input is maximum value in all reference voltages, i.e. Vr1 < Vr2 < <
Vrn.When the voltage value in second level amplifying circuit 330 within the scope of the corresponding voltage sample of different amplification channels 331 is descending
When, the reference voltage of the positive input input of the second operational amplifier N2 in each amplification channel 331 is sequentially reduced, and first
The value of the reference voltage Vr1 of the positive input input of second operational amplifier N2 in a amplification channel 331 is all references
Maximum value in voltage, the reference voltage of the positive input input of the second operational amplifier N2 in n-th of amplification channel 331
The value of Vrn is the minimum value in all reference voltages, i.e. Vr1 > Vr2 > > Vrn, i.e. second operational amplifier
The reference voltage of the input of the positive input of N2 is different.
The positive input of k-th of second operational amplifier N2 is connect by k-th of the 8th resistance R8 with the first power supply, and
It is grounded by k-th of the 9th resistance R9.8th resistance R8 and the 9th resistance R9 divides the voltage of the first power input.When
Voltage value in second level amplifying circuit 330 within the scope of the corresponding voltage sample of different amplification channels 331 is ascending, i.e. and Vr1 <
When Vr2 < < Vrn, the 9th resistance R9 and the 8th of the 1st 331 to n-th amplification channel of amplification channel is set
The ratio of resistance R8 is ascending, thus in different amplification channels 331 positive input of second operational amplifier N2 ginseng
It examines voltage and meets Vr1 < Vr2 < < Vrn.When amplification channels 331 different in second level amplifying circuit 330 are corresponding
Voltage sample within the scope of voltage value it is descending, i.e. when Vr1 > Vr2 > > Vrn, the 9th resistance is set
The ratio of R9 and the 8th resistance R8 are descending, thus when keeping the voltage of the first power input equal, different amplification channels 331
The reference voltage of the positive input of middle second operational amplifier N2 meets Vr1 > Vr2 > > Vrn.
The reference voltage of the positive input input of second operational amplifier N2, corresponding includes second operational amplifier N2
Amplification channel 331 voltage sample range lower limit (minimum).For example, then it includes for the 1st amplification channel 331
Second operational amplifier N2 positive input input reference voltage be Umax (1), voltage sample range be Umax (1) ~
Umax(2).The voltage range that n amplification channel 331 samples is different, the forward direction of second operational amplifier N2 in amplification channel 331
The voltage value of the reference voltage of input terminal input is higher, and the lower limit of the voltage sample range of corresponding amplification channel 331 is (minimum
Value) it is higher.
The ratio of 7th resistance R7 and the 6th resistance R6 of amplification channel, for adjusting the sampling of second operational amplifier N2
The upper limit (maximum value) of range.Such as first second operational amplifier N2, corresponding sample range be Umax (1) ~
Umax (2), then Umax (2) is related to the ratio of the 7th resistance R7 and the 6th resistance R6.When the 1st to n-th amplification channel 331
The corresponding ascending arrangement of voltage sample range limit, i.e. Umax (1) < Umax (2) < < Umax (n).
Specifically, less than second amplification channel of the upper limit Umax (1) within the scope of the voltage sample of first amplification channel 331 at this time
The upper limit Umax (2) of 331 voltage sample range, therefore the 7th resistance R7 in the first amplification channel 331 and can be set
Ratio of the ratio of six resistance R6 less than the 7th resistance R7 and the 6th resistance R6 in second amplification channel 331.And so on,
The size relation of maximum voltage value within the scope of the corresponding voltage sample of different amplification channels 331 is Umax (1) < Umax (2)
When < < Umax (n), the 7th resistance R7 and the 6th resistance R6 in the 1st to n-th amplification channel 331 is set
Ratio is sequentially increased.Illustratively, the voltage sample range of the second operational amplifier N2 in first amplification channel 331 is
Umax (1) ~ Umax (2), when voltage of the voltage signal that first order amplifying circuit 320 exports less than first amplification channel 331
When minimum value Umax1 in sample range, the second operational amplifier N2 in first amplification channel 331 works in positive saturation region
Domain, the voltage inaccuracy that first order amplifying circuit 320 exports, cannot reflect the size of electric current.When first order amplifying circuit 320 is defeated
When voltage signal out is greater than the maximum value Umax2 within the scope of the voltage sample of first amplification channel 331, first amplification is logical
The voltage signal that second operational amplifier N2 work in road 331 is exported in negative zone of saturation, same first order amplifying circuit 320
Inaccuracy.Therefore the voltage sample range of first amplification channel 331 is Umax1 ~ Umax2.
By the sample range of each amplification channel of setting, keep the sample range in entire channel continuous, general each moment,
Only one second operational amplifier N2 output voltage values are located in the sample range of itself amplification channel, other second operations are put
The output voltage values of big device N2 are located at outside the sample range of itself amplification channel, can acquire output voltage values and be located at itself amplification
The voltage value of the second operational amplifier N2 output in channel, and using the voltage value as this sampled value.The skill of the present embodiment
Art scheme amplifies output to the signal of different voltage sample ranges by n amplification channel of second level amplifying circuit,
Under same sampling precision, sample range is improved.
It based on the above technical solution, further include the first power input with continued reference to Fig. 6, second operational amplifier N2
The first power input+VCC of end+VCC and second source input terminal-VCC, n second operational amplifier N2 are for inputting the
One voltage；Second source input terminal-the VCC of first second operational amplifier N2 is for inputting second voltage, and remaining n-1 the
Second source input terminal-the VCC of two operational amplifier N2 is grounded.
First electricity of the first power input+VCC and second source input terminal-the VCC input of second operational amplifier N2
Pressure and second voltage are related with the sampled voltage range of amplification channel 331.In order to make second operational amplifier N2 work linear
In region, the voltage value of positive input and the reverse input end input of second operational amplifier N2 is no more than the first power input
The first voltage and second voltage of end+VCC and second source input terminal-VCC input.Therefore, the sampled voltage of amplification channel 331
Range is in the range of the first voltage and second voltage that the first power input+VCC and second source input terminal-VCC is inputted.
One end of 8th resistance R8 and the first power electric connection, by the 8th resistance R8 and the 9th resistance R9 to the electricity of the first power input
After pressure is divided, the absolute value for the reference voltage for inputting the positive input of second operational amplifier N2 is put less than first
The absolute value of the second voltage of the second source input terminal-VCC input of second operational amplifier N2 in big channel 331.Pass through
After 7th resistance R7 and the 6th resistance R6 divides 320 output end out of the first order amplifying circuit voltage exported, make second
Less than first amplification channel 331 of voltage of the reverse input end input of second operational amplifier N2 in a amplification channel 331
In second operational amplifier N2 the first power input+VCC input first voltage, to make second operational amplifier N2
Work is in linear zone.Because the ratio of the different corresponding 8th resistance R8 and the 9th resistance R9 of amplification channel 331 is different, the 7th electricity
Second operational amplifier N2 work in the also different therefore different amplification channel 331 of the ratio of resistance R7 and the 6th resistance R6 exists
The corresponding positive input of linear zone is different with the voltage of reverse input end, the voltage model of the output end of second operational amplifier N2
Also difference is enclosed, to make the corresponding different voltage sample range of different amplification channels 331.And the 1st the second operation amplifier
Device N2 can convert the negative voltage of amplification, i.e., the lower limit of the sample range of the 1st second operational amplifier can be less than zero, accurately
Realize the amplification to negative voltage on conversion element in ground.
Based on the above technical solution, with continued reference to Fig. 6, the reverse input end of n second operational amplifier N2 with
The second capacitor C2 is electrically connected between the output end of second operational amplifier N2.And capacitor C2 can be filtered out and be put by the second operation
Higher harmonic component in the voltage signal of big device N2.
Fig. 7 is the structural schematic diagram of another current converter circuit provided in an embodiment of the present invention, as shown in fig. 7, first
Operational amplifier N1 and second operational amplifier N2 can be applied in current converter circuit simultaneously, i.e. first order amplifying circuit
320 include the first operational amplifier N1 while, second level amplifying circuit 330 include second operational amplifier N2, specifically connect
It is identical as the connection type of the first operational amplifier N1 and second operational amplifier N2 in Fig. 5 and Fig. 6 to connect mode, what is reached has
Beneficial effect is also identical, and details are not described herein again.
Fig. 8 is a kind of structural schematic diagram of 10 battery management system of battery pack provided in an embodiment of the present invention, such as Fig. 8
Shown, which includes current converter circuit provided by current collection circuit 340 and any embodiment.
Current collection circuit 340 includes n input terminal, n output end of n input terminal and second level amplifying circuit 330
Correspond electrical connection；
Wherein, n is greater than 1 positive integer.
Current converter circuit and current collection circuit 340 can be used for the charging and discharging currents using battery, realize to battery electricity
The monitoring of stream.Current collection circuit 340 is illustratively single-chip microcontroller, and single-chip microcontroller acquires n output of second level amplifying circuit 330
The voltage value for holding output, when the voltage in second level amplifying circuit 330 within the scope of the corresponding sampled voltage of different amplification channels 331
When being worth ascending, if the 1st voltage to the output of (i-1)-th amplification channel 331 is negative value, second operational amplifier N2
In negative zone of saturation, sampled voltage has exceeded the 1st within the scope of the sampled voltage of (i-1)-th amplification channel 331 for work, the
The voltage of i amplification channel 331 output is positive value, and second operational amplifier N2 works in linear region, and sampled voltage exists
Within the scope of the sampled voltage of i-th of amplification channel 331, single-chip microcontroller acquires the output end outi output of i-th of amplification channel 331
The current value of electric current to be detected is calculated according to obtained collection voltages as collection voltages in voltage.
It is logical to acquire different amplifications in second level amplifying circuit 330 by current collection circuit for the technical solution of the present embodiment
It is corresponding in the amplification channel of the sampled voltage range of amplification channel that the voltage of the corresponding output end in road 331 output chooses sampled voltage
The voltage of output end output improve sample range and sampling precision as collection voltages, and according to the voltage of collection voltages
The current value of electric current to be detected is calculated in value, can be convenient the current value for intuitively obtaining electric current to be detected.
Fig. 9 is the structural schematic diagram of another battery management system provided in an embodiment of the present invention.As shown in figure 9, the electricity
Pond management system includes that current collection circuit 360, current converter circuit and analog signal multichannel provided by any embodiment are multiple
With device 350.
Analog signal multiplexer 350 includes n paths input terminal and a channel output end, multiplexer 350
The n output end one-to-one correspondence of n paths input terminal and second level amplifying circuit 330 be electrically connected；Multiplexer 350 leads to
Road output end is electrically connected with the input terminal in4 of current collection circuit 360.
Wherein, n is greater than 1 positive integer.
One channel output end of multiplexer 350 is electrically connected with the input terminal in4 of current collection circuit 360, electric current
Acquisition Circuit 360 can be single-chip microcontroller, and single-chip microcontroller controls the selection of the n paths input terminal of multiplexer 350.Such as electric current
Acquisition Circuit 360 controls the conducting of the 1st paths of multiplexer by control terminal ctrl, i.e. the input terminal of the 1st paths and logical
It is connected between road output end, at this point, the 1st output end that current collection circuit 360 can acquire second level amplifying circuit 330 is defeated
Voltage out；Then current collection circuit 360 controls the conducting of the 2nd paths of multiplexer, i.e. the 2nd tunnel by control terminal ctrl
Path input and channel output end between be connected, at this point, current collection circuit 360 can acquire second level amplifying circuit
The voltage of 330 the 2nd output end output；In this way, current collection circuit 360 successively controls multiplexing by control terminal ctrl
The channel conductive of device realizes the voltage sample of the n output end output to second level amplifying circuit 330.
It should be noted that when the channel conductive all the way of multiplexer 350, the shutdown of other paths.Single-chip microcontroller root
The current value that electric current to be detected is calculated is carried out according to collection voltages.
Figure 10 is that a kind of electric current applied to the above-mentioned battery pack suitable for electric tool provided in an embodiment of the present invention is examined
The flow chart of survey method.As shown in Figure 10, the electric current detecting method is by electric in battery management system provided in an embodiment of the present invention
Acquisition Circuit is flowed to execute, comprising the following steps:
The signal that S110, n amplification channel for sampling second level amplifying circuit one by one export, obtains the sampling of n amplification channel
Value.
The signal of n amplification channel output end output in the amplifying circuit of the second level is sampled, it can be by the present invention
The current collection circuit that embodiment provides executes, and illustratively can be single-chip microcontroller.
S120, judge the sampled value of each amplification channel whether in the corresponding sample range of the amplification channel.
When the second operational amplifier in amplification channel works at linear region, the output valve of amplification channel is in the amplification
In the corresponding sample range in channel；When the second operational amplifier in amplification channel works in negative zone of saturation or positive zone of saturation
When, the output valve of amplification channel is not in the corresponding sample range of the amplification channel.
S130, if so, using the sampled value of the amplification channel as this current sampling data.
Electric current detecting method provided in an embodiment of the present invention chooses the output valve an of amplification channel as sampling each time
Value.The sample range of each amplification channel is respectively positioned on the voltage range of entire second amplifying circuit output, since the second level is amplified
The voltage range of circuit output is corresponding with the voltage range that first order amplifying circuit exports, and (second level amplifying circuit puts the first order
Big circuit output exports after amplifying, and voltage range is consistent).Directly acquisition first order amplifying circuit is defeated compared with the existing technology
Voltage value out improves the precision of sampling, has obtained more accurate current average.
The present invention also provides electric tool combinations in one, including electric tool and such as the battery in above embodiment
Packet, the battery pack can mount to the electric tool to provide electric energy for the electric tool, the electric tool include but
It is not limited to: shell；Attachment, for realizing the function of the electric tool；Output shaft supports the attachment；Motor,
It is contained in the shell, the output shaft is driven to rotate for output driving power；The motor operationally with it is described defeated
Axis connection out；Battery pack engaging portion, for connecting the battery pack.
Referring to Fig.1 1, electric tool combination as an implementation, the battery pack including being suitable for electric tool
110 and electric drill 20, battery pack 110 can mount to electric drill 20 to power for it.In the present embodiment, the knot of battery pack 110
Structure forms the battery pack 10 in similar above embodiment, and current acquisition is used at least in the battery management system of battery pack 110
Current converter circuit it is identical as the current converter circuit in battery pack 10.
Electric drill 20 is used as a kind of most common electric tool, is all for our daily lives and professional domain
A kind of very important tool.Electric drill 20 specifically includes that shell 21；Collet 23 and drill bit 22, brill of the drill bit 22 for drilling
Head；Collet 23 is for installing drill bit, the attachment of collet 23 and drill bit 22 as electric drill 22, for realizing the function of electric drill；
Output shaft (not shown) supports the drill bit 22；Motor (not shown) is contained in the shell 21, is used for output driving power
To drive the output shaft to rotate, so that collet 23 and drill bit 22 be driven to rotate；The motor operationally with the output shaft
Connection；Battery pack engaging portion, for connecting the battery pack 110.The main working principle of electric drill 20 is that electric current drives motor
Rotation, so that motor drives main axis to drive the collet 23 installed on output shaft to rotate, and collet 23 is equipped with drill bit,
Therefore, motor can bit to drill.
Electric drill 20 under case of heavy load, maximum impact electric current will be up to 100A even more than, the electric discharge of battery pack 110 electricity
It is big to flow variation range, and change frequency is high (can reach tens KHz).Fig. 2 and existing electric current detecting method shown in Fig. 3 cannot
Meet the current sample range and current detection accuracy of the battery pack of adaptation electric drill 20, and electronic work is suitable for using of the invention
Electric current to be detected is converted into voltage to be detected by conversion element by the battery pack of tool, using the first order amplifying circuit amplification to
Voltage is detected, the sampling precision of voltage to be detected is improved.It can be right simultaneously by n amplification channel in the amplifying circuit of the second level
The voltage of different voltages range is sampled, and under same sampling precision, improves sample range, can well solve electricity
The low problem of the sampling randomness and accuracy that rheology frequency high-band comes, increases sample range, improves sampling precision.
Referring to Fig.1 2, battery tool combination as another embodiment, the battery pack including being suitable for electric tool
120 and annular saw 30, battery pack 120 can mount to annular saw 30 as the power supply of annular saw 30.In the present embodiment, battery pack 120
Structure composition similar to the battery pack 10 in above embodiment, at least in the battery management system of battery pack 120 for electricity
The current converter circuit for flowing acquisition is identical as the current converter circuit in battery pack 10.
Annular saw 30 mainly includes bottom plate 31, casing 32, saw blade cover 33, saw blade axis 34, motor 35, transmission device 36.Its
In, bottom plate 31 includes the base plate plane for contacting with workpiece, and base plate plane extends along first axle direction；Casing 33 and bottom plate
31 connect and are fixed on above base plate plane；Saw blade cover 33 is connect with casing 33；Saw blade axis 34 is vertical with first direction, is used for
Saw blade rotation is supported to carry out cutting operation to workpiece to realize in saw blade cover 33；Motor 35 is set in casing 33, including fixed
Son and rotor, wherein stator includes winding, and the axis direction of motor 35 and first axle direction are in the same direction；Transmission device 36 is for connecting
Motor shaft 35 and saw blade axis 34 are connect, the rotary motion of motor 35 is conducted to the saw blade axis 34 to drive saw blade to operate.Battery
Packet 10 is used as power supply, for providing electric energy for annular saw 30.Annular saw 30 further includes circuit board and is arranged on circuit boards
The operating of circuit block, annular saw 30 need to rely on the circuit block being installed on circuit board.
Annular saw 30 under case of heavy load, maximum current will be up to 100A even more than, the discharge current of battery pack 120 becomes
It is big (peak value can reach 200 amperes even higher) to change range, and change frequency is high (can reach tens KHz).Shown in Fig. 2 and Fig. 3
Existing electric current detecting method be not able to satisfy adaptation electric drill 20 battery pack current sample range and current detection accuracy, and
Using the battery pack suitable for electric tool of the invention, electric current to be detected is converted by voltage to be detected by conversion element,
Voltage to be detected is amplified using first order amplifying circuit, improves the sampling precision of voltage to be detected.Pass through second level amplifying circuit
In n amplification channel can simultaneously the voltage of different voltages range is sampled, under same sampling precision, improve
Sample range can well solve the sampling randomness of curent change frequency high-band and the problem that accuracy is low, increase
Sample range improves sampling precision.
Note that the above is only a better embodiment of the present invention and the applied technical principle.It will be appreciated by those skilled in the art that
The invention is not limited to the specific embodiments described herein, be able to carry out for a person skilled in the art it is various it is apparent variation,
It readjusts and substitutes without departing from protection scope of the present invention.Therefore, although being carried out by above embodiments to the present invention
It is described in further detail, but the present invention is not limited to the above embodiments only, without departing from the inventive concept, also
It may include more other equivalent embodiments, and the scope of the invention is determined by the scope of the appended claims.
Claims (10)
1. a kind of battery pack, is suitable for electric tool, the battery pack includes:
Shell；
Locking portion, for connecting the electric tool, for electric tool power supply；
Battery pack is contained in the shell, and the battery pack is by multiple single batteries being connected in series or in parallel；
Battery management system is contained in the shell, and the battery management system includes current collection circuit and electric current conversion
Circuit, the input terminal of the current collection circuit are electrically connected with the output end of the current converter circuit, the current acquisition electricity
Road is used to acquire the electric current of the battery pack output；The current converter circuit includes:
Conversion element, the electric current to be detected for exporting the battery pack are converted into voltage to be detected；
First order amplifying circuit, the first order amplifying circuit are differential amplifier circuit, and the first order amplifying circuit includes two
A differential input end and output end, described two differential input ends connect with two voltage output ends of the conversion element respectively
It connects, for inputting the voltage to be detected of the conversion element output；
Second level amplifying circuit, including n amplification channel, input terminal and with the one-to-one n output end of n amplification channel；
The input terminal of the second level amplifying circuit is electrically connected with the output end of the first order amplifying circuit, and n amplification channel is used for
The signal that the input terminal of the second level amplifying circuit is inputted amplifies and exports respectively from corresponding output end, puts described in n
The corresponding sample range in channel greatly is different；Wherein, the corresponding sample range of the amplification channel is the second level amplifying circuit
When working in linear region, the range of the amplification channel output signal value, n is greater than 1 positive integer；
The current collection circuit includes n input terminal, n output of the n input terminal and the second level amplifying circuit
End corresponds electrical connection.
2. battery pack according to claim 1, it is characterised in that: the conversion element use first resistor, described first
Resistance and the battery pack are connected in series,；Two differential input ends of the first order amplifying circuit are electric with described first respectively
The both ends of resistance connect.
3. battery pack according to claim 2, it is characterised in that: the first order amplifying circuit includes the first operation amplifier
Device, second resistance, 3rd resistor, the 4th resistance and the 5th resistance；
The reverse input end and positive input of first operational amplifier pass through the second resistance and the third respectively
Resistance is electrically connected with the both ends of the first resistor；The reverse input end is put by the 4th resistance with first operation
The output end electrical connection of big device；The positive input by the 5th resistance eutral grounding, first operational amplifier it is defeated
Outlet is connect with the input terminal of the second level amplifying circuit.
4. battery pack according to claim 3, it is characterised in that: the reverse input end of first operational amplifier and institute
It states and is electrically connected first capacitor between the output end of the first operational amplifier.
5. battery pack according to claim 1, it is characterised in that: the second level amplifying circuit includes n the second operations
Amplifier, n the 6th resistance and n the 7th resistance；
The reverse input end of k-th of second operational amplifier passes through the 6th resistance of kth and the first order amplifying circuit
Output end electrical connection, is electrically connected k-th of the 7th resistance between the reverse input end and output end of k-th of second operational amplifier；
The positive input of the second operational amplifier is used for input reference voltage；
7th resistance of each second operational amplifier electrical connection and the ratio of the 6th resistance are different；
The reference voltage of the positive input input of each second operational amplifier is sequentially increased or is sequentially reduced；
Wherein k is the integer for being less than or equal to n more than or equal to 1.
6. battery pack according to claim 5, it is characterised in that: the second operational amplifier further includes that the second operation is put
Big first power input of device and the second source input terminal of second operational amplifier, a second operational amplifier of n
The first power supply (+Vcc) input terminal is for inputting the first supply voltage；Second electricity of first second operational amplifier
Source input terminal is for inputting second source voltage (- Vcc), the second source input of remaining n-1 second operational amplifiers
End ground connection or input second source voltage (- Vcc).
7. battery pack according to claim 5 or 6, the second level amplifying circuit further includes n the 8th resistance and n the
Nine resistance；
The positive input of k-th of second operational amplifier is connect by k-th of the 8th resistance with reference power source (Vr), and
Pass through k-th of the 9th resistance eutral groundings；
8th resistance of each second operational amplifier electrical connection and the resistance value of the 9th resistance are different.
8. battery pack according to claim 17, it is characterised in that: the battery pack further includes multiplexer；
The multiplexer includes n paths input terminal and a channel output end, and the n paths of the multiplexer are defeated
Enter end to be electrically connected with n output end of second level amplifying circuit one-to-one correspondence；The channel output end of the multiplexer
It is electrically connected with the input terminal of the current collection circuit.
9. a kind of electric current detecting method for the battery pack as described in claim 1-8 any one, the current detecting side
Method is executed by the current collection circuit of the battery management system, and the electric current detecting method includes:
The signal for sampling the n amplification channel output of the second level amplifying circuit one by one according to sequence from low to high, obtains n
The sampled value of a amplification channel；
Judge the sampled value of each amplification channel whether in the corresponding sample range of the amplification channel；
If so, using the sampled value of the amplification channel as this current sampling data.
10. a kind of electric tool combination, the battery pack including electric tool and as described in claim 1 to 8 any one, institute
Stating battery pack can mount to the electric tool to provide electric energy for the electric tool, and the electric tool includes:
Shell；
Attachment, for realizing the function of the electric tool；
Output shaft supports the attachment；
Motor is contained in the shell, and the output shaft is driven to rotate for output driving power；The motor is operationally
It is connected to the output shaft；
Battery pack engaging portion, for connecting the battery pack.
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| CN201711446269 | 2017-12-27 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115458818A (en) * | 2022-08-25 | 2022-12-09 | 圣邦微电子（北京）股份有限公司 | Current sampling circuit suitable for various types of battery packs |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101261290A (en) * | 2008-04-25 | 2008-09-10 | 奇瑞汽车股份有限公司 | Battery voltage supervisory circuit |
| CN101699307A (en) * | 2009-10-23 | 2010-04-28 | 广州蓝奇电子实业有限公司 | Modularized powered cell detection device |
| CN203630214U (en) * | 2013-12-10 | 2014-06-04 | 青岛伏科太阳能有限公司 | Current detecting circuit |
| CN203643497U (en) * | 2013-12-24 | 2014-06-11 | 青岛伏科太阳能有限公司 | Current detection circuit of photovoltaic system |
| CN104897953A (en) * | 2015-01-30 | 2015-09-09 | 中天储能科技有限公司 | Accurate lithium battery BMS system charging and discharging current sampling and calculation circuit and control method |
| CN105044607A (en) * | 2015-07-01 | 2015-11-11 | 中国电力科学研究院 | Battery module multichannel synchronous detection device |
| CN106058860A (en) * | 2016-07-07 | 2016-10-26 | 广东电网有限责任公司电力科学研究院 | Full-wave voltage integrated measurement apparatus suitable for transformer stations with multiple voltage grades |
-
2018
- 2018-12-25 CN CN201811589973.8A patent/CN109980304B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101261290A (en) * | 2008-04-25 | 2008-09-10 | 奇瑞汽车股份有限公司 | Battery voltage supervisory circuit |
| CN101699307A (en) * | 2009-10-23 | 2010-04-28 | 广州蓝奇电子实业有限公司 | Modularized powered cell detection device |
| CN203630214U (en) * | 2013-12-10 | 2014-06-04 | 青岛伏科太阳能有限公司 | Current detecting circuit |
| CN203643497U (en) * | 2013-12-24 | 2014-06-11 | 青岛伏科太阳能有限公司 | Current detection circuit of photovoltaic system |
| CN104897953A (en) * | 2015-01-30 | 2015-09-09 | 中天储能科技有限公司 | Accurate lithium battery BMS system charging and discharging current sampling and calculation circuit and control method |
| CN105044607A (en) * | 2015-07-01 | 2015-11-11 | 中国电力科学研究院 | Battery module multichannel synchronous detection device |
| CN106058860A (en) * | 2016-07-07 | 2016-10-26 | 广东电网有限责任公司电力科学研究院 | Full-wave voltage integrated measurement apparatus suitable for transformer stations with multiple voltage grades |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115458818A (en) * | 2022-08-25 | 2022-12-09 | 圣邦微电子（北京）股份有限公司 | Current sampling circuit suitable for various types of battery packs |
| CN115458818B (en) * | 2022-08-25 | 2024-05-14 | 圣邦微电子（北京）股份有限公司 | Current sampling circuit suitable for multiple types of battery packs |
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