CN111509318A - Power management system of battery and battery power supply system - Google Patents

Power management system of battery and battery power supply system Download PDF

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Publication number
CN111509318A
CN111509318A CN202010451853.2A CN202010451853A CN111509318A CN 111509318 A CN111509318 A CN 111509318A CN 202010451853 A CN202010451853 A CN 202010451853A CN 111509318 A CN111509318 A CN 111509318A
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CN
China
Prior art keywords
battery
electrically connected
resistor
power
mcu
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Pending
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CN202010451853.2A
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Chinese (zh)
Inventor
郭爱成
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Zhejiang Ken Power Tools Co ltd
Ken Holding Co ltd
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Zhejiang Ken Power Tools Co ltd
Ken Holding Co ltd
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Priority to CN202010451853.2A priority Critical patent/CN111509318A/en
Publication of CN111509318A publication Critical patent/CN111509318A/en
Pending legal-status Critical Current

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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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • G01R19/2503—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques for measuring voltage only, e.g. digital volt meters (DVM's)
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0031—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using battery or load disconnect circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0036—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using connection detecting circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with monitoring or indicating devices or circuits
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention discloses a power management system of a battery and a battery power supply system, wherein the power management system comprises a mechanical switch, an MCU (microprogrammed control unit) and a first battery control module; when the mechanical switch is closed, the power utilization terminal is started, and the battery is electrically connected with the first battery control module; the MCU performs starting control or protective shutdown on the power utilization terminal; the first battery control module comprises a first electronic switch circuit, a second electronic switch circuit and a first resistor; when the power utilization terminal is protected and shut down for a first preset time, and the MCU detects that the mechanical switch is still closed, the MCU controls the first output pin to output an effective level, so that the second electronic switch circuit is switched on, the first electronic switch circuit is switched off, and only the first resistor in the system is switched on. When the battery is in protective shutdown and the mechanical switch is not disconnected, the MCU outputs an effective level to turn off the power supplies of other circuits, so that the power consumption of a system is ignored when the mechanical switch is closed, and the battery is prevented from being discharged and damaged.

Description

Power management system of battery and battery power supply system
Technical Field
The present invention relates to the field of battery power supply circuits, and in particular, to a battery power management system and a battery power supply system.
Background
The battery-powered electric tool has a part of power supply mechanical switches with L ock on (the power supply mechanical switches are in a locking state even if the hand releases the switches after the switches are closed), the power supply mechanical switches can be kept closed during the operation of the tool, the operation is convenient, after battery over-temperature protection, battery over-current protection or battery under-voltage protection occurs, although the electric tool stops working under the intervention of a protection circuit, the switch is closed all the time and is not actively disconnected due to the L ock on switch structure, circuits such as a DC/DC (direct current/direct current) conversion circuit, an MCU (micro control unit) program operation, a battery voltage (analog/digital) sampling circuit and the like are working at the moment, the current loss of more than 10mA (milliampere) is counted, if the battery still has the capacity of 500mAh (milliampere hour), the battery is emptied in 50 hours, and the battery is discharged again, so that the battery voltage is reduced to be below the safe voltage of 2.5V, and irreversible damage is caused to the battery.
Disclosure of Invention
The invention aims to overcome the defects that a battery is possibly emptied and is irreversibly damaged in the prior art, and provides a power management system of the battery and a battery power supply system.
The invention solves the technical problems through the following technical scheme:
the invention provides a power management system of a battery, which is used for controlling the power supply of an electric terminal powered by the battery, and comprises a mechanical switch, an MCU (microprogrammed control unit) and a first battery control module;
one end of the mechanical switch is electrically connected with a battery, and the other end of the mechanical switch is electrically connected with the power utilization terminal and the first battery control module; when the mechanical switch is closed, the power utilization terminal is started, and the battery is electrically connected with the first battery control module;
the first battery control module is electrically connected with a power pin and a first output pin of the MCU; the MCU is electrically connected with the power utilization terminal and is used for starting, controlling or protecting and shutting down the power utilization terminal;
the first battery control module comprises a first electronic switch circuit, a second electronic switch circuit and a first resistor, wherein the input end of the first electronic switch circuit and one end of the first resistor are electrically connected with the other end of the mechanical switch, the other end of the first resistor is grounded, and the output end of the first electronic switch circuit is electrically connected with a power pin of the MCU; the second electronic switch circuit is electrically connected with a first output pin of the MCU, and the second electronic switch circuit is electrically connected with the first electronic switch circuit;
when the power utilization terminal is protected and shut down for a first preset time and the MCU detects that the mechanical switch is still in a closed state, the MCU controls the first output pin to output an effective level to enable the second electronic switch circuit to be switched on, and the control end of the second electronic switch circuit outputs a control signal to enable the first electronic switch circuit to be switched off, so that the power management system is only switched on by the first resistor.
Preferably, the first electronic switch circuit includes a voltage reference chip, a first triode, a second triode, a first diode, a second diode, a first capacitor, a second resistor, a third resistor, a fourth resistor and a fifth resistor;
the other end of the mechanical switch is electrically connected with the negative electrode of the first diode, the positive electrode of the second diode and the emitting electrode of the first triode, the positive electrode of the first diode is electrically connected with the base electrode of the second triode, the negative electrode of the second diode is electrically connected with one end of the second resistor, the collector electrode of the first triode and one end of the fifth resistor are electrically connected with the power pin of the MCU, the base electrode of the first triode is electrically connected with one end of the fourth resistor, and the other end of the fourth resistor is electrically connected with the cathode of the voltage reference chip;
the emitter of the second triode is electrically connected with the other end of the second resistor and the anode of the first capacitor, the collector of the second triode is electrically connected with the cathode of the first capacitor, one end of the third resistor, the other end of the fifth resistor and the reference voltage end of the voltage reference chip and is electrically connected with the control end of the second switch circuit, and the anode of the voltage reference chip is grounded.
Preferably, the second electronic switching circuit comprises a third triode;
the base electrode of the third triode is electrically connected with the first output pin of the MCU, the emitting electrode of the third triode is grounded, and the collecting electrode of the third triode is used as the control end of the second electronic switch circuit and is electrically connected with the first electronic switch circuit.
Preferably, the power management system of the battery further includes a second battery control module, where the second battery control module is electrically connected to the battery, the first input pin of the MCU, the second output pin of the MCU, the power pin of the MCU, and a power-consuming component in the power-consuming terminal that needs to be turned off in a delayed manner;
when the mechanical switch is switched off, the second battery control module continues to supply power to the MCU and the power utilization component needing to be turned off in a delayed mode through the battery, the first input pin outputs an effective level to the MCU, the MCU starts a braking action of the power utilization terminal, and after a second preset time is prolonged, the MCU outputs an effective level to the second output pin, so that the second battery control module stops supplying power.
Preferably, the second battery control module includes a fourth triode, a fifth triode, a sixth triode, a third diode, a sixth resistor and a seventh resistor;
an emitting electrode of the fourth triode is electrically connected with the positive electrode of the battery, a base electrode of the fourth triode is electrically connected with one end of the sixth resistor, the other end of the sixth resistor is electrically connected with a collector electrode of the fifth triode, a base electrode of the fifth triode is electrically connected with the second output pin of the MCU, and an emitting electrode of the fifth triode is grounded;
a collector electrode of the fourth triode is electrically connected with a cathode of the third diode and is electrically connected with a power pin of the MCU and the power utilization part needing to be turned off in a delayed manner; the positive electrode of the third diode is electrically connected with the base electrode of the sixth triode, the collector electrode of the first triode in the first battery control module and one end of the third resistor, the collector electrode of the sixth triode is electrically connected with one end of the seventh resistor, the other end of the seventh resistor is electrically connected with a power supply, and the emitter electrode of the sixth triode is grounded.
Preferably, the resistance value of the first resistor is 500k ohm-5M ohm.
Preferably, the power management system of the battery further comprises a battery voltage detection circuit, a current sampling amplification circuit and a battery temperature acquisition circuit, wherein the MCU is electrically connected with the battery voltage detection circuit, the current sampling amplification circuit and the battery temperature acquisition circuit respectively, so as to realize under-voltage battery shutdown, over-current battery shutdown and over-temperature battery shutdown.
Preferably, a DC/DC voltage reduction circuit is further disposed between the second battery control module and the power pin of the MCU.
The invention also provides a battery power supply system, which comprises a battery and the power management system of the battery, wherein the battery is electrically connected with the power management system and the power utilization terminal, and the power is supplied to the power utilization terminal under the control of the power management system.
On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.
The positive progress effects of the invention are as follows: according to the invention, by adding the electronic switch circuit, when the mechanical switch is not disconnected after the battery is protected and shut down for a period of time, the MCU outputs an effective level to turn off the power supplies of all circuits in the system, so that only one large-resistance resistor in the system is switched on and only uA (microampere) level current exists, the power consumption of the system is neglected when the mechanical switch is in a closed state, the battery can be prevented from being emptied to cause damage, and the safety of the battery is effectively protected.
Drawings
Fig. 1 is a schematic circuit structure diagram of a power management system according to embodiment 1 of the present invention.
Fig. 2 is a schematic circuit structure diagram of a first switch circuit of a power management system according to embodiment 2 of the present invention.
Fig. 3 is a schematic circuit structure diagram of a second switch circuit of the power management system according to embodiment 2 of the present invention.
Fig. 4 is a schematic circuit structure diagram of a power management system according to embodiment 3 of the present invention.
Fig. 5 is a schematic circuit structure diagram of a power management system according to embodiment 4 of the present invention.
Fig. 6 is a diagram of the voltage variation of the collector and emitter of the first transistor of the power management system in embodiment 4 of the present invention when the switch is turned off.
Fig. 7 is a schematic circuit structure diagram of a power management system according to embodiment 5 of the present invention.
Fig. 8 is a schematic circuit structure diagram of a battery power supply system according to embodiment 6 of the present invention.
Detailed Description
The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.
Example 1
The embodiment provides a power management system of a battery, which is used for performing power supply control on an electric terminal powered by the battery. As shown in fig. 1, the power management system of the battery includes a mechanical switch 1, a first battery control module 2, and an MCU 3.
One end of the mechanical switch 1 is electrically connected with the battery, and the other end of the mechanical switch 1 is electrically connected with the power utilization terminal and the first battery control module 2. When the mechanical switch 1 is closed, the electric terminal is activated and electrically connects the battery to the first battery control module 2.
The first battery control module 2 is electrically connected with a power supply pin and a first output pin of the MCU 3; the MCU3 is electrically connected with the power utilization terminal and is used for carrying out start control or protection shutdown on the power utilization terminal. The battery is generally provided with battery under-voltage protection, battery overcurrent protection and battery over-temperature protection, and when the battery has under-voltage, overcurrent and over-temperature conditions, the work of the power utilization terminal needs to be stopped so as to protect the battery.
The first battery control module 2 comprises a first electronic switch circuit 21, a second electronic switch circuit 22 and a first resistor R1, wherein the input end of the first electronic switch circuit 21 and one end of a first resistor R1 are electrically connected with the other end of the mechanical switch 1, the other end of the first resistor R1 is grounded, and the output end of the first electronic switch circuit 21 is electrically connected with a power supply pin of the MCU 3; the second electronic switch circuit 22 is electrically connected with a first output pin of the MCU3, and the second electronic switch circuit 22 is electrically connected with the first electronic switch circuit 21 through a control end;
when the power utilization terminal is protected and shut down for a first preset duration (for example, 15 seconds), and the MCU3 detects that the mechanical switch 1 is still in the closed state, the MCU3 controls the first output pin to output an active level, so that the second electronic switch circuit 22 is turned on, the second electronic switch circuit 22 outputs a control signal through the control terminal to turn off the first electronic switch circuit 21, and at this time, the power pin of the MCU3 is also powered off, so that the MCU3 stops working due to the absence of a control power supply (commonly referred to as suicide), and only the first resistor R1 in the whole power management system is turned on.
The resistance of the first resistor R1 is large enough, typically 500K (thousand) ohm to 5M (million) ohm, for example, 3M ohm, at this time, even if the battery is in a 20V full state, the current consumption is only 6.7uA, assuming that the battery capacity is still 500mAh and the voltage is 18V, the first resistor R1 calculates the discharge current of 6uA (actually, as the battery voltage decreases, the discharge current of the first resistor R1 decreases, the discharge time is longer), 83333 hours (9.5 years) is needed to empty the battery, even if the battery is still 100mAh, the battery needs 1.9 years to empty, so the discharge is negligible and will not damage the battery.
This embodiment is through increasing second electronic switch circuit, after battery protection shut down takes place a period, when detecting that mechanical switch still does not break off, MCU output effective level, the power of all circuits in the turn-off system, only have a big resistance to switch on in making the system, only have uA level electric current, can guarantee that mechanical switch is in the power consumptive neglect of system under the closed condition, the battery can not be emptied and lead to the damage, has protected battery safety effectively.
Example 2
In this embodiment, the first electronic switch circuit 21 and the second electronic switch circuit 22 are implemented based on embodiment 1.
As shown in fig. 2, the first electronic switch circuit 21 includes a voltage reference chip Z1, a first transistor Q1, a second transistor Q2, a first diode D1, a second diode D2, a first capacitor C1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5.
The other end of the mechanical switch 1 is electrically connected with the cathode of a first diode D1, the anode of a second diode D2 and the emitter of a first triode Q1, the anode of the first diode D1 is electrically connected with the base of a second triode Q2, the cathode of a second diode D2 is electrically connected with one end of a second resistor R2, the collector of the first triode Q1 and one end of a fifth resistor R5 are electrically connected with a power pin of the MCU3, the base of the first triode Q1 is electrically connected with one end of a fourth resistor R4, and the other end of the fourth resistor R4 is electrically connected with the cathode of the voltage reference chip Z1. The fourth resistor R4 is a current limiting resistor at the base of the first transistor Q1 to prevent the transistor from being burned out.
An emitter of the second triode Q2 is electrically connected with the other end of the second resistor R2 and the anode of the first capacitor C1, a collector of the second triode Q2 is electrically connected with the cathode of the first capacitor C1, one end of the third resistor R3, the other end of the fifth resistor R4 and the reference voltage terminal REF of the voltage reference chip Z1, and is electrically connected with the control terminal of the second electronic switch circuit 22, and the anode of the voltage reference chip Z1 is grounded.
When the mechanical switch 1 is closed, the contacts I and II, III and IV of the mechanical switch 1 are respectively closed, the contacts II and IV are connected with wires outside the mechanical switch 1, the contact III of the mechanical switch 1 is led to the first electronic switch circuit 21 in the first battery control module 2, and the battery voltage is charged to the first capacitor C1 through the second diode D2 — > the second resistor R2 — > the first capacitor C1 — > the third resistor R3 — > GND (ground). Since the first capacitor C1 has no charge at the beginning, the charging moment of the first capacitor C1 is equivalent to an inter-electrode short circuit of the first capacitor C1, and the voltage at the reference voltage terminal REF of the voltage reference chip Z1 is zero.
The first transistor Q1 is turned on if the anode and cathode of the voltage reference chip Z1 must be on, and the anode and cathode of the voltage reference chip Z1 must be on if the reference voltage terminal REF voltage of the voltage reference chip Z1 must be 2.5V, and when the reference voltage terminal REF voltage is <2.5V, the anode and cathode of the voltage reference chip Z1 will be immediately turned off, and the first transistor Q1 will be turned off.
Suppose the battery voltage is VbatWhen the second resistor R2 is 200K and the third resistor R3 is 100K, the voltage V at the reference voltage terminal REF of the voltage reference chip Z1 is Vref>The condition 2.5V is: (V)batPressure drop 0.6V) R3/(R2+ R3) of D2>2.5V, i.e. (V)bat-0.6V)/3>2.5V, i.e. Vbat>8.1V, i.e. when the battery voltage V isbat>When 8.1V, the voltage reference chip Z1 is turned on at the power-on instant of the mechanical switch 1, so that the first transistor Q1 is turned on, and after the first transistor Q1 is turned on, the power pin of the MCU3 connected to the collector of the first transistor Q1 is powered on, and the MCU3 starts to operate. At this time, the voltage of the reference voltage terminal REF of the voltage reference chip Z1 is stabilized above 2.5V by the voltage division of the fifth resistor R5 and the third resistor R3, so that the conduction of the first transistor Q1 is locked. In the above process, the charging current is reduced to zero due to the continuous charging of the first capacitor C1, and the first capacitor C1 is full of charge.
As shown in fig. 3, the second electronic switching circuit 22 includes a third transistor Q3. The base of the third triode Q3 is electrically connected with the first output pin of the MCU3, the emitter of the third triode Q3 is grounded, and the collector of the third triode Q3 is electrically connected with the first electronic switch circuit 21 as the control terminal of the second electronic switch circuit 22.
When the controller MCU3 detects the protection of battery under-voltage, battery over-current, battery over-temperature, etc., the MCU3 will brake the motor, which can prevent the battery from discharging with large current, but at this time, there are also the loss of DC/DC conversion circuit, current sampling and amplifying circuit, battery voltage AD conversion circuit, MCU peripheral circuit, etc., and MCU program operation, which will have the consumption of about ten or more mA in total, if the user does not turn off the switch, this loss will exist all the time. If the battery has 500mAh of capacity left, after 50 hours, the battery will be emptied and the battery will continue to discharge, the voltage of the lithium battery cells will drop to a safe voltage below 2.5V, and irreversible damage to the battery will occur.
To avoid this, a second switch circuit including a third transistor Q3 is added, and after a first predetermined time (e.g., 15 seconds) has elapsed after the protection shutdown, the MCU3 detects that the mechanical switch 1 has not been turned off, and then the MCU3 sets the first output pin high, the third transistor Q3 is turned on, the voltage reference terminal REF of the transient voltage reference chip Z1 is pulled to GND, the voltage reference chip Z1 is turned off, and the first transistor Q1 is turned off. At this time, although the emitter of the first transistor Q1 is connected to the battery through the mechanical switch 1, at this time, the first capacitor C1 is in a full charge state, which is equivalent to an open circuit state, so that even if the first output pin of the MCU3 is in a low level state or a high impedance state at this time, the voltage reference chip Z1 is not turned on, so that the first transistor Q1 is not turned on, the first electronic switch circuit 21 is turned off, the power supply pin of the MCU3 connected to the collector of the first transistor Q1 is turned off, so that the MCU3 loses control power supply and stops working, and only the first resistor R1 in the power management system is turned on. That is, only the first resistor R1 is in a power consumption state in the whole system, and the resistance value of the first resistor R1 takes a typical value of 3 mega ohms, at this time, even if the battery is in a full power state of 20V, the current consumption is only 6.7 uA. Assuming that the battery capacity is still 500mAh and the voltage is 18V, the first resistor R1 is calculated as a discharge current of 6uA (as the battery voltage decreases, the discharge current of the first resistor R1 also decreases), 83333 hours (9.5 years) are required for emptying the battery, and even if the battery only has 100mAh remaining, 1.9 years are required for emptying, so the discharge is negligible. Of course, the resistor R1 cannot be eliminated or too large because it is necessary for the first capacitor C1 to discharge, the resistor is too large, the second transistor Q2 is in a weak conducting state, the first capacitor C1 discharges very slowly, and if the mechanical switch 1 is turned off and on for a too short time interval, the voltage reference chip Z1 cannot be turned on again, i.e., the first transistor Q1 cannot be powered on smoothly.
When the system is powered up again, the mechanical switch 1 needs to be turned off and then turned on, after the mechanical switch 1 is turned off, the anode of the first capacitor C1, the emitter of the second triode Q2, the base of the second triode Q2, the first diode D1, the first resistor R1 and GND form a loop to enable the second triode Q2 to be turned on, so that the anode and the cathode of the first capacitor C1 are in short circuit, and the charge of the first capacitor C1 is neutralized and released; when the mechanical switch 1 is turned on again, the first capacitor C1 is charged again, and the voltage reference chip Z1 is turned on, so that the first transistor Q1 is turned on. Note that the first output pin of MCU3 normally needs to be in either a low state or a high state.
This embodiment is through increasing the second electronic switch circuit that contains a triode, after battery protection shut down takes place a period, when detecting that mechanical switch still does not break off, MCU output active level, switch on the triode in the second electronic switch circuit, output control signal makes first electronic switch circuit end, the power of all circuits in the shutoff system, only there is a big resistance resistor switch-on in making the system, only uA level electric current, can guarantee that mechanical switch is in the power consumptive neglect of system under the closed state, the battery can not be emptied and lead to the damage, battery safety has been protected effectively.
Example 3
This example is a further modification of example 2. As shown in fig. 4, the power management system of the battery of this embodiment further includes a second battery control module 4, where the second battery control module 4 is electrically connected to the battery, the first input pin, the second output pin, the power pin of the MCU3, and an electric component in the electric terminal that needs to be turned off in a delayed manner.
The second battery control module 4 is a power-on circuit without passing through the mechanical switch 1, and is used for ensuring that the power control system of the battery can supply power for a period of time after the mechanical switch 1 is turned off. When the mechanical switch 1 is disconnected, the second battery control module 4 continues to supply power to the MCU3 and power utilization components needing to be turned off in a delayed manner in the power utilization terminal through the directly connected batteries, the power utilization components needing to be turned off in a delayed manner refer to some electric tools, the motor is required to be capable of electronically braking and stopping after the mechanical switch 1 is disconnected, at this time, the MCU3 is required to continue to run in a powered manner, otherwise, the motor slides, and the personnel or property can be damaged in an emergency, because working heads driven by the motor in the tools can be dangerous components such as a cutter head, a grinding wheel, scissors and a drill bit; some electric tools have an auxiliary lighting function, and a user can keep the lighting lamp on for a certain time after the mechanical switch is turned off so as to conveniently work in a dark place; some tools which are frequently switched, such as gun drills, need to keep a control circuit at a stable control voltage, so that impact caused by power-on-power-off-power-on of a system is avoided, and the reliability of components is improved. Therefore, the power utilization part needing to be turned off in a delayed mode cannot be powered off instantly, and inertia buffering time is needed.
The second battery control module 4 inputs effective level to the first input pin of the MCU3, and the MCU3 starts the electronic braking action of the motor of the electric terminal, so that the safety can be effectively improved. After the first input pin of the MCU3 inputs the active level, a second preset time (for example, 15 seconds) is extended, the MCU3 controls the second output pin to output the active level, so that the second battery control module 4 stops supplying power, the MCU3 stops working, and meanwhile, the power consuming components of the power consuming terminal that need to be turned off in a delayed manner can be turned off safely after the second preset time, and all the power consuming components are turned off in the system, and no power consuming device is provided, so that the battery is not damaged.
In the embodiment, by adding the second battery control module, an inertia buffer time can be provided for the power utilization part needing to be turned off in a delayed manner in the power utilization terminal, power supply is continued for a period of time after the mechanical switch is turned off, and the power supply is turned off after the inertia buffer time is up, so that the safety of the system is further improved.
Example 4
This embodiment is implemented by embodying the second battery control module 4 on the basis of embodiment 3.
As shown in fig. 5, the second battery control module 4 includes a fourth transistor Q4, a fifth transistor Q5, a sixth transistor Q6, a third diode D2, a sixth resistor R6, and a seventh resistor R7. An emitting electrode of the fourth triode Q4 is electrically connected with a positive electrode of the battery, a base electrode of the fourth triode Q4 is electrically connected with one end of a sixth resistor R6, the other end of the sixth resistor R6 is electrically connected with a collector electrode of the fifth triode Q5, a base electrode of the fifth triode Q5 is electrically connected with a second output pin of the MCU3, and an emitting electrode of the fifth triode Q5 is grounded. A collector of the fourth triode Q4 is electrically connected with a cathode of the third diode D3, and is electrically connected with a power pin of the MCU3 and an electricity consuming component in the electricity consuming terminal that needs to be turned off in a delayed manner; the anode of the third diode D3 is electrically connected to the base of the sixth triode, the collector of the first triode Q1 in the first battery control module and one end of the third resistor R3, the collector of the sixth triode Q6 is electrically connected to one end of the seventh resistor R7, the other end of the seventh resistor R7 is electrically connected to the power supply, and the emitter of the sixth triode Q6 is grounded.
The emitting electrode of the fourth triode Q4 is directly connected with the positive electrode of the battery, when the mechanical switch 1 is closed, the first electronic switch circuit 21 is conducted, the MCU3 is powered on and operates, the second output pin of the MCU3 is set to be at a high level, the fifth triode Q5 is conducted, so that the fourth triode Q4 is conducted, even if the mechanical switch 1 is disconnected, the first triode Q1 is powered off, the fourth triode Q4 provides power from the battery, and the MCU3 continues to be powered on and operates.
At this time, due to the blocking of the third diode D3, the first transistor Q1 cannot obtain power from the power pin of the MCU3, and maintains the power-off state. Meanwhile, the voltage drop of the base electrode of the sixth triode Q6 connected with the collector electrode of the first triode Q1 is zero, the sixth triode Q6 is cut off, the collector electrode of the sixth triode Q6 is pulled high, and the first input pin of the MCU3 is also set high. After the MCU3 detects the level change of the first input pin, the mechanical switch 1 is judged to be switched off, and the braking action of the motor of the electric terminal is started immediately, so that the safety can be effectively improved. After the MCU3 delays the time for the second preset duration (for example, 15 seconds), and it is found that the mechanical switch 1 is not closed for the second time, the second output pin is set to a low level, so that the fifth transistor Q5 is turned off, the fourth transistor Q4 is also turned off, the second battery control module 4 is disconnected, and then the whole system is completely turned off without power consuming devices.
Fig. 6 shows the emitter and collector voltage variation curves of the first transistor Q1 after the mechanical switch 1 is turned off. The voltage at the input end (emitter) of the first triode Q1 has a falling curve, the slope of the curve is related to the resistance of the first resistor R1, the larger the resistance of the first resistor R1 is, the slower the falling is, that is, the slower the charge of the first capacitor C1 is released. It has been determined that if the first resistor R1 is 3 mega ohms, the first capacitor C1 can discharge substantially all of the charge at a battery voltage of 20V at full charge, at approximately 50mS, and the angle grinder switch has a time from opening to rapid secondary closing of at least 80mS, so the first capacitor C1 is sufficient to recover to the empty charge condition of the secondary power-up condition.
The collector voltage variation curve of the first transistor Q1 in fig. 6 shows that the mechanical switch 1 drops very steeply after being turned off, so the first input pin of the MCU3 immediately changes from low level to high level, and the MCU3 can immediately take a motor braking action accordingly, thereby improving safety.
In the embodiment, by adding the second battery control module, an inertia buffer time can be provided for the power utilization part needing to be turned off in a delayed manner in the power utilization terminal, power supply is continued for a period of time after the mechanical switch is turned off, and the power supply is turned off after the inertia buffer time is up, so that the safety of the system is further improved.
Example 5
This example was further completed based on examples 3 and 4.
As shown in fig. 7, the power management system of the battery further includes a battery voltage detection circuit 5, a current sampling amplification circuit 6, and a battery temperature acquisition circuit 7, and the MCU3 is electrically connected to the battery voltage detection circuit 5, the current sampling amplification circuit 6, and the battery temperature acquisition circuit 7, respectively, to acquire the voltage, the current, and the temperature of the battery, thereby realizing the under-voltage protection shutdown of the battery, the over-current protection shutdown of the battery, and the over-temperature protection shutdown of the battery.
A DC/DC voltage reduction circuit 8 is also provided between the second battery control module 4 and the power pin of the MCU3 to provide the MCU3 with a suitable power supply voltage.
The battery voltage detection circuit 5, the current sampling amplification circuit 6, the battery temperature acquisition circuit 7 and the DC/DC voltage reduction circuit 8 are mature circuits, and are not described in detail here.
Example 6
The present embodiment provides a battery power supply system, as shown in fig. 8, the battery power supply system includes the power management system of the battery, and the power consumption terminal described in embodiments 1 to 5, the battery is electrically connected to the power management system and the power consumption terminal, and the power is supplied to the power consumption terminal under the control of the power management system.
The battery power supply system of the embodiment is suitable for electric equipment with a locking mechanical switch, such as a battery-powered electric tool with a locking mechanical switch, such as an angle grinder, an electric circular saw, a pruner, and the like, and is not limited thereto, but also includes lighting equipment such as a flashlight and the like in daily use. Meanwhile, the electric tool is not only a brushless motor tool, but also a brush motor tool. The mechanical switch is separately locked and unlocked, and when the electric tool is developed, the mechanical switch without the lock is bound by a binding belt for test convenience to perform a discharge test, so the battery power supply system of the embodiment can also be applied to electric equipment without the mechanical switch with the lock in a debugging stage.
While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims (9)

1. A power management system of a battery is used for controlling the power supply of an electric terminal powered by the battery, and is characterized by comprising a mechanical switch, an MCU (microprogrammed control unit) and a first battery control module;
one end of the mechanical switch is electrically connected with a battery, and the other end of the mechanical switch is electrically connected with the power utilization terminal and the first battery control module; when the mechanical switch is closed, the power utilization terminal is started, and the battery is electrically connected with the first battery control module;
the first battery control module is electrically connected with a power pin and a first output pin of the MCU; the MCU is electrically connected with the power utilization terminal and is used for starting, controlling or protecting and shutting down the power utilization terminal;
the first battery control module comprises a first electronic switch circuit, a second electronic switch circuit and a first resistor, wherein the input end of the first electronic switch circuit and one end of the first resistor are electrically connected with the other end of the mechanical switch, the other end of the first resistor is grounded, and the output end of the first electronic switch circuit is electrically connected with a power pin of the MCU; the second electronic switch circuit is electrically connected with a first output pin of the MCU, and the second electronic switch circuit is electrically connected with the first electronic switch circuit;
when the power utilization terminal is protected and shut down for a first preset time and the MCU detects that the mechanical switch is still in a closed state, the MCU controls the first output pin to output an effective level to enable the second electronic switch circuit to be switched on, and the control end of the second electronic switch circuit outputs a control signal to enable the first electronic switch circuit to be switched off, so that the power management system is only switched on by the first resistor.
2. The power management system of claim 1, wherein the first electronic switching circuit comprises a voltage reference chip, a first transistor, a second transistor, a first diode, a second diode, a first capacitor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor;
the other end of the mechanical switch is electrically connected with the negative electrode of the first diode, the positive electrode of the second diode and the emitting electrode of the first triode, the positive electrode of the first diode is electrically connected with the base electrode of the second triode, the negative electrode of the second diode is electrically connected with one end of the second resistor, the collector electrode of the first triode and one end of the fifth resistor are electrically connected with the power pin of the MCU, the base electrode of the first triode is electrically connected with one end of the fourth resistor, and the other end of the fourth resistor is electrically connected with the cathode of the voltage reference chip;
the emitter of the second triode is electrically connected with the other end of the second resistor and the anode of the first capacitor, the collector of the second triode is electrically connected with the cathode of the first capacitor, one end of the third resistor, the other end of the fifth resistor and the reference voltage end of the voltage reference chip and is electrically connected with the control end of the second switch circuit, and the anode of the voltage reference chip is grounded.
3. The power management system of claim 1, wherein said second electronic switching circuit comprises a third transistor;
the base electrode of the third triode is electrically connected with the first output pin of the MCU, the emitting electrode of the third triode is grounded, and the collecting electrode of the third triode is used as the control end of the second electronic switch circuit and is electrically connected with the first electronic switch circuit.
4. The power management system of the battery according to claim 2, further comprising a second battery control module electrically connected to the battery, the first input pin of the MCU, the second output pin of the MCU, the power pin of the MCU, and the power-consuming components of the power-consuming terminal that need to be turned off in a delayed manner;
when the mechanical switch is switched off, the second battery control module continues to supply power to the MCU and the power utilization component needing to be turned off in a delayed mode through the battery, the first input pin outputs an effective level to the MCU, the MCU starts a braking action of the power utilization terminal, and after a second preset time is prolonged, the MCU outputs an effective level to the second output pin, so that the second battery control module stops supplying power.
5. The power management system of claim 4, wherein the second battery control module comprises a fourth transistor, a fifth transistor, a sixth transistor, a third diode, a sixth resistor, and a seventh resistor;
an emitting electrode of the fourth triode is electrically connected with the positive electrode of the battery, a base electrode of the fourth triode is electrically connected with one end of the sixth resistor, the other end of the sixth resistor is electrically connected with a collector electrode of the fifth triode, a base electrode of the fifth triode is electrically connected with the second output pin of the MCU, and an emitting electrode of the fifth triode is grounded;
a collector electrode of the fourth triode is electrically connected with a cathode of the third diode and is electrically connected with a power pin of the MCU and the power utilization part needing to be turned off in a delayed manner; the positive electrode of the third diode is electrically connected with the base electrode of the sixth triode, the collector electrode of the first triode in the first battery control module and one end of the third resistor, the collector electrode of the sixth triode is electrically connected with one end of the seventh resistor, the other end of the seventh resistor is electrically connected with a power supply, and the emitter electrode of the sixth triode is grounded.
6. The battery power management system of claim 2, wherein the first resistor has a resistance of 500k ohms to 5M ohms.
7. The power management system of claim 1, wherein the power management system further comprises a battery voltage detection circuit, a current sampling amplification circuit and a battery temperature acquisition circuit, and the MCU is electrically connected to the battery voltage detection circuit, the current sampling amplification circuit and the battery temperature acquisition circuit respectively to implement a battery under-voltage protection shutdown, a battery over-current protection shutdown and a battery over-temperature protection shutdown.
8. The power management system of claim 4, wherein a DC/DC voltage reduction circuit is further disposed between the second battery control module and the power pin of the MCU.
9. A battery power supply system, characterized in that the battery power supply system comprises a battery and a power management system of the battery according to any one of claims 1 to 8, the battery is electrically connected with the power management system and a power terminal, and the power terminal is powered under the control of the power management system.
CN202010451853.2A 2020-05-22 2020-05-22 Power management system of battery and battery power supply system Pending CN111509318A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113098097A (en) * 2021-04-12 2021-07-09 深圳市海和科技股份有限公司 Electrical equipment, power supply system and control method thereof
CN114236226A (en) * 2021-12-20 2022-03-25 上海瑞浦青创新能源有限公司 Voltage measurement circuit
WO2024051255A1 (en) * 2022-09-07 2024-03-14 海能达通信股份有限公司 Power failure protection circuit and electronic device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113098097A (en) * 2021-04-12 2021-07-09 深圳市海和科技股份有限公司 Electrical equipment, power supply system and control method thereof
CN114236226A (en) * 2021-12-20 2022-03-25 上海瑞浦青创新能源有限公司 Voltage measurement circuit
WO2024051255A1 (en) * 2022-09-07 2024-03-14 海能达通信股份有限公司 Power failure protection circuit and electronic device

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