CN203839985U - Cell discharge overcurrent protection circuit - Google Patents
Cell discharge overcurrent protection circuit Download PDFInfo
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- CN203839985U CN203839985U CN201320828682.6U CN201320828682U CN203839985U CN 203839985 U CN203839985 U CN 203839985U CN 201320828682 U CN201320828682 U CN 201320828682U CN 203839985 U CN203839985 U CN 203839985U
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Abstract
The utility model discloses a cell discharge overcurrent protection circuit. The overcurrent protection circuit comprises a discharge switch tube, a discharge control module used for detecting discharge current of a cell in real time and a time-delay module used for determining whether overcurrent timeout occurs by comparing time of overcurrent generation with the preset time-delay time. Whether overcurrent occurs is determined by comparing the detected discharge current with a preset threshold, if the overcurrent does not occur, the discharge switch tube is controlled to open; and if the overcurrent occurs, and the overcurrent timeout occurs, the discharge switch tube is locked in a turn-off state. Through enforcement of the technical scheme, when a load is connected with a cell, the transient current during cell discharge can be reduced, transient energy during cell discharge is effectively restricted, and safety of the cell is improved.
Description
Technical field
The utility model relates to battery protection field, relates in particular to a kind of current foldback circuit of battery discharge.
Background technology
Battery-powered electronic equipment, after repeatedly changing battery, mostly occur the phenomenon of battery pole piece contact blackout, thereby it is unreliable that electronic equipment is powered on.Its main cause is that the discharging current of battery is not reasonably controlled.For example, when changing battery to electronic equipment, the moment that battery pole piece contacts with the battery tray of electronic equipment produces large pulse current, and the sparking of battery pole piece contact produces high-temperature oxydation and causes battery pole piece contact blackout.The hand-hold electronic equipments using in some inflammable and explosive environment, for safety, need to be the energy limited of battery discharge in certain safety value.The Transient Currents of battery discharge is to the storage of battery and use and to have safe hidden danger, therefore, how reasonably the current limit of battery discharge in the limit value of safety, do not affect again normal use, be the important technological problems that battery protection need to solve.
At present, the overcurrent protection of existing battery discharge mainly in the following ways: at the idle state of battery, discharge switch pipe is often opened.In discharge process, the electric current that protective circuit detects battery discharge surpasses after the threshold value of design, and discharge switch pipe postpones certain hour and turn-offs, ends battery discharge.Within the time of turn-off delay, discharge switch pipe continues to open, and has large pulse current on discharge path.The shortcoming of this method is that battery safety in utilization contradicts the requirement of time of delay with the charging of capacity load.If delay time design is shorter; the load that contains large electric capacity requires turn-off delay time longer while powering on, if the time postponing is inadequate, and the electric capacity of the load electricity that also do not have enough time to be full of; battery protecting circuit is ended to have discharged with regard to producing current-limiting protection, and load can not normal power-up.If design time of delay is longer, met the charging requirement of large capacitive load, if but there is suddenly short circuit in the electric discharge port of battery, will produce large pulse current, there is the hidden danger of the accidents such as initiation fire or burn human body.Using such battery, often there is the phenomenon of battery pole piece contact oxidation blackout loose contact in equipment.
Utility model content
The technical problems to be solved in the utility model is; for prior art above-mentioned can not be by the current limit of battery discharge the defect in the limit value of safety; a kind of current foldback circuit of battery discharge is provided, can be well by the current limit of battery discharge in the limit value of safety.
The utility model solves the technical scheme that its technical problem adopts: construct a kind of current foldback circuit of battery discharge, comprise the discharge switch pipe being connected in battery discharge path, described current foldback circuit also comprises:
For detecting in real time the discharging current of battery, and judge whether to occur overcurrent by the discharging current relatively detecting with default threshold value, if without generation overcurrent, control described discharge switch pipe open-minded; If generation overcurrent, controls described discharge switch pipe and turn-offs, and, when overcurrent is overtime, described discharge switch pipe is locked in to the control of discharge module of off state;
Be connected in described control of discharge module, and for judging by relatively there is the time of overcurrent and default delay time the time delay module whether overcurrent overtime.
In the current foldback circuit of battery discharge described in the utility model, described control of discharge module comprises battery protection chip, sampling resistor, comparator, Current limited Control switching tube, wherein, the first end of described sampling resistor connects respectively negative pole and the ground of described battery, the second end of discharge switch pipe and the first input end of described comparator described in the second termination of described sampling resistor, the negative pole of the first termination discharge end mouth of described discharge switch pipe, the second input termination reference voltage of described comparator, the control end of Current limited Control switching tube described in the output termination of described comparator, the second end ground connection of described Current limited Control switching tube, the first end of described Current limited Control switching tube connects respectively the control end of described discharge switch pipe and the control of discharge end of described battery protection chip.
In the current foldback circuit of battery discharge described in the utility model, described control of discharge module comprises battery protection chip, sampling resistor, comparator, amplifier, Current limited Control switching tube, wherein, the first end of described sampling resistor connects respectively the first input end of the anodal and described amplifier of described battery, the second end of described sampling resistor connects respectively the second input of the anodal and described amplifier of electric discharge port, the first input end of comparator described in the output termination of described amplifier, the second input termination reference voltage of described comparator, the control end of Current limited Control switching tube described in the output termination of described comparator, the second end ground connection of described Current limited Control switching tube, the first end of described Current limited Control switching tube connects respectively the control end of described discharge switch pipe and the control of discharge end of described battery protection chip, the negative pole of the first termination discharge end mouth of described discharge switch pipe, the second end of described discharge switch pipe connects respectively negative pole and the ground of battery.
In the current foldback circuit of battery discharge described in the utility model; described control of discharge module also comprises current-limiting resistance; the first end of described current-limiting resistance is connected to the control of discharge end of described battery protection chip, and the second end of described current-limiting resistance connects the control end of described discharge switch pipe and the first end of described Current limited Control switching tube.
In the current foldback circuit of battery discharge described in the utility model, described time delay module comprises the first diode, the first switching tube, second switch pipe, the first electric capacity, the first resistance, the second resistance, the 3rd resistance and the 4th resistance, wherein, the voltage sample end of battery protection chip described in the first termination of described the first switching tube, the second end of the second end of described the first switching tube and second switch pipe is ground connection respectively, and the first end of the control end of described the first switching tube and described second switch pipe connects the negative pole of described electric discharge port by described the first resistance; The positive pole of described the first diode connects the negative pole of described electric discharge port; the negative pole of described the first diode connects the first end of described the first electric capacity and the control end of described second switch pipe by described the second resistance; the second end ground connection of described the first electric capacity; the negative pole of described electric discharge port also connects the voltage sample end of described battery protection chip by described the 3rd resistance, described the 4th resistance is connected between the negative pole and ground of described the first diode.
In the current foldback circuit of battery discharge described in the utility model, described control of discharge module comprises battery protection chip, sampling resistor, Current limited Control switching tube, the 5th resistance, the 6th resistance, the second electric capacity and the second diode, wherein, the first end of described sampling resistor connects respectively negative pole and the ground of described battery, the second end of described sampling resistor connects respectively the second end of described discharge switch pipe and the second end of described Current limited Control switching tube, the negative pole of the first termination discharge end mouth of described discharge switch pipe, the positive pole of the second diode described in the control termination of described discharge switch pipe, the negative pole of described the second diode connects the control of discharge end of described battery protection chip, described the 6th resistance is connected between the positive pole and negative pole of described the second diode, the voltage sample end of battery protection chip described in the first termination of described Current limited Control switching tube, the control of discharge end of battery protection chip described in the first termination of described the 5th resistance, the second end of described the 5th resistance connects respectively the control end of described Current limited Control switching tube and the first end of described the second electric capacity, the second end ground connection of described the second electric capacity.
In the current foldback circuit of battery discharge described in the utility model, described time delay module comprises the first diode, the second resistance, the 3rd resistance, the 4th resistance, the first electric capacity and second switch pipe, wherein, the positive pole of described the first diode connects the negative pole of described electric discharge port, the negative pole of described the first diode connects the first end of described the first electric capacity and the control end of described second switch pipe by described the second resistance, the second end ground connection of the second end of described the first electric capacity and described second switch pipe, the first end of described second switch pipe connects the control end of described Current limited Control switching tube, the negative pole of described electric discharge port also connects the voltage sample end of described battery protection chip by described the 3rd resistance, described the 4th resistance is connected between the negative pole and ground of described the first diode.
In the current foldback circuit of battery discharge described in the utility model; described control of discharge module also comprises the 3rd diode and the 7th resistance; wherein; the negative pole of described the 3rd diode connects the control end of described Current limited Control switching tube, and the positive pole of described the 3rd diode connects the negative pole of described electric discharge port by described the 7th resistance.
Implement the technical solution of the utility model, after load access battery, detect in real time discharging current, and judge whether to occur overcurrent, if without there is overcurrent, controlled discharge switching tube is open-minded; If generation overcurrent, controlled discharge switching tube turn-offs, and meanwhile, by relatively there is the time of overcurrent and default delay time, judges that whether overcurrent is overtime, if overtime, discharge switch pipe is locked in to off state.Like this, when there is overcurrent, if overcurrent is not overtime, during occurring at overcurrent, discharge switch pipe is worked to be interrupted the mode of opening, and while waiting overcurrent to finish, discharge switch pipe continues open-minded; If overtime,, in delay time, discharge switch pipe is worked to be interrupted the mode of opening, and after delay time finishes, discharge switch pipe will be locked in off state.Therefore, when battery charges to capacity load, not the disposable electricity that is full of, but the repeatedly accumulation of charging, therefore can reduce the transient current of battery discharge, effectively limited the discharge energy of battery, the fail safe that has improved battery.
Accompanying drawing explanation
Below in conjunction with drawings and Examples, the utility model is described in further detail, in accompanying drawing:
Fig. 1 is the logic diagram of the current foldback circuit embodiment mono-of the utility model battery discharge;
Fig. 2 be in Fig. 1 discharging current and discharge switch tubulose state respectively with the sequential chart of load time;
Fig. 3 is the circuit diagram of the current foldback circuit embodiment bis-of the utility model battery discharge;
Fig. 4 is the circuit diagram of the current foldback circuit embodiment tri-of the utility model battery discharge;
Fig. 5 is the circuit diagram of the current foldback circuit embodiment tetra-of the utility model battery discharge;
Fig. 6 is the flow chart of the over-current protection method embodiment mono-of the utility model battery discharge.
Embodiment
Fig. 1 is the logic diagram of the current foldback circuit embodiment mono-of the utility model battery discharge, the current foldback circuit of this battery discharge comprises discharge switch pipe (not shown), control of discharge module 10 and time delay module 20, wherein, discharge switch pipe is connected in battery discharge path, control of discharge module 10 is for detecting in real time the discharging current of battery, and judge whether to occur overcurrent by the discharging current that relatively detects and default threshold value, if without overcurrent occurs, control described discharge switch pipe open-minded; If generation overcurrent, controls described discharge switch pipe and turn-offs, and, when overcurrent is overtime, described discharge switch pipe is locked in to off state.Time delay module 20 is for judging that by relatively there is the time of overcurrent and default delay time whether overcurrent is overtime.
In conjunction with Fig. 2, after load access battery, start to detect the discharging current i of battery
dthereby, judge whether to occur overcurrent, whether surpass the threshold value i of electric current
r.If without there is overcurrent, controlled discharge switching tube is open-minded; If generation overcurrent, controlled discharge switching tube turn-offs, and meanwhile, by relatively there is the time of overcurrent and default delay time, judges that whether overcurrent is overtime, if overtime, discharge switch pipe is locked in to off state.For example,, if at t
1constantly there is overcurrent, at t
2overcurrent finishes constantly, and overcurrent is without overtime,, the time (t of overcurrent occurs that is
2-t
1time period) without surpassing delay time, during this electric discharge overcurrent in, control of discharge module 10 controlled discharge switching tubes are worked to be interrupted the mode of opening, and after electric discharge overcurrent finishes, controlled discharge switching tube continues open-minded.At this, it should be noted that, when controlled discharge switching tube moves, should consider response time t
0.
Again for example, if the electric discharge of battery at t
3constantly there is overcurrent, and at t
4overcurrent does not also finish constantly,, the time (t of overcurrent occurs that is
4-t
3time period) reach delay time t
d, at delay time t
din, control of discharge module 10 controlled discharge switching tubes are worked to be interrupted the mode of opening, and when delay time finishes, that is, and at t
4constantly, discharge switch pipe is locked in to off state.
Implement the technical scheme of this embodiment, after load access battery, when there is overcurrent, if overcurrent is not overtime, during occurring at overcurrent, discharge switch pipe is worked to be interrupted the mode of opening, and while waiting overcurrent to finish, discharge switch pipe continues open-minded; If overtime,, in delay time, discharge switch pipe is worked to be interrupted the mode of opening, and after delay time finishes, discharge switch pipe will be locked in off state.Therefore, when battery charges to capacity load, not the disposable electricity that is full of, but the repeatedly accumulation of charging, therefore can reduce the transient current of battery discharge, effectively limited the transient energy of the electric discharge of battery, the fail safe that has improved battery.
Fig. 3 is the circuit diagram of the current foldback circuit embodiment bis-of the utility model battery discharge, and battery comprises battery core B1, the B2 being in series, and the positive pole of battery core B1 is the positive pole of battery, and the negative pole of battery core B2 is the negative pole of battery, and, the minus earth of battery.The current foldback circuit of this battery discharge comprises discharge switch pipe, control of discharge module and time delay module.In addition, this battery is rechargeable battery, and this current foldback circuit also comprises charge switch pipe.And in this embodiment, discharge switch pipe is selected metal-oxide-semiconductor Q2, charge switch pipe is selected metal-oxide-semiconductor Q1.Certainly, if this battery can be non-rechargeable battery in other embodiments, now, can save charge switch pipe.Illustrate respectively control of discharge module and time delay module below.
In control of discharge module, it is the chip of S8232 that battery protection chip U1 can select model, and about each port of battery protection chip U1, wherein, DO is control of discharge end, for controlling metal-oxide-semiconductor Q2.CO is charging control end, for controlling metal-oxide-semiconductor Q1.ICT is timing capacitor link, and this timing capacitor is capacitor C 4, and adjustable the discharging and recharging of capacity that changes capacitor C 4 detected the response time.VM is voltage sample end, and the reference voltage of this port input voltage and its inner setting (being for example 0.3V) compares, and comparative result is controlled for the thresholding of electric current.VC, SENS are the battery core voltage detecting end of battery, and wherein, VC connects the positive pole of battery core B2 by resistance R 3, and SENS connects the positive pole of battery core B1 by resistance R 1.VCC is IC internal wiring feeder ear, and it connects the positive pole of battery core B1 by resistance R 2.In addition, VCC, VC, SENS end are respectively by capacitor C 2, C3, C1 ground connection, and these electric capacity play voltage stabilizing and filter action, can save in other embodiments.
When work; if state is normal,, without there is electric discharge overcurrent also without there is charging overcurrent, the control of discharge end (DO) of battery protection chip U1, charging control end (CO) be output HIGH voltage all; control metal-oxide-semiconductor Q1 and metal-oxide-semiconductor Q2 conducting, thereby form charging path or discharge path.In when electric discharge, if when battery core voltage surpasses threshold lower than discharge voltage thresholding or discharging current, control of discharge end (DO) output LOW voltage of battery protection chip U1 is controlled metal-oxide-semiconductor Q2 and turn-offed, battery is ended electric discharge.When charging, if battery core voltage surpasses charging voltage thresholding, the charging control end (CO) of battery protection chip U1 turn-offs output LOW voltage to control metal-oxide-semiconductor Q1, end the charging to battery.
In control of discharge module, the negative pole of the first termination battery core B2 of sampling resistor R4, the source electrode of the second termination metal-oxide-semiconductor Q2 of sampling resistor R4, the second end of sampling resistor R4 also connects the first input end (IN+) of comparator U2 by resistance R 10, the second input (IN-) of comparator U2 meets reference voltage Verf, the drain electrode of metal-oxide-semiconductor Q2 connects the drain electrode of metal-oxide-semiconductor Q1, the source electrode of metal-oxide-semiconductor Q1 meets the negative pole P-of electric discharge port, the grid of metal-oxide-semiconductor Q2 connects the control of discharge end (DO) of battery protection chip U1 by resistance R 6, the grid of metal-oxide-semiconductor Q1 connects the charging control end (CO) of battery protection chip U1.The grid of the output termination metal-oxide-semiconductor Q3 of comparator U2, the source ground of metal-oxide-semiconductor Q3, the drain electrode of metal-oxide-semiconductor Q3 connects the grid of metal-oxide-semiconductor Q2.In addition, between the second input (IN-) of comparator U2 and ground, be also connected with capacitor C 7, the power end of comparator U2 (VCC) connects the positive pole of battery core B1, and, between the power end of comparator U2 (VCC) and ground, be also connected with capacitor C 5.At this, it should be noted that, the reference voltage of comparator U2 can be provided by voltage stabilizing chip, also can be provided by other reference voltage source.In addition, capacitor C 3, C2, C1, C7, C5 play voltage stabilizing and filter action in this embodiment, and resistance R 10, R6 play metering function, and these electric capacity and resistance can save in other embodiments.
In time delay module; the source electrode of metal-oxide-semiconductor Q5 connects the voltage sample end (VM) of battery protection chip U1; the drain electrode of metal-oxide-semiconductor Q5 connects the drain electrode of metal-oxide-semiconductor Q4; the source electrode of the source electrode of metal-oxide-semiconductor Q4 and metal-oxide-semiconductor Q6 is ground connection respectively; the drain electrode of the grid of the grid of metal-oxide-semiconductor Q5, metal-oxide-semiconductor Q4 and metal-oxide-semiconductor Q6 is connected together, and by resistance R 7, receives the negative pole P-of electric discharge port.The positive pole of diode D1 connects the negative pole P-of electric discharge port; the negative pole of diode D1 connects the first end of capacitor C 6 and the grid of metal-oxide-semiconductor Q6 by resistance R 8; the second end ground connection of capacitor C 6, the negative pole P-of electric discharge port also connects the voltage sample end (VM) of battery protection chip U1 by resistance R 5.In addition, be also connected with resistance R 9 between the negative pole of diode D1 and ground, resistance R 9 provides discharge path for C6.And in this embodiment, metal-oxide-semiconductor Q4, Q5 are because all inverse parallel has diode, for preventing two-way admittance, so selected, metal-oxide-semiconductor Q4, Q5 are as above to be connected in series.If select, be not with the metal-oxide-semiconductor of anti-paralleled diode, can substitute metal-oxide-semiconductor Q4, the Q5 being in series with a metal-oxide-semiconductor.
The following describes the course of work of current foldback circuit of the battery discharge of this embodiment: when by after load access electric discharge port; charging control end (CO) and the control of discharge end (DO) of battery protection chip U1 are all exported high level, and metal-oxide-semiconductor Q1, Q2 are open-minded.If normal condition; during without generation electric discharge overcurrent; voltage on sampling resistor R4 is lower than the reference voltage of comparator U2; the output of comparator U2 (OUT) output low level; metal-oxide-semiconductor Q3 turn-offs; metal-oxide-semiconductor Q2 is drawn high open-mindedly because of its grid voltage by the high voltage of the control of discharge end (DO) of battery protection chip U1, now, the output voltage of battery battery core forms discharge path through electric discharge port, metal-oxide-semiconductor Q1, Q2.
When there is electric discharge overcurrent, voltage on sampling resistor R4 is greater than the reference voltage of comparator U2, the output of comparator U2 (OUT) output high level, and metal-oxide-semiconductor Q3 is open-minded, metal-oxide-semiconductor Q2 is dragged down and turn-offs by metal-oxide-semiconductor Q3 because of its grid voltage, and discharge path disconnects.When closing, metal-oxide-semiconductor Q2 has no progeny; voltage drop on sampling resistor R4; when this voltage is during lower than the reference voltage of comparator U2; comparator U2 is output low level again; metal-oxide-semiconductor Q3 turn-offs again; metal-oxide-semiconductor Q2 is drawn high open-mindedly because of its grid voltage by the high voltage of the control of discharge end (DO) of battery protection chip U1, discharge path is again open-minded.Like this, metal-oxide-semiconductor Q2 is operated in and is interrupted the state of opening.
In addition, metal-oxide-semiconductor Q2 blocking interval after battery discharge overcurrent, the voltage of the negative pole P-of electric discharge port is elevated, and it is open-minded that this voltage is controlled metal-oxide-semiconductor Q4, Q5 by resistance R 7, thereby voltage sample end (VM) ground connection of battery protection chip U1.Meanwhile, the high voltage of the negative pole P-of electric discharge port is by diode D1,6 chargings of 8 pairs of capacitor C of resistance R.Because metal-oxide-semiconductor Q2 during overcurrent is interrupted to turn-off, so, the charging of capacitor C 6 is repeatedly accumulated.
Along with the voltage rising of capacitor C 6, before reaching the turn-on threshold voltage of metal-oxide-semiconductor Q6, metal-oxide-semiconductor Q2 is operated in interruption off state.If the voltage of capacitor C 6 reaches the turn-on threshold voltage of metal-oxide-semiconductor Q6, metal-oxide-semiconductor Q6 is open-minded, metal-oxide-semiconductor Q4, Q5 is turn-offed because its grid voltage drags down, simultaneously, resistance R 5 is coupled to the high voltage of the negative pole P-of electric discharge port at the voltage sample end (VM) of battery protection chip U1, when this voltage is greater than inner reference voltage (0.3V), control of discharge end (DO) output low level of battery protection chip U1, metal-oxide-semiconductor Q2 turn-offs because its grid loses voltage, after this, the voltage one of the negative pole P-of electric discharge port is added to the voltage sample end (VM) of battery protection chip U1 straight through resistance R 5, make the control of discharge end (DO) of battery protection chip U1 continue output LOW voltage, metal-oxide-semiconductor Q2 is locked in off state, the discharge path of battery is locked to off-state.
In addition; it should be noted that; before charging voltage in capacitor C 6 reaches the grid threshold voltage of metal-oxide-semiconductor Q6; because metal-oxide-semiconductor Q4, Q5 are in conducting state; the high voltage of the negative pole P-of electric discharge port can not be added to the voltage sample end (VM) of battery protection chip U1; the control of discharge end (DO) of battery protection chip U1 is high voltage always; metal-oxide-semiconductor Q2 is because be subject to the control of metal-oxide-semiconductor Q3 to work in interruption opening state always; overcurrent waveform is continuous arteries and veins string, and first pulse ratio pulse amplitude is below higher.
At metal-oxide-semiconductor Q2, be locked in after off state; only have and remove the load accessing on electric discharge port; the voltage of the negative pole P-of electric discharge port is just lowered; if the voltage of the voltage sample end (VM) of battery protection chip U1 drops to below inner reference voltage (0.3V); the control of discharge end (DO) of battery protection chip U1 is output HIGH voltage; metal-oxide-semiconductor Q2 obtains high voltage conducting again because of grid, and it is open-minded that discharge path recovers.In addition, on the grid of metal-oxide-semiconductor Q2, series resistor R6 can reduce the speed of opening of metal-oxide-semiconductor Q2, and further reduces the transient peak electric current of battery discharge.
Fig. 4 is the circuit diagram of the current foldback circuit embodiment tri-of the utility model battery discharge, and this embodiment compares the embodiment shown in Fig. 3, and the circuit structure of time delay module is identical, and difference is only in control of discharge module.The circuit structure of the control of discharge module of this embodiment is only described below, in this control of discharge module, it is the chip of AD8566 that operational amplifier U2 selects model, this chip comprises two parts, the sampled voltage on sampling resistor R4 amplifies as amplifier in first, and second portion comes relatively this sampled voltage and reference voltage as comparator.Certainly, in other embodiments, also can select separated amplifier and comparator.In addition, in this embodiment, sampling resistor R4 is connected between the electric discharge anodal P+ of port and the positive pole of battery core B1, and, the first end of sampling resistor R4 connects the first input end (B-INPUT) of operational amplifier U2 first by resistance R 10, the second end of sampling resistor R4 connects second input (B+INPUT) of operational amplifier U2 first by resistance R 22, resistance R 23 is connected between second input (B+INPUT) and ground of operational amplifier U2 first, the output of the first of operational amplifier U2 (B OUTPUT) connects the first input end (A+INPUT) of the second portion of operational amplifier U2, second input (A-INPUT) of the second portion of operational amplifier U2 meets reference voltage Verf, the output of the second portion of operational amplifier U2 (A OUTPUT) connects the grid of metal-oxide-semiconductor Q3, the source ground of metal-oxide-semiconductor Q3, the drain electrode of metal-oxide-semiconductor Q3 connects the grid of metal-oxide-semiconductor Q2, the drain electrode of metal-oxide-semiconductor Q2 connects the drain electrode of metal-oxide-semiconductor Q1, the source electrode of metal-oxide-semiconductor Q1 meets the negative pole P-of electric discharge port, the grid of metal-oxide-semiconductor Q2 connects the control of discharge end (DO) of battery protection chip U1 by resistance R 6, the grid of metal-oxide-semiconductor Q1 connects the charging control end (CO) of battery protection chip U1.In addition, between second input (A-INPUT) of the second portion of operational amplifier U2 and ground, be also connected with capacitor C 7, the power end of operational amplifier U2 (V+) connects the positive pole of battery core B1, and, between the power end of operational amplifier U2 (V+) and ground, be also connected with capacitor C 5.
The course of work and the embodiment shown in Fig. 3 bis-of the current foldback circuit of the battery discharge of this embodiment are roughly the same; difference is only; sampling resistor R4 is connected in the positive pole of electric discharge port, obtains the voltage on this sampling resistor R4 with an amplifier simultaneously, can improve antijamming capability like this.Concrete reason is: if sampling resistor is arranged on the negative pole of electric discharge port, because of the negative pole of electric discharge port general all directly and the grounding shell of main frame be connected together, jamproof ability is relatively poor.
Fig. 5 is the circuit diagram of the current foldback circuit embodiment tetra-of the utility model battery discharge, illustrates the control of discharge module of this embodiment and the structure of time delay module below.
In this control of discharge module, the negative pole of the first termination battery core B2 of sampling resistor R4, the source electrode of the second termination metal-oxide-semiconductor Q2 of sampling resistor R4, the second end of sampling resistor R4 also connects the source electrode of metal-oxide-semiconductor Q3, the drain electrode of metal-oxide-semiconductor Q2 connects the drain electrode of metal-oxide-semiconductor Q1, the source electrode of metal-oxide-semiconductor Q1 meets the negative pole P-of electric discharge port, the grid of metal-oxide-semiconductor Q1 connects the charging control end (CO) of battery protection chip U1, the grid of metal-oxide-semiconductor Q2 connects the positive pole of diode D2, the negative pole of diode D2 connects the control of discharge end (DO) of battery protection chip U1, the drain electrode of metal-oxide-semiconductor Q3 connects the voltage sample end (VM) of battery protection chip U1 by resistance R 13, the control of discharge end (DO) of the first termination battery protection chip U1 of resistance R 11, the second end of resistance R 11 connects respectively the grid of metal-oxide-semiconductor Q3 and the first end of capacitor C 7, the second end ground connection of capacitor C 7.In addition, resistance R 6 is connected between the control of discharge end (DO) and the grid of metal-oxide-semiconductor Q2 of battery protection chip U1, reduces the transient current of battery discharge to reduce the speed of opening of Q2.The positive pole of diode D3 is by resistance R 14 ground connection, and the negative pole of diode D3 connects the grid of metal-oxide-semiconductor Q3.
In time delay module; the positive pole of diode D1 connects the negative pole P-of electric discharge port; the negative pole of diode D1 connects the first end of capacitor C 6 and the grid of metal-oxide-semiconductor Q6 by resistance R 8; the second end of capacitor C 6 and the source ground of metal-oxide-semiconductor Q6; the drain electrode of metal-oxide-semiconductor Q6 connects the grid of metal-oxide-semiconductor Q3; the negative pole P-of electric discharge port also connects the voltage sample end (VM) of battery protection chip U1 by resistance R 5, resistance R 9 is connected between the negative pole and ground of diode D1, for C6 provides discharge path.
The following describes the course of work of current foldback circuit of the battery discharge of this embodiment: when by after load access electric discharge port; charging control end (CO) and the control of discharge end (DO) of battery protection chip U1 are all exported high level, and metal-oxide-semiconductor Q1, Q2 are open-minded.Now, the output voltage of battery battery core forms discharge path through electric discharge port, metal-oxide-semiconductor Q1, Q2.If normal condition; during without generation electric discharge overcurrent; when control of discharge end (DO) output HIGH voltage of battery protection chip U1; by resistance R 11, be capacitor C 7 chargings; make the voltage of capacitor C 7 higher than the gate-on voltage of metal-oxide-semiconductor Q3; metal-oxide-semiconductor Q3 conducting; voltage on sampling resistor R4 is coupled to the voltage sample end (VM) of battery protection chip U1 by metal-oxide-semiconductor Q3, resistance R 13; if this voltage is lower than the reference voltage (0.3V) of the inside of battery protection chip U1; the control of discharge end (DO) of battery protection chip U1 continues output high level, sustain discharge path.
When there is overcurrent, the voltage on sampling resistor R4 is higher than the reference voltage (0.3V) of the inside of battery protection chip U1, control of discharge end (DO) output low level of battery protection chip U1, and metal-oxide-semiconductor Q2 turn-offs, and discharge path disconnects.When closing, metal-oxide-semiconductor Q2 has no progeny; voltage drop on sampling resistor R4, when again lower than the reference voltage (0.3V) of the inside of battery protection chip U1, the control of discharge end (DO) of battery protection chip U1 is exported again high level; metal-oxide-semiconductor Q2 conducting, discharge path is again open-minded.Like this, metal-oxide-semiconductor Q2 is operated in and is interrupted the state of opening.At this, it should be noted that, at metal-oxide-semiconductor Q2 off period, due to the voltage of capacitor C 7 step-down suddenly not, therefore, metal-oxide-semiconductor Q3 continues conducting.In order further to guarantee the gate-on voltage higher than metal-oxide-semiconductor Q3 at the voltage of metal-oxide-semiconductor Q2 off period capacitor C 7, the high voltage of the negative pole P-of the port that also can make to discharge is capacitor C 7 chargings by resistance R 14, diode D3.
In addition, at metal-oxide-semiconductor Q2 blocking interval, the voltage of the negative pole P-of electric discharge port is elevated, and this voltage is by diode D1,6 chargings of 8 pairs of capacitor C of resistance R.Because metal-oxide-semiconductor Q2 during overcurrent is interrupted to turn-off, so, the charging of capacitor C 6 is repeatedly accumulated.Along with the voltage rising of capacitor C 6, before reaching the turn-on threshold voltage of metal-oxide-semiconductor Q6, metal-oxide-semiconductor Q2 is operated in interruption off state.If reach the turn-on threshold voltage of metal-oxide-semiconductor Q6, metal-oxide-semiconductor Q6 is open-minded, metal-oxide-semiconductor Q3 grid voltage is dragged down, simultaneously, resistance R 5 is coupled to the high voltage of the negative pole P-of electric discharge port at the voltage sample end (VM) of battery protection chip U1, when this voltage is greater than inner reference voltage (0.3V), control of discharge end (DO) output low level of battery protection chip U1, metal-oxide-semiconductor Q2 turn-offs because its grid loses voltage, after this, the voltage one of the negative pole P-of electric discharge port is added to the voltage sample end (VM) of battery protection chip U1 straight through resistance R 5, make the control of discharge end (DO) of battery protection chip U1 continue output LOW voltage, metal-oxide-semiconductor Q2 is locked in off state, the discharge path of battery is locked to off-state.
The current foldback circuit of the battery discharge of this embodiment is compared the embodiment shown in Fig. 3 and Fig. 4, can save a comparator or amplifier, and time delay module can be saved some switching tubes (for example metal-oxide-semiconductor Q4, Q5), and therefore, structure is simpler.
About the several circuit diagrams shown in above, should understand this is several embodiment of the present utility model, and in other embodiments, metal-oxide-semiconductor can select the switching tube of other type to substitute, some resistance that play metering function can save, and some electric capacity that play voltage stabilizing and filter action can save.And, also can use current sensor that the electric discharge positive pole of port or the current conversion of discharge end negative pole are become to voltage.
Fig. 6 is the flow chart of the over-current protection method embodiment mono-of the utility model battery discharge, and the over-current protection method of this battery discharge comprises:
A. detect in real time the discharging current of battery, and judge whether to occur overcurrent by the discharging current that relatively detects and default threshold value, if not, perform step B; If so, perform step C;
B. controlled discharge switching tube is open-minded, then performs step A;
C. controlled discharge switching tube turn-offs, and meanwhile, by relatively there is the time of overcurrent and default delay time, judges that whether overcurrent is overtime, if so, performs step D; If not, perform step A;
D. described discharge switch pipe is locked in to off state, then finishes.
In step C, can judge that whether overcurrent is overtime by method below:
When discharge switch pipe turn-offs, high voltage charges to the first electric capacity by the second resistance, and overtime by judging that the voltage of the first electric capacity judges whether, wherein, default delay time is relevant with the capacitance of described the first electric capacity to the resistance of described the second resistance.
The foregoing is only preferred embodiment of the present utility model, be not limited to the utility model, for a person skilled in the art, the utility model can have various modifications and variations.All within spirit of the present utility model and principle, any modification of doing, be equal to replacement, improvement etc., within all should being included in claim scope of the present utility model.
Claims (6)
1. a current foldback circuit for battery discharge, comprises the discharge switch pipe being connected in battery discharge path, it is characterized in that, described current foldback circuit also comprises control of discharge module and is connected in the time delay module of described control of discharge module; Wherein,
Described control of discharge module comprises battery protection chip, sampling resistor, comparator, Current limited Control switching tube, wherein, the first end of described sampling resistor connects respectively negative pole and the ground of described battery, the second end of discharge switch pipe and the first input end of described comparator described in the second termination of described sampling resistor, the negative pole of the first termination discharge end mouth of described discharge switch pipe, the second input termination reference voltage of described comparator, the control end of Current limited Control switching tube described in the output termination of described comparator, the second end ground connection of described Current limited Control switching tube, the first end of described Current limited Control switching tube connects respectively the control end of described discharge switch pipe and the control of discharge end of described battery protection chip,
Described time delay module comprises the first diode, the first switching tube, second switch pipe, the first electric capacity, the first resistance, the second resistance, the 3rd resistance and the 4th resistance, wherein, the voltage sample end of battery protection chip described in the first termination of described the first switching tube, the second end of the second end of described the first switching tube and second switch pipe is ground connection respectively, and the first end of the control end of described the first switching tube and described second switch pipe connects the negative pole of described electric discharge port by described the first resistance; The positive pole of described the first diode connects the negative pole of described electric discharge port; the negative pole of described the first diode connects the first end of described the first electric capacity and the control end of described second switch pipe by described the second resistance; the second end ground connection of described the first electric capacity; the negative pole of described electric discharge port also connects the voltage sample end of described battery protection chip by described the 3rd resistance, described the 4th resistance is connected between the negative pole and ground of described the first diode.
2. the current foldback circuit of battery discharge according to claim 1; it is characterized in that; described control of discharge module also comprises current-limiting resistance; the first end of described current-limiting resistance is connected to the control of discharge end of described battery protection chip, and the second end of described current-limiting resistance connects the control end of described discharge switch pipe and the first end of described Current limited Control switching tube.
3. a current foldback circuit for battery discharge, comprises the discharge switch pipe being connected in battery discharge path, it is characterized in that, described current foldback circuit also comprises control of discharge module and is connected in the time delay module of described control of discharge module; Wherein,
Described control of discharge module comprises battery protection chip, sampling resistor, comparator, amplifier, Current limited Control switching tube, wherein, the first end of described sampling resistor connects respectively the first input end of the anodal and described amplifier of described battery, the second end of described sampling resistor connects respectively the second input of the anodal and described amplifier of electric discharge port, the first input end of comparator described in the output termination of described amplifier, the second input termination reference voltage of described comparator, the control end of Current limited Control switching tube described in the output termination of described comparator, the second end ground connection of described Current limited Control switching tube, the first end of described Current limited Control switching tube connects respectively the control end of described discharge switch pipe and the control of discharge end of described battery protection chip, the negative pole of the first termination discharge end mouth of described discharge switch pipe, the second end of described discharge switch pipe connects respectively negative pole and the ground of battery,
Described time delay module comprises the first diode, the first switching tube, second switch pipe, the first electric capacity, the first resistance, the second resistance, the 3rd resistance and the 4th resistance, wherein, the voltage sample end of battery protection chip described in the first termination of described the first switching tube, the second end of the second end of described the first switching tube and second switch pipe is ground connection respectively, and the first end of the control end of described the first switching tube and described second switch pipe connects the negative pole of described electric discharge port by described the first resistance; The positive pole of described the first diode connects the negative pole of described electric discharge port; the negative pole of described the first diode connects the first end of described the first electric capacity and the control end of described second switch pipe by described the second resistance; the second end ground connection of described the first electric capacity; the negative pole of described electric discharge port also connects the voltage sample end of described battery protection chip by described the 3rd resistance, described the 4th resistance is connected between the negative pole and ground of described the first diode.
4. the current foldback circuit of battery discharge according to claim 3; it is characterized in that; described control of discharge module also comprises current-limiting resistance; the first end of described current-limiting resistance is connected to the control of discharge end of described battery protection chip, and the second end of described current-limiting resistance connects the control end of described discharge switch pipe and the first end of described Current limited Control switching tube.
5. a current foldback circuit for battery discharge, comprises the discharge switch pipe being connected in battery discharge path, it is characterized in that, described current foldback circuit also comprises control of discharge module and is connected in the time delay module of described control of discharge module; Wherein,
Described control of discharge module comprises battery protection chip, sampling resistor, Current limited Control switching tube, the 5th resistance, the 6th resistance, the second electric capacity and the second diode, wherein, the first end of described sampling resistor connects respectively negative pole and the ground of described battery, the second end of described sampling resistor connects respectively the second end of described discharge switch pipe and the second end of described Current limited Control switching tube, the negative pole of the first termination discharge end mouth of described discharge switch pipe, the positive pole of the second diode described in the control termination of described discharge switch pipe, the negative pole of described the second diode connects the control of discharge end of described battery protection chip, described the 6th resistance is connected between the positive pole and negative pole of described the second diode, the voltage sample end of battery protection chip described in the first termination of described Current limited Control switching tube, the control of discharge end of battery protection chip described in the first termination of described the 5th resistance, the second end of described the 5th resistance connects respectively the control end of described Current limited Control switching tube and the first end of described the second electric capacity, the second end ground connection of described the second electric capacity,
Described time delay module comprises the first diode, the second resistance, the 3rd resistance, the 4th resistance, the first electric capacity and second switch pipe, wherein, the positive pole of described the first diode connects the negative pole of described electric discharge port, the negative pole of described the first diode connects the first end of described the first electric capacity and the control end of described second switch pipe by described the second resistance, the second end ground connection of the second end of described the first electric capacity and described second switch pipe, the first end of described second switch pipe connects the control end of described Current limited Control switching tube, the negative pole of described electric discharge port also connects the voltage sample end of described battery protection chip by described the 3rd resistance, described the 4th resistance is connected between the negative pole and ground of described the first diode.
6. the current foldback circuit of battery discharge according to claim 5; it is characterized in that; described control of discharge module also comprises the 3rd diode and the 7th resistance; wherein; the negative pole of described the 3rd diode connects the control end of described Current limited Control switching tube, and the positive pole of described the 3rd diode connects the negative pole of described electric discharge port by described the 7th resistance.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320828682.6U CN203839985U (en) | 2013-12-13 | 2013-12-13 | Cell discharge overcurrent protection circuit |
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| CN201320828682.6U CN203839985U (en) | 2013-12-13 | 2013-12-13 | Cell discharge overcurrent protection circuit |
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| CN203839985U true CN203839985U (en) | 2014-09-17 |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103647323A (en) * | 2013-12-13 | 2014-03-19 | 海能达通信股份有限公司 | Cell discharge overcurrent protection circuit and cell discharge overcurrent protection method |
| CN104795807A (en) * | 2015-04-16 | 2015-07-22 | 上海空间电源研究所 | High-reliability current protecting circuit for astronavigation |
| CN105203962A (en) * | 2015-08-31 | 2015-12-30 | 北汽福田汽车股份有限公司 | Vehicle-mounted battery over-current diagnostic method and device |
| US10090689B2 (en) | 2013-12-13 | 2018-10-02 | Hytera Communications Corp., Ltd. | Overcurrent protection circuit and method for limiting discharge current of battery within safety limiting value |
| CN111864819A (en) * | 2019-04-30 | 2020-10-30 | 松下电气机器（北京）有限公司 | Control device and method for storage battery |
| CN114139224A (en) * | 2021-11-20 | 2022-03-04 | 苏州浪潮智能科技有限公司 | Protection device of server and server |
| CN115172912A (en) * | 2022-09-07 | 2022-10-11 | 禹创半导体(深圳)有限公司 | Method for prolonging standby time of battery by battery protection chip |
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- 2013-12-13 CN CN201320828682.6U patent/CN203839985U/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103647323A (en) * | 2013-12-13 | 2014-03-19 | 海能达通信股份有限公司 | Cell discharge overcurrent protection circuit and cell discharge overcurrent protection method |
| US10090689B2 (en) | 2013-12-13 | 2018-10-02 | Hytera Communications Corp., Ltd. | Overcurrent protection circuit and method for limiting discharge current of battery within safety limiting value |
| CN104795807A (en) * | 2015-04-16 | 2015-07-22 | 上海空间电源研究所 | High-reliability current protecting circuit for astronavigation |
| CN104795807B (en) * | 2015-04-16 | 2018-02-06 | 上海空间电源研究所 | A kind of aerospace high reliability current protecting circuit |
| CN105203962A (en) * | 2015-08-31 | 2015-12-30 | 北汽福田汽车股份有限公司 | Vehicle-mounted battery over-current diagnostic method and device |
| CN111864819A (en) * | 2019-04-30 | 2020-10-30 | 松下电气机器（北京）有限公司 | Control device and method for storage battery |
| CN114139224A (en) * | 2021-11-20 | 2022-03-04 | 苏州浪潮智能科技有限公司 | Protection device of server and server |
| CN114139224B (en) * | 2021-11-20 | 2023-11-21 | 苏州浪潮智能科技有限公司 | Protection device of server and server |
| CN115172912A (en) * | 2022-09-07 | 2022-10-11 | 禹创半导体(深圳)有限公司 | Method for prolonging standby time of battery by battery protection chip |
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