CN104518477A

CN104518477A - Circuit protection device, circuit protection method and circuit protection equipment

Info

Publication number: CN104518477A
Application number: CN201310456183.3A
Authority: CN
Inventors: 巩小飞; 林美爱; 张涛
Original assignee: O2Micro International Ltd
Current assignee: O2Micro International Ltd
Priority date: 2013-09-29
Filing date: 2013-09-29
Publication date: 2015-04-15

Abstract

The invention relates to a circuit protection device, a circuit protection method, and a piece of circuit protection equipment. The circuit protection device comprises a first switch coupled between a load and a power supply used for powering the load, and a controller coupled to the first switch. The controller is used for switching off the first switch when judging that an abnormality occurs according to a first signal, and switching on the first switch when judging that the abnormality is eliminated according to a second signal and a third signal, wherein the first signal indicates the current flowing through the load when the first switch is switched on, the second signal indicates the power voltage of the power supply, and the third signal indicates the load voltage of the load. By adopting the circuit protection device and the circuit protection method provided by the invention, an abnormal state can be identified accurately, over-current protection can be provided, the circuit can recover from the over-current protection state in a timely manner, and almost no security risks exist.

Description

Circuit protection device, method and equipment

Technical field

The invention belongs to electronic circuit field, relate to a kind of circuit protection device, circuit protection method and electric circuit protection equipment.

Background technology

Usually circuit protection mechalusm is adopted in the circuit of the products such as electric motor car; when for there are load abnormal (such as short circuit etc.) in circuit; make circuit enter overcurrent protection state (such as cut off the electricity supply and path) between load, the power supply caused to avoid overcurrent etc. damages.

The overcurrent protection scheme of traditional electric motor car normally realizes with air switch; when current is excessive; switch contact is separated by magnetic force by the magnetictrip of air switch; operation principle due to traditional air switch overcurrent protection elevates the temperature based on big current; and then make switch produce mechanical deformation; major loop switch could be cut off, therefore use the overcurrent protection response time of air switch excessively slow, and protection precision is low.And, in the prior art, in order to make the circuit entering overcurrent protection state be restored to normal operating conditions (such as reclosing the path between power supply and load), usually needing manual intervention, such as, manually being recovered by force by external switch.But this mode makes circuit cannot return to normal operating conditions easily in time, makes troubles to user.

In addition, in prior art, also adopt a kind of means of Timed Recovery, namely after circuit enters the stipulated time that overcurrent protection state rises, automatically restore to normal operating conditions.But, in some cases, extremely also may exist at stipulated time back loading, therefore adopt and there is potential safety hazard in this way.

Summary of the invention

In view of the above-mentioned defect of prior art, the technical problem to be solved in the present invention is, enables the circuit entering overcurrent protection state return to normal operating conditions voluntarily in time, and there is not potential safety hazard.

In order to solve the problems of the technologies described above, according to an aspect of the present invention, provide a kind of circuit protection device, comprising: the first switch, be coupled in load and between the power supply for described load supplying; And controller, be coupled in described first switch, for when judging to occur abnormal according to the first signal, disconnect described first switch, the electric current of described load is flowed through during the first switch connection described in wherein said first signal designation, and when described first switch disconnects, when judging that described exception is eliminated according to secondary signal and the 3rd signal, connect described first switch, wherein said secondary signal indicates the supply voltage of described power supply, the load voltage of load described in described 3rd signal designation.

According to a further aspect in the invention, also proposed a kind of circuit protection method, comprising: when being coupled in load and for the first switch connection between the power supply for described load supplying, detect the first signal that instruction flows through the electric current of described load; Judge whether to have occurred exception according to described first signal, and disconnect described first switch when being judged that there is abnormal; When described first switch disconnects, detect the 3rd signal of the secondary signal of the supply voltage of the described power supply of instruction and the load voltage of the described load of instruction; And judge whether described exception is eliminated according to described secondary signal and described 3rd signal, and connect described first switch when judging that described exception is eliminated.

According to a further aspect of the invention, additionally provide a kind of electric circuit protection equipment, this electric circuit protection equipment comprises power supply, load and is coupled in the circuit protection device of described power supply and described load, wherein said circuit protection device comprises: the first switch, is coupled in load and between the power supply for described load supplying; And controller, be coupled in described first switch, described load and described power supply, for when judging to occur abnormal according to the first signal, disconnect described first switch, the electric current of described load is flowed through during the first switch connection described in wherein said first signal designation, and when described first switch disconnects, when judging that described exception is eliminated according to secondary signal and the 3rd signal, connect described first switch, wherein said secondary signal indicates the supply voltage of described power supply, the load voltage of load described in described 3rd signal designation.

According to other side of the present invention; additionally provide corresponding computer-readable recording medium; this computer-readable recording medium stores the computer program that can be performed by computing equipment, described program can make described computing equipment perform foregoing circuit guard method when performing.

According to circuit protection device provided by the invention, circuit protection method and electric circuit protection equipment; by eliminating in the exception judging to trigger overcurrent protection based on supply voltage and load voltage; automatic connection is as the first switch of overcurrent protective switch; can realizing circuit voluntarily in time from overcurrent protection recovering state, and there is potential safety hazard hardly.In addition; circuit protection device provided by the invention, circuit protection method and electric circuit protection equipment can also accurate identification circuit proterctive equipment (such as electric motor car, the electric tool) abnormal currents under different working modes; to provide different overcurrent protection mechanism, improve circuit protection precision.

According to below with reference to the accompanying drawings to detailed description of illustrative embodiments, further feature of the present invention and aspect will become clear.

Accompanying drawing explanation

Comprise in the description and form the accompanying drawing of a part for specification and specification together illustrates exemplary embodiment of the present invention, characteristic sum aspect, and for explaining principle of the present invention.

Schematic diagram when Fig. 1 illustrates that circuit protection device is according to an embodiment of the invention applied to the electric circuit protection equipment comprising power supply and load;

Fig. 2 illustrates the schematic diagram of a kind of possibility execution mode of the controller in circuit protection device shown in Fig. 1;

Fig. 3 illustrates the schematic diagram of the another kind possibility execution mode of the controller in circuit protection device shown in Fig. 1;

Fig. 4 illustrates the schematic diagram of a kind of possibility execution mode of mode checking unit shown in Fig. 3;

Schematic diagram when Fig. 5 illustrates that circuit protection device is according to another embodiment of the present invention applied to the electric circuit protection equipment comprising power supply and load;

Fig. 6 illustrates the schematic diagram of a kind of possible execution mode of the over-current detection unit in the controller in circuit protection device shown in Fig. 5;

Fig. 7 illustrates schematic diagram when being applied to according to the circuit protection device of further embodiment of this invention the electric circuit protection equipment comprising power supply and load;

Fig. 8 illustrates schematic diagram when being applied to according to the circuit protection device of further embodiment of this invention the electric circuit protection equipment comprising power supply and load;

Fig. 9 illustrates the indicative flowchart of circuit protection method according to an embodiment of the invention;

Figure 10 illustrates the indicative flowchart judging the abnormal a kind of possible execution mode whether eliminated in circuit protection method shown in Fig. 9;

Figure 11 illustrates the indicative flowchart of circuit protection method according to another embodiment of the present invention;

Figure 12 illustrates the indicative flowchart of a kind of possible execution mode of the testing pattern in circuit protection method shown in Figure 11;

Figure 13 illustrates the indicative flowchart judging the abnormal a kind of possible execution mode whether eliminated in circuit protection method shown in Figure 11;

Figure 14 illustrates the indicative flowchart of the circuit protection method according to further embodiment of this invention;

Figure 15 illustrates that the indicative flowchart of abnormal a kind of possible execution mode has appearred in judging whether in circuit protection method shown in Figure 14.

Embodiment

Various exemplary embodiment of the present invention, characteristic sum aspect is described in detail below with reference to accompanying drawing.The same or analogous element of Reference numeral presentation function identical in accompanying drawing.Although the various aspects of embodiment shown in the drawings, unless otherwise indicated, accompanying drawing need not be drawn in proportion.

Word " exemplary " special here means " as example, embodiment or illustrative ".Here need not be interpreted as being better than or being better than other embodiment as any embodiment illustrated by " exemplary ".

In addition, in order to better the present invention is described, in embodiment hereafter, give numerous details.It will be appreciated by those skilled in the art that do not have these details, the present invention can implement equally.In other example, known method, means, element and circuit are not described in detail, so that highlight purport of the present invention.

Fig. 1 shows schematic diagram when circuit protection device 100 is according to an embodiment of the invention applied to the electric circuit protection equipment comprising power supply 200 and load 300.In one embodiment, electric circuit protection equipment can be electric motor car, such as electric bicycle, battery-operated motor cycle, electro-tricycle, Segway Human Transporter, electric automobile etc.In another embodiment, electric circuit protection equipment also can be electric tool.The battery pack that power supply 200 can be multiple serial battery and/or be connected in parallel and formed, such as rechargeable lithium battary or lead acid accumulator.

As shown in Figure 1, in this embodiment, circuit protection device 100 comprises the first switch 110 and controller 120.Wherein, the first switch 110 is coupled in load 300 and between the power supply 200 of powering for load 300.Controller 120 is coupled in the first switch 110, power supply 200 and load 300, be mainly used in: when there is abnormal (such as including but not limited to that the abnormal conditions such as overcurrent, short circuit appear in load 300) according to the first signal judging circuit, disconnect the first switch 110, to stop powering to load 300, wherein said first signal designation flows through the electric current I of load 300 via the first switch 110; And, when the first switch 110 disconnects, when judging that described exception is eliminated according to secondary signal (not shown in figure 1) and the 3rd signal (not shown in figure 1), connect the first switch 110, the wherein supply voltage Vb of secondary signal instruction power supply 200, the load voltage Vl of the 3rd signal designation load 300.Controller 120 in this embodiment, when decision circuit is eliminated extremely, is connected the first switch 110, is achieved recovering in time voluntarily of circuit.In addition, because this recovery carries out when judging abnormal elimination, therefore there is potential safety hazard hardly.

In this embodiment, controller 120 judges abnormal whether elimination according to the 3rd signal of the secondary signal of instruction supply voltage Vb and instruction load voltage Vl, such as when disconnection first switch 110 (i.e. deenergization 200, load 300 form via the first switch 110 performance loop), judge by the secondary signal of the instruction supply voltage Vb in measure loop (not shown in figure 1) and the 3rd signal of instruction load voltage Vl.Specifically, circuit abnormality is mainly because there is abnormal (such as short circuit, overcurrent etc.) in load 300, and therefore, controller 120 is by judging whether load 300 recovers normally to determine whether described exception is eliminated.In one embodiment, for judging whether load 300 recovers normal, controller 120 can calculate the equiva lent impedance of load 300 according to the secondary signal of the 3rd signal of instruction load voltage Vl and instruction supply voltage Vb, and determines whether above-mentioned exception is eliminated according to the magnitude relationship between the equiva lent impedance of calculated load 300 and the normal equiva lent impedance of load 300 under normal circumstances.Such as, if calculate load 300 equiva lent impedance be not less than the normal equiva lent impedance of load 300, then illustrate that load 300 has recovered normal, otherwise illustrate that load 300 not yet recovers normal.

In addition, due to when supply voltage Vb is certain, load voltage Vl(such as, the dividing potential drop in load 300) can the size of the direct equiva lent impedance of reflected load 300.Therefore, in another embodiment, controller 120 can after the 3rd signal (both end voltage of such as load 300) of secondary signal (such as the both end voltage of power supply 200) and instruction load voltage V1 that current instruction supply voltage Vb detected, according to current detection to load voltage Vl and supply voltage Vb under load 300 normal partial pressure (i.e. the both end voltage of load 300 when supply voltage Vb powers lower normal work) between magnitude relationship, judge whether load 300 recovers normal.Such as, if load voltage Vl is not less than the normal partial pressure of load 300, then illustrates that load 300 has recovered normal, otherwise illustrate that load 300 not yet recovers normal.

Below provide several embodiment judging extremely whether eliminate according to load voltage Vl and supply voltage Vb.But those skilled in the art will be understood that and the invention is not restricted to following execution mode, as long as abnormal whether elimination can be judged according to supply voltage Vb and load voltage Vl.

Fig. 2 shows the schematic diagram of a kind of possible execution mode of the controller 120 in circuit protection device 100 shown in Fig. 1.Composition graphs 1 is described by Fig. 2, and element identical with Fig. 1 label in Fig. 2 has similar function.As shown in Figure 2, in this embodiment, controller 120 can comprise memory cell 121 and load detecting unit 122.

Wherein, memory cell 121 is for storing the first reference signal Vb of at least one group of instruction supply voltage explicitly _refwith the second reference signal Vl of instruction load voltage _re.Load detecting unit 122 is coupled with memory cell 121, first switch 110, load 200 and power supply 300, for the first reference signal Vb stored in the secondary signal according to instruction supply voltage Vb, the 3rd signal indicating load voltage Vl and memory cell 121 _refwith the second reference signal Vl _refjudge abnormal whether elimination.

In one example, load detecting unit 122 can comprise the first computing module 122a and the first judge module 122b as shown in Figure 2, wherein: the first computing module 122a is coupled in memory cell 121, load 200 and power supply 300, for the first reference signal Vb of the secondary signal according to instruction supply voltage Vb, memory cell 121 storage _refwith the second reference signal Vl _ref, calculate the load voltage reference value that is associated with secondary signal using as first threshold V _th; And first judge module 122b be coupled in the first computing module 122a and the first switch 110, for comparing the 3rd signal and first threshold V _th, and judge abnormal whether elimination according to comparative result.

In this example, in memory cell 121, store the first reference signal Vb of at least one group of instruction supply voltage explicitly _refwith the second reference signal Vl of instruction load voltage _ref.Such as, what memory cell 121 stored can be represent the first reference signal Vb _refwith the second reference signal Vl _refthe tables of data of corresponding relation or characteristic curve.In one embodiment, can in advance when circuit normally work, at the first reference signal Vb of different instruction supply voltages _reflower the second reference signal Vl measuring instruction load voltage _ref, set up above-mentioned corresponding relation.Such as, when guaranteeing that circuit normally works, at the first reference signal Vb of instruction first supply voltage _ref_ 1 time is measured the second reference signal obtaining instruction first load voltage is Vl _ref_ 1, at the first reference signal Vb of instruction second source voltage _ref_ 2 times are measured the second reference signal obtaining instruction second load voltage is Vl _ref_ 2, memory cell 121 can store and comprise Vb _ref_ 1 and Vl _ref_ 1, Vb _ref_ 2 and Vl _refthe tables of data of _ 2 liang of group corresponding relations.

But it is apparent to those skilled in the art that in memory cell 121 and can include but not limited to two groups of first reference signal Vb be associated with storing _refwith the second reference signal Vl _ref, can also be that other organizes number arbitrarily.The secondary signal of the first computing module 122a according to instruction supply voltage Vb, the first reference signal Vb of memory cell 121 storage _refwith the second reference signal Vl _ref, calculate the load voltage reference value that is associated with secondary signal using as first threshold V _th.Specifically, the first computing module 122a can by the first reference signal Vb be associated with storing in memory cell 121 _refwith the second reference signal Vl _reftables of data or characteristic curve, calculate the load voltage reference value corresponding with the secondary signal of described instruction supply voltage Vb, using as first threshold V _th.

In one example, such as, store two group of first reference signal and the second reference signal (such as Vb in memory cell 121 _ref_ 1 and Vl _ref_ 1, Vb _ref_ 2 and Vl _ref_ 2) tables of data be associated with storing, the first reference signal Vb in the secondary signal and memory cell 121 of instruction supply voltage Vb _ref_ 1 identical time, then the first computing module 122a calculates the load voltage reference value be associated with secondary signal is Vl _ref_ 1, and by Vl _ref_ 1 as first threshold V _th.In another example, if the first reference signal Vb of secondary signal in memory cell 121 of instruction supply voltage Vb _ref_ 1 and Vb _ref(i.e. Vb between _ 2 _ref_ 1< secondary signal <Vb _ref_ 2) time, then the first computing module 122a is according to the first reference signal and the second reference signal (such as Vb _ref_ 1 and Vl _ref_ 1, Vb _ref_ 2 and Vl _ref_ 2) determined curve characteristic (such as linear relationship) calculates the load voltage reference value be associated with secondary signal, using as first threshold V _th(V1 _ref_ 1<V _th<V1 _ref_ 2).

In addition, it should be appreciated by those skilled in the art, in other implementation of circuit protection device according to an embodiment of the invention, the first reference signal Vb that the first computing module 122a stores according to the secondary signal of instruction supply voltage Vb, memory cell 121 _refwith the second reference signal Vl _ref, other mode also can be adopted to calculate first threshold V _th, do not repeat them here.

First judge module 122b compares the 3rd signal and the first threshold V of instruction load voltage Vl _th, and come whether decision circuitry is abnormal eliminates according to comparative result.In one embodiment, when the first judge module 122b judges extremely to eliminate, send a control signal to the first switch 110, to make the first switch 100 connect, thus the automatic recovery of realizing circuit.

In one embodiment, controller 120 obtains the secondary signal of instruction supply voltage by the both end voltage detecting power supply 200, by detecting that the both end voltage of load 300 obtains the 3rd signal of instruction load voltage, correspondingly, first reference signal of the instruction supply voltage be associated with storing in memory cell 121 and the second reference signal of instruction load voltage are respectively the both end voltage of power supply 200 under normal circumstances and the both end voltage of load 300, then the first judge module 122b is not less than first threshold V at the 3rd signal of instruction load voltage Vl _thwhen, decision circuit is abnormal to be eliminated.Specifically, the first judge module 122b compares the 3rd signal and the first threshold V of instruction load voltage V1 _thif the 3rd signal is not less than first threshold V _th, the first judge module 122b decision circuit is abnormal to be eliminated, otherwise the first judge module 122b decision circuit is not eliminated extremely.That is, first threshold V is not less than at the 3rd signal of instruction load voltage V1 _thtime, illustrate that the both end voltage of present load 300 is not less than the both end voltage of load under normal circumstances 300, also just mean that the equiva lent impedance of the current reality of load 300 is not less than the normal equiva lent impedance of load 300, namely cause the load abnormal of the such as short circuit of overcurrent etc. to eliminate.

Example shown in Fig. 2 is according to the first reference signal Vb of at least one group of instruction supply voltage be associated with storing _refwith the second reference signal Vl of instruction load voltage _refcalculate, judge whether load abnormal is eliminated, but the present embodiment is not limited thereto.Such as, can also according to the first reference signal Vb of instruction supply voltage _refwith the second reference signal Vl of instruction load voltage _refbetween corresponding relation (such as Vb _refwith Vl _refbetween linear or nonlinear functional relation) carry out calculating and judging.Under the application scenarios that even substantially can not change at supply voltage Vb, the 3rd signal that also can arrange single threshold value and measured instruction load voltage Vl compares and judges.

Fig. 3 shows the schematic diagram of the possible execution mode of the another kind of the controller 120 in circuit protection device 100 shown in Fig. 1.Composition graphs 1 and Fig. 2 are described by Fig. 3, and element identical with Fig. 1, Fig. 2 label in Fig. 3 has similar function, does not repeat them here.A kind of possible example of this execution mode using electric motor car as load 300.But, it will be understood by those skilled in the art that the load 300 that the present invention applies is not limited to electric motor car, but the circuit needing any overcurrent protection can be applied to.

Controller 120 in embodiment illustrated in fig. 3 also comprises mode checking unit 123 compared to the controller 120 in Fig. 2.Mode checking unit 123 is coupled in power supply 200 and load 300, mainly for detection of the mode of operation of the electric circuit protection equipments such as such as electric motor car.

In this embodiment, the mode of operation of electric circuit protection equipment and at least one group can be indicated the first reference signal Vb of supply voltage by memory cell 121 _refand the second reference signal Vl of instruction load voltage _refstore explicitly.Further, the first computing module 122a is also coupled in mode checking unit 123, for the first reference signal Vb be associated with the mode of operation that mode checking unit 123 detects that the secondary signal according to instruction supply voltage Vb, memory cell 121 store _refwith the second reference signal Vl _ref, calculate the load voltage reference value be associated with secondary signal, using as first threshold V _th.

Electric circuit protection equipment is under different mode of operations (being such as in static condition, operating state etc.), and the first reference signal Vb of instruction same power supplies voltage _refsecond reference signal Vl of the instruction load voltage be associated _refmay be different.In one embodiment, the first reference signal Vb of instruction supply voltage can be stored respectively explicitly for different mode of operations _refwith the second reference signal Vl of instruction load voltage _ref, such as, set up the first reference signal Vb respectively for different mode of operations _refwith the second reference signal Vl _refthe tables of data of corresponding relation or characteristic curve.Like this, after the mode of operation that first computing module 122a detects from mode checking unit 123 receiving mode detecting unit 123, can according to the secondary signal of instruction supply voltage Vb, the first reference signal Vb of instruction supply voltage of storing explicitly with this mode of operation _refwith the second reference signal Vl of instruction load voltage _ref, calculate the first threshold V be associated with secondary signal under this mode of operation _th.

Advantageously, the circuit protection device 100 that controller 120 has structure as shown in Figure 3 can improve the abnormal precision eliminating judgement further, thus realizes better recovering voluntarily and eliminating safe hidden trouble in time.

Fig. 4 shows the schematic diagram of an example of mode checking unit 123 shown in Fig. 3.Composition graphs 3 is described by Fig. 4.In this embodiment, electric circuit protection equipment is electric motor car.As shown in Figure 4, mode checking unit 123 mainly comprises key detection module 123a, antitheft detection module 123b, handle acceleration detection module 123c and mode decision module 123d.

Wherein, whether key detection module 123a closes for the key switch detecting electric motor car.Whether antitheft detection module 123b is triggered for the burglar alarm detecting electric motor car.Whether handle acceleration detection module 123c exports for the handle signal for faster detecting electric motor car, when handle signal for faster exports by being driven the motor of electric motor car to run by electric machine controller, carries out speed regulating control.Mode decision module 123d is coupled in key detection module 123a, antitheft detection module 123b and handle acceleration detection module 123c, is mainly used in the mode of operation of the testing result determination electric motor car according to key detection module 123a, antitheft detection module 123b and handle acceleration detection module 123c.

In one embodiment, when key detection module 123a detects key switch disconnection and antitheft detection module 123b detects that burglar alarm is not triggered, mode decision module 123d judges that electric motor car is in the first mode of operation, and such as, electric motor car is in static condition; When key detection module 123a detects key switch disconnection and antitheft detection module 123b detects that burglar alarm is triggered, mode decision module 123d judges that electric motor car is in the second mode of operation, and such as, electric motor car is in alarm condition; When key detection module 123a detects that key switch closes and handle acceleration detection module 123c does not detect handle signal for faster, mode decision module 123d judges that electric motor car is in the 3rd mode of operation, and such as, electric motor car is in state to be sailed; And, when key detection module 123a detects that key switch closes and handle acceleration detection module 123c has detected handle signal for faster, mode decision module 123d judges that electric motor car is in the 4th mode of operation, and such as, electric motor car is in transport condition.

In this example, mode checking unit 123 according to condition adjudgement four kinds of mode of operations of the key switch detected, burglar alarm and handle signal for faster, thus can store the first reference signal Vb indicating supply voltage explicitly respectively with these four kinds of mode of operations in memory cell 121 _refwith the second reference signal Vl of instruction load voltage _ref.

But those skilled in the art will be understood that and the present invention is not limited thereto, the state of the miscellaneous parts such as the car light of electric motor car, pole changer can also be detected, and set more mode of operation as required.Such as, when detecting that key switch closes, can further according to car light state setting the 5th mode of operation and the 6th mode of operation.In addition, under the applied environment of other electric circuit protection equipments except electric motor car, also mode of operation can be judged according to other factor.

In one example, judge that electric motor car is in the 3rd mode of operation (such as at mode checking unit 123, electric motor car is in state to be sailed) or the 4th mode of operation (such as, electric motor car is in transport condition) when, controller 120 forbids load detecting unit 122.That is, if key detection module 123a detects that the key switch of electric motor car closes, then think that electric motor car is in state to be sailed (the 3rd mode of operation) or transport condition (the 4th mode of operation), consider that restore circuit may cause driving accident voluntarily, therefore controller 120 can be recovered not do voluntarily by forbidding load detecting unit 122, thus guarantees traffic safety.

In another example, also can by setting only when key detection module 123a detect that the key switch of electric motor car disconnects, load detecting unit 122 just carries out work, can reach the object as far as possible guaranteeing traffic safety equally.

Fig. 5 shows schematic diagram when circuit protection device 500 is according to another embodiment of the present invention applied to the electric circuit protection equipment comprising power supply 200 and load 300.

As shown in Figure 5; in this embodiment; circuit protection device 500 mainly comprises the first switch 510 and controller 520; and the major function of the first switch 510 and controller 520 respectively with embodiment illustrated in fig. 1 in the first switch 110 and the major function of controller 120 substantially similar, therefore not repeat them here.

But, mainly comprise memory cell 521, mode checking unit 522 and over-current detection unit 523 compared to the controller 520 in the controller 120, Fig. 5 in Fig. 2.Wherein, memory cell 521 is for the mode of operation of memory circuit proterctive equipment (such as electric motor car, electric tool) explicitly and early warning current reference value.Mode checking unit 522 can be coupled in power supply 200 and load 300, for testing pattern.In one example, mode checking unit in embodiment illustrated in fig. 5 522 and Fig. 3, embodiment illustrated in fig. 4 in the basic function of mode checking unit 123 similar, therefore not repeat them here.Over-current detection unit 523 can be coupled in memory cell 521 and mode checking unit 522, for detect according to mode checking unit 522 mode of operation, indicate and flow through via the first switch 510 the early warning current reference value stored in first signal of the electric current I of load 300 and memory cell 521 and judge whether to have occurred described exception.

Advantageously; embodiments of the invention can the different working modes of combined circuit proterctive equipment (such as electric motor car, electric tool) and the first signal of indicator current judge whether to have occurred described exception, thus further increase the precision judged circuit abnormality.

Fig. 6 shows the schematic diagram of an example of the over-current detection unit 523 in circuit protection device 500 shown in Fig. 5.As shown in Figure 6, over-current detection unit 523 comprises the second computing module 523a and the second judge module 523b.

Wherein, the second computing module 523a is coupled in mode checking unit 522 and memory cell 521, for the early warning current reference value be associated with the mode of operation that mode checking unit 522 detects that memory cell 521 stored as Second Threshold I _th.Second judge module 523b is coupled in the second computing module 523a, for comparing the first signal and the Second Threshold I of indicator current I _th, to judge whether to have occurred exception.In one embodiment, Second Threshold I is greater than at first signal of indicator current I _thwhen, the second judge module 523b is judged that there is described exception.

Advantageously; consider that the early warning electric current that electric circuit protection equipment (is such as in static condition, operating state etc.) under different working modes may be different; in an embodiment of the present invention the mode of operation of electric circuit protection equipment and corresponding early warning current reference value are stored explicitly; and according to current detection to the determined early warning electric current of mode of operation carry out abnormal judgement, can effectively improve thus circuit abnormality judge precision.

In a kind of possible execution mode, early warning electric current can be set according to the running current of electric circuit protection equipment under different working modes.Be that electric motor car illustrates with electric circuit protection equipment; under the first mode of operation that key switch disconnects and burglar alarm is not triggered; because electric motor car is in static condition, running current lower (such as usual at about 10mA), therefore can be set to 1A by early warning current reference value.Under the second mode of operation that key switch disconnects and burglar alarm is triggered, because burglar alarm needs to consume certain electric power, early warning current reference value, than large (such as usual at about 1A ~ 2A) under the first mode of operation, therefore can be set to 3A by the running current under this pattern.To close and under the 3rd mode of operation not having handle signal for faster at key switch, electric motor car is in state to be sailed, running current under this pattern is usually at 50-100mA, maximum operating currenbt such as opens headlight at 2-3A(, when direction indicator lamp), therefore early warning current reference value can be set to 5A.To close and under the 4th mode of operation having handle signal for faster, electric motor car is in transport condition at key switch, the running current under this pattern comparatively large (being such as usually less than 35A), therefore can be set to 40-50A by early warning current reference value.

In the execution mode that another kind is possible, can also under each mode of operation of electric circuit protection equipment, in conjunction with the factor of other influences operating current, such as different ambient temperatures etc., arranges different early warning electric currents.In the execution mode that another is possible, judgement time of delay for different early warning electric current can also be set further, when first signal of the indicator current I detected at least judges time of delay higher than this state continuance of the Second Threshold of instruction early warning electric current, just be judged as having occurred circuit abnormality, thus improve the precision of circuit abnormality judgement further.

Fig. 7 shows schematic diagram when being applied to according to the circuit protection device 700 of further embodiment of this invention the electric circuit protection equipment comprising power supply 200 and load 300.

As shown in Figure 7; in this embodiment; circuit protection device 700 comprises the first switch 710 and controller 720; and the major function of the first switch 710 and controller 720 is substantially similar with the major function of the first switch 110,510 in previous embodiment and controller 120,520 respectively, therefore does not repeat them here.

But by comparing known by Fig. 7 and Fig. 2, Fig. 5, controller 720 is with the essential difference of controller 120,520, and controller 720 comprises memory cell 721, mode checking unit 722, over-current detection unit 723 and load detecting unit 724.Wherein, memory cell 721 can be the combination of memory cell 121 in previous embodiment and memory cell 521, mode checking unit 722 is substantially similar with the major function of the mode checking unit 123,522 in previous embodiment, over-current detection unit 723 is substantially similar with the major function of the over-current detection unit 523 in previous embodiment, load detecting unit 724 is substantially similar with the major function of the load detecting unit 122 in previous embodiment, therefore does not repeat them here.

Advantageously; because the controller 720 in circuit protection device 700 comprises mode checking unit 722, over-current detection unit 723 and load detecting unit 724 simultaneously; being all carry out when considering mode of operation to make overcurrent protection and automatic recovery, control circui precision can being improved further.

Fig. 8 shows schematic diagram when being applied to according to the circuit protection device 800 of further embodiment of this invention the electric circuit protection equipment comprising power supply 200 and load 300.Composition graphs 1-7 is described by Fig. 8.

As shown in Figure 8, in this embodiment, electric circuit protection equipment comprises power supply 200, load 300 and circuit protection device 800.In one embodiment, power supply 200 battery pack that can be multiple serial battery and/or be connected in parallel and formed.In a kind of possible specific implementation, electric circuit protection equipment can be electric motor car, and power supply 200 can be the rechargeable battery of electric motor car.

Circuit protection device 800 comprises the first switch 810, controller 820, current detector (such as current sampling resistor R1) and current-limiting resistance (such as current-limiting resistance R2).Wherein, the first switch 810 is substantially similar with the major function of the first switch 110,510,710 in previous embodiment; The major function of controller 820 and controller 720 is substantially similar, therefore does not repeat them here.It will be appreciated by those skilled in the art that and the present invention is not limited thereto, controller 820 also can be similar with controller 120,520 etc.In one embodiment, the first switch 810 is metal oxide semiconductor field effect tube (MOSFET).

Wherein, current sampling resistor R1 is coupled in the first switch 810 and controller 820, is also coupled in power supply 200 or load 300, for detect flow through load 300 when the first switch 810 is connected electric current I to generate the first signal.In other words, the electric current on the performance loop that forms via the first switch 810 mainly for detection of power supply 200 and load 300 of current sampling resistor R1.In one embodiment, the voltage drop between the node a of first signal of the indicator current I voltage Vr1(that is current sampling resistor R1 two ends such as shown in Fig. 8 and node b); Correspondingly, the early warning current reference value that memory cell 821 prestores can be the magnitude of voltage at current sampling resistor R1 two ends when electric motor car normally works under different working modes.The early warning current reference value stored in first signal of the mode of operation that over-current detection unit 823 detects according to mode checking unit 822, indicator current I and memory cell 821 judges whether to have occurred circuit abnormality, and namely the early warning current reference value be associated with the mode of operation that mode checking unit 822 detects that memory cell 821 stored of over-current detection unit 823 is as Second Threshold I _th, and be greater than Second Threshold I at the first signal at indicator current I _thwhen, judge to occur extremely.Current-limiting resistance R2 is in parallel with the first switch 810, be mainly used in when the first switch 810 disconnects (performance loop that namely power supply 200 and load 300 are formed via the first switch 810 disconnects), form measure loop with power supply 200 and load 300, controller 820 can detect the 3rd signal of the secondary signal of the supply voltage Vb of instruction power supply 200 and the load voltage Vl of instruction load 300.In one embodiment, controller 800 obtains by the both end voltage of direct-detection power supply 200 secondary signal indicating supply voltage Vb, is obtained the 3rd signal of instruction load voltage V1 by the both end voltage detecting load 300.Correspondingly, first reference signal of the instruction supply voltage be associated with storing in memory cell 821 and the second reference signal of instruction load voltage are respectively the both end voltage of the power supply 200 be associated with electric motor car mode of operation under normal circumstances and the both end voltage of load 300, then load detecting unit 824 calculates first threshold V according to the first reference signal stored in secondary signal and memory cell 821 and the second reference signal _th, and be not less than first threshold V at the 3rd signal of instruction load voltage _thwhen, decision circuit is abnormal to be eliminated.

In another embodiment, (node shown in Fig. 8 a) can be set to ground connection to the negative terminal of power supply 200, controller 820 obtains the first signal of the electric current I in instruction performance loop by the terminal voltage (b of node shown in Fig. 8 place) detecting current sampling resistor R1, the secondary signal indicating supply voltage Vb is obtained in measure loop by the positive terminal voltage (the node d place shown in Fig. 8) of power supply 200, and the voltage of the one end (the node c place shown in Fig. 8) to be coupled by detectability leakage resistance R2 and load 300 obtains in measure loop the 3rd signal indicating load voltage V1.Correspondingly, the early warning current reference value that memory cell 821 prestores can be the terminal voltage of current sampling resistor R1 when electric motor car normally works under different working modes; The first reference signal that what memory cell 821 prestored be associated and the second reference signal can be respectively the voltage of one end that the positive terminal voltage of the power supply 200 be associated with electric motor car mode of operation under normal circumstances, current-limiting resistance R2 and load 300 are coupled.In this embodiment, load detecting unit 824 calculates first threshold V according to the first reference signal stored in secondary signal and memory cell 821 and the second reference signal _th, and be not more than first threshold V at the 3rd signal of instruction load voltage _thwhen, decision circuit is abnormal to be eliminated.

In addition, because current-limiting resistance R2 is mainly used in reducing the electric current in measure loop, to avoid detecting secondary signal and the 3rd signal to judge to cause device failure in the abnormal process whether eliminated, the resistance of current-limiting resistance R2 can be preferably larger value, such as hundreds of Europe, even goes up kilo-ohm.

It should be noted that, although carry out the first reference signal of at least one group of instruction supply voltage and the second reference signal of instruction load voltage being explicitly stored as example with memory cell 121,521,721 to describe principle that abnormal load detects as above, and the first reference signal using the both end voltage of power supply 200 under normal circumstances as instruction supply voltage in example, the second reference signal using the both end voltage of load 300 under normal circumstances as instruction load voltage.But, those skilled in the art will be understood that, current-limiting resistance R2 is being set as shown in Figure 8 to contribute in the implementation of secondary signal and the 3rd input, memory cell 121, 521, at least one group of 721 associated storage indicates the first reference signal of supply voltage with the second reference signal of instruction load voltage, first reference signal also can be the positive terminal voltage of power supply 200 under normal circumstances, second reference signal of instruction load voltage also can be the voltage of one end that current-limiting resistance R2 and load 300 are under normal circumstances coupled, and judge abnormal whether elimination as follows.Such as, the negativing ending grounding of power supply 200, controller 800 obtains the secondary signal of instruction supply voltage Vb by detecting the positive terminal voltage of power supply 200, and the voltage of the one end be coupled by detectability leakage resistance R2 and load 300 is obtained and indicates the 3rd signal of load voltage V1 (i.e. in fact the both end voltage of load 300 can deduct the voltage difference of the 3rd signal for secondary signal).Then, above-mentioned first reference signal that controller 800 stores according to above-mentioned secondary signal, memory cell 821 and above-mentioned second reference signal, calculate the load voltage reference value that is associated with above-mentioned secondary signal using as first threshold.Further, in this embodiment, when indicating the 3rd signal of load voltage to be not more than first threshold, judge that described exception is eliminated.

As shown in Figure 8, in a kind of possible execution mode, circuit protection device 800 also can comprise second switch 830, and second switch 830 is connected with current-limiting resistance R2, is mainly used in avoiding current-limiting resistance R2 to have influence on performance loop.Further, second switch 830 is the same with the first switch 810 is also controlled to be switched on or switched off by controller 820.

In a kind of possible embodiment, such as, controller 820 makes that the first switch 810 is closed, second switch 830 disconnects in normal state, is formed performance loop to make power supply 200, load 300 and current sampling resistor R1 via the first switch 810.When detecting that when the first switch 810 is connected the electric current I flowing through load 300 is greater than early warning electric current (judging to occur extremely by the first signal and early warning current reference value that compare indicator current I), controller 810 makes the first switch 810 disconnect performance loop, make second switch 830 connect simultaneously, formed measure loop to make power supply 200, load 300 and current-limiting resistance R2 via second switch 830.After this, when judging that abnormal load is eliminated (namely load 300 recovers normal) according to the secondary signal of the instruction supply voltage Vb utilized detected by measure loop and the 3rd signal of instruction load voltage Vl, controller 810 makes second switch 830 disconnect with disconnection detection loop, make the first switch 830 connect simultaneously, again formed performance loop via the first switch 810 to make power supply 200, load 300 and current sampling resistor R1.Whether in one embodiment, if controller 810 judges that above-mentioned exception is not eliminated, controller 810 can periodically connect second switch 830, eliminate periodically to detect above-mentioned exception.

Fig. 9 shows a kind of according to an embodiment of the invention indicative flowchart of circuit protection method, and circuit structure shown in composition graphs 1-8 is described by Fig. 9.Although Fig. 9 discloses some specific step, these steps are as just example, and the present invention is equally applicable to distortion or other steps of step shown in Fig. 9.

As shown in Figure 9, in this embodiment, this circuit protection method comprises:

Step 901, when being coupled in load (such as load 300) and connecting for the first switch (such as the first switch 110,510,710,810) between the power supply (such as power supply 200) for load supplying, controller (such as controller 120,520,720,820) detects the first signal flowing through the electric current of load;

Step 902, controller judges whether to have occurred exception according to the first signal, and performs step 903 when being judged that there is abnormal, otherwise returns step 901;

Step 903, controller disconnects the first switch;

Step 904, when by performing step 903 and making the first switch disconnect, controller detects the secondary signal of the supply voltage of instruction power supply 200 and the 3rd signal of load voltage of instruction load 300;

Step 905, controller 120 judges abnormal whether elimination according to secondary signal and the 3rd signal, and performs step 906 when judgement is eliminated extremely, otherwise returns step 904; And

Step 906, the first switch 110 connected by controller 120.

In this embodiment, when judging abnormal elimination, automatically connecting the first switch as overcurrent protective switch, achieving recovering in time voluntarily of circuit.In addition, because this recovery carries out when judging abnormal elimination, therefore there is potential safety hazard hardly.

In a kind of possible execution mode, if judge extremely not eliminate in step 905, step 904 can be returned immediately and continue to detect.In the embodiment that another kind is possible, also when the first switch disconnects, step 904 can be performed with the fixing cycle, and when being judged as abnormal elimination in step 905, stop performing step 904.

Figure 10 shows the indicative flowchart of a kind of possibility execution mode of step 905 shown in Fig. 9, and is described by controller 120 shown in step and Fig. 2 shown in composition graphs 9.

As shown in Figure 10, in this embodiment, step 905 can specifically comprise:

Step 9051, the first computing module 122a in load detecting unit 122, according to the second reference signal of the first reference signal of at least one group of the memory cell 121 pre-stored instruction supply voltage be associated and instruction load voltage, calculates with the load voltage reference value indicating the secondary signal of supply voltage to be associated using as first threshold V _th; And

Step 9052, the first judge module 122b in load detecting unit 122 compares the 3rd signal and first threshold V of instruction load voltage _th, to judge whether above-mentioned exception is eliminated.

Figure 11 shows the flow chart of circuit protection method according to another embodiment of the present invention, and is described by controller 120 shown in composition graphs 3.

As shown in figure 11, in this embodiment, step 1110 ~ 1104 and step 1107 respectively with embodiment illustrated in fig. 9 in step 901 ~ 904 and step 906 function class seemingly, therefore not repeat them here.

As shown in figure 11, the present embodiment and the main distinction embodiment illustrated in fig. 9 are, before execution step 1106, mode checking unit 123 in controller 120 also can be utilized to perform step 1105, with the mode of operation of testing circuit proterctive equipment (such as electric motor car).In addition, although in fig. 11, perform after step 1105 being placed on step 1104, but what it will be understood by those skilled in the art that is, as long as step 1105 is before step 1106 performs, user can according to the execution sequence of application scenarios or the flexible setting procedure of actual needs 1105 and step 1110 ~ 1104.

Figure 12 shows the indicative flowchart of a kind of possibility execution mode of step 1105 shown in Figure 11, and will be described in conjunction with mode checking unit 123 shown in step and Fig. 4 shown in Figure 11.In this embodiment, electric circuit protection equipment is electric motor car.

As shown in figure 12, step 1105 can specifically comprise:

Whether the key switch that step 1105a, key detection module 123a detect electric motor car closes, and detects that key switch performs step 1105e closed, otherwise perform step 1105b at key detection module 123a;

Step 1105b, whether the burglar alarm that antitheft detection module 123b detects electric motor car is triggered, and performs step 1105d when antitheft detection module 123b detects that burglar alarm is triggered, otherwise performs step 1105c;

Step 1105c, mode decision module 123d judge that electric motor car is in the first mode of operation;

Step 1105d, mode decision module 123d judge that electric motor car is in the second mode of operation;

Step 1105e, handle acceleration detection module 123c detect whether there is handle signal for faster, perform step 1105g when handle acceleration detection module 123c has detected handle signal for faster, otherwise perform step 1105f;

Step 1105f, mode decision module 123d judge that electric motor car is in the 3rd mode of operation;

Step 1105g, mode decision module 123d judge that electric motor car is in the 4th mode of operation.

Although in order to be described clearly, illustrate in Figure 12 and first having performed step 1105a, perform step 1105b, step 1105e again, but also first can perform step 1105b, perform step 1105a, step 1105e again.Only exemplarily, that is the present invention is also applicable to the step that performs other rational steps or improve Figure 12 to the concrete steps that Figure 12 is contained.

In one example, when mode decision module 123d judges that electric motor car is in the 3rd mode of operation or the 4th mode of operation, namely, under judging that electric motor car is in state to be sailed or transport condition, controller 120 does not perform step 1106, to guarantee traffic safety as far as possible.

Figure 13 shows an example of step 1106 in the embodiment shown in Figure 11, and is described in conjunction with the load detecting unit 122 in controller 120 shown in step shown in Figure 11 and Fig. 3.

As shown in figure 13, step 1106 can specifically comprise:

Step 1106a, the first computing module 122a in load detecting unit 122, according to the first reference signal of the instruction supply voltage be associated with detected mode of operation of memory cell 121 pre-stored and the second reference signal indicating load voltage, calculates with the load voltage reference value indicating the secondary signal of supply voltage to be associated using as first threshold V _th; And

Step 1106b, the first judge module 122b in load detecting unit 122 are by comparing the 3rd signal of instruction load voltage and above-mentioned first threshold V _th, to judge whether above-mentioned exception is eliminated.In one embodiment, the first judge module 122b is not less than first threshold V at the 3rd signal of instruction load voltage _thwhen, judge that described exception is eliminated.

Figure 14 shows the indicative flowchart of a kind of circuit protection method according to further embodiment of this invention, and is described by controller 520 shown in step and Fig. 5 shown in composition graphs 9.Although Figure 14 discloses some specific step, these steps are as just example, and the present invention is equally applicable to distortion or other steps of step shown in Figure 14.

As shown in figure 14, in this embodiment, step 1401, step 1403 ~ 1404 and step 1406 respectively with the step 901 in the embodiment shown in Fig. 9, step 903 ~ 904 and step 906 function class seemingly, therefore not repeat them here.

As shown in figure 14, the main distinction of the present embodiment and Fig. 9 embodiment is, controller 520 shown in Fig. 5 can be utilized to perform step 1402, and namely step 1402 can specifically comprise:

Step 1402a, the mode checking unit 522 in controller 520 detects the mode of operation of the electric motor car as load 300; And

Step 1402b, the over-current detection unit 522 in controller 520 judges whether to have occurred described exception according to detected mode of operation and the first signal.

Wherein, step 1402a and step 1105 function class seemingly, therefore do not repeat them here.

Figure 15 shows a kind of possible execution mode of step 1402b shown in Figure 14, and will be described in conjunction with controller 520 shown in step and Fig. 6 shown in Figure 14.

As shown in figure 15, step 1402b can specifically comprise:

The early warning current reference value be associated with the mode of operation detected by mode checking unit 522 of pre-stored in memory cell 521 is determined as Second Threshold I by step 1402b_1, the second computing module 523a in over-current detection unit 523 _th; And

Step 1402b_2, over-current detection unit 523 is by comparing the first signal and the Second Threshold I of indicator current I _th, to judge whether to occur described exception.In one embodiment, Second Threshold I is greater than at the electric current of the first signal designation _thwhen, the second judge module 523b in over-current detection unit 523 is judged that there is described exception.

In addition, owing to performing step 1402a before, the step 1405 in the embodiment shown in Figure 14 can specifically comprise the step 1106a shown in Figure 13 and step 1106b.

Those of ordinary skill in the art can recognize, each exemplary cell in embodiment described herein and algorithm steps, can realize with the combination of electronic hardware or computer software and electronic hardware.These functions realize with hardware or software form actually, depend on application-specific and the design constraint of technical scheme.Professional and technical personnel can realize described function for specific application choice diverse ways, but this realization should not thought and exceeds scope of the present invention.

If using the form of computer software realize described function and as independently production marketing or use time, then can think that all or part of (such as to the part that prior art contributes) of technical scheme of the present invention embodies in form of a computer software product to a certain extent.This computer software product is stored in the storage medium of embodied on computer readable usually, comprises all or part of step of some instructions in order to make computer equipment (can be personal computer, server or the network equipment etc.) perform various embodiments of the present invention method.And aforesaid storage medium comprise USB flash disk, portable hard drive, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random AccessMemory), magnetic disc or CD etc. various can be program code stored medium.

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; change can be expected easily or replace, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should described be as the criterion with the protection range of claim.

Claims

1. a circuit protection device, is characterized in that, described circuit protection device comprises:

First switch, is coupled in load and between the power supply for described load supplying; And

Controller, is coupled in described first switch, described load and described power supply, for

When judging to occur abnormal according to the first signal, disconnecting described first switch, described in wherein said first signal designation, during the first switch connection, flowing through the electric current of described load, and

When described first switch disconnects, when judging that described exception is eliminated according to secondary signal and the 3rd signal, connect described first switch, wherein said secondary signal indicates the supply voltage of described power supply, the load voltage of load described in described 3rd signal designation.

2. circuit protection device according to claim 1, is characterized in that, described controller comprises:

Memory cell, indicates the first reference signal of described supply voltage and the second reference signal indicating described load voltage for storing at least one group explicitly; And

Load detecting unit, is coupled in described memory cell, for judging whether described exception is eliminated according to described first reference signal stored in described secondary signal, described 3rd signal and described memory cell and described second reference signal.

3. circuit protection device according to claim 2, is characterized in that, described load detecting unit comprises:

First computing module, is coupled in described memory cell, for according to described secondary signal, described first reference signal and described second reference signal, calculates the load voltage reference value that is associated with described secondary signal using as first threshold; And

First judge module, is coupled in described first computing module, for comparing described 3rd signal of the described load voltage of instruction and described first threshold, to judge whether described exception is eliminated.

4. circuit protection device according to claim 1, is characterized in that, described controller comprises:

Mode checking unit, described mode checking unit is coupled in described power supply and described load, for testing pattern;

Memory cell, is coupled in described mode checking unit, for store described mode of operation explicitly and at least one group indicate the first reference signal of described supply voltage and indicate the second reference signal of described load voltage; And

Load detecting unit, be coupled in described mode checking unit and described memory cell, for judging whether described exception is eliminated according to described first reference signal be associated with the mode of operation that described mode checking unit detects of described secondary signal, described 3rd signal, described cell stores and described second reference signal.

5. circuit protection device according to claim 4, is characterized in that, described controller also comprises over-current detection unit, wherein

Described memory cell is also for storing described mode of operation and early warning current reference value explicitly; And

Described over-current detection unit is coupled in described mode checking unit and described memory cell, judges whether to occur described exception for the described early warning current reference value stored in the mode of operation detected according to described mode checking unit, described first signal and described memory cell.

6. circuit protection device according to claim 1, is characterized in that, described controller comprises:

Mode checking unit, is coupled in described power supply and described load, for testing pattern;

Memory cell, is coupled in mode checking unit, for storing described mode of operation and early warning current reference value explicitly; And

Over-current detection unit, be coupled in described mode checking unit and described memory cell, judge whether to occur described exception for the described early warning current reference value stored in the mode of operation detected according to described mode checking unit, described first signal and described memory cell.

7. the circuit protection device according to claim 5 or 6, is characterized in that, described over-current detection unit comprises:

Second computing module, is coupled in described mode checking unit and described memory cell, for using the early warning current reference value be associated with the mode of operation that described mode checking unit detects of described cell stores as Second Threshold; And

Second judge module, is coupled in described second computing module, for more described first signal and described Second Threshold, to judge whether to occur described exception.

8. circuit protection device according to any one of claim 1 to 6, is characterized in that, described circuit protection device also comprises:

Current detector, is coupled in described first switch, described load and described controller, flows through the electric current of described load to generate described first signal during for detecting described first switch connection.

9. circuit protection device according to claim 8, is characterized in that, described circuit protection device also comprises:

Current-limiting resistance, is connected with described first switch in parallel; And

Second switch, is connected in series with described current-limiting resistance, connects, and disconnect when described first switch connection when described first switch disconnects.

10. a circuit protection method, is characterized in that, described circuit protection method comprises:

When being coupled in load and for the first switch connection between the power supply for described load supplying, detect the first signal that instruction flows through the electric current of described load;

Judge whether to have occurred exception according to described first signal, and disconnect described first switch when being judged that there is abnormal;

When described first switch disconnects, detect the 3rd signal of the secondary signal of the supply voltage of the described power supply of instruction and the load voltage of the described load of instruction; And

Judge whether described exception is eliminated according to described secondary signal and described 3rd signal, and connect described first switch when judging that described exception is eliminated.

11. circuit protection methods according to claim 10, is characterized in that, judge that the step whether described exception has been eliminated comprises according to described secondary signal and described 3rd signal:

According to the first reference signal of at least one group of described supply voltage of the instruction be associated of described secondary signal, pre-stored and the second reference signal indicating described load voltage, calculate the load voltage reference value that is associated with described secondary signal using as first threshold; And

More described 3rd signal and described first threshold, to judge whether described exception is eliminated.

12. circuit protection methods according to claim 10, is characterized in that, before judging according to described secondary signal and described 3rd signal the step whether described exception has been eliminated, described circuit protection method also comprises:

Testing pattern, and

Judge that the step whether described exception has been eliminated comprises according to described secondary signal and described 3rd signal:

According to the first reference signal of the described supply voltage of instruction be associated with detected mode of operation of described secondary signal, pre-stored and the second reference signal indicating described load voltage, calculate the load voltage reference value that is associated with described secondary signal using as first threshold; And

13. circuit protection methods according to claim 12, is characterized in that, the step detecting described mode of operation comprises:

When key switch disconnection being detected and burglar alarm is not triggered, judge to be in the first mode of operation;

When the disconnection of described key switch being detected and described burglar alarm is triggered, judge to be in the second mode of operation;

When detecting that described key switch closes and do not have handle signal for faster, judge to be in the 3rd mode of operation; And

When detecting that described key switch closes and has described handle signal for faster, judge to be in the 4th mode of operation.

14. circuit protection methods according to claim 13; it is characterized in that; when judging to be in described 3rd mode of operation or described 4th mode of operation, not performing and judging according to described secondary signal and described 3rd signal the step whether described exception has been eliminated.

15. circuit protection methods according to claim 10, is characterized in that, judge whether to have occurred that abnormal step comprises according to described first signal:

Testing pattern; And

Judge whether to have occurred described exception according to detected mode of operation and described first signal.

16. circuit protection methods according to claim 15, is characterized in that, judge whether to have occurred that described abnormal step comprises according to detected mode of operation and described first signal:

The early warning current reference value be associated with detected described mode of operation of pre-stored is determined as Second Threshold; And

More described first signal and described Second Threshold, to judge whether to occur described exception.

17. 1 kinds of electric circuit protection equipments, is characterized in that, described electric circuit protection equipment comprises power supply, load and is coupled in the circuit protection device of described power supply and described load, and wherein said circuit protection device comprises:

18. electric circuit protection equipments according to claim 17, is characterized in that, described controller comprises:

Mode checking unit, described mode checking unit is coupled in described power supply and described load, for detecting the mode of operation of described electric circuit protection equipment;

Memory cell, is coupled in described mode checking unit, and mode of operation and at least one group for storing described electric circuit protection equipment explicitly indicate the first reference signal of described supply voltage and indicate the second reference signal of described load voltage; And

19. electric circuit protection equipments according to claim 18, is characterized in that, described controller also comprises over-current detection unit,

Described memory cell is also for storing mode of operation and the early warning current reference value of described electric circuit protection equipment explicitly; And

20. electric circuit protection equipments according to claim 17, is characterized in that, described controller comprises:

Mode checking unit, is coupled in described power supply and described load, for detecting the mode of operation of described electric circuit protection equipment;

Memory cell, is coupled in mode checking unit, for storing mode of operation and the early warning current reference value of described electric circuit protection equipment explicitly; And

21. according to the electric circuit protection equipment of claim 18-20 described in one of them, and it is characterized in that, described electric circuit protection equipment is electric motor car, and described mode checking unit comprises:

Whether key detection module, close for the key switch detecting described electric motor car;

Whether antitheft detection module, be triggered for the burglar alarm detecting described electric motor car;

Whether handle acceleration detection module, have handle signal for faster for detecting described electric motor car; And

Mode decision module, is coupled in described key detection module, described antitheft detection module and described handle acceleration detection module, for

When the disconnection of described key switch being detected and described burglar alarm is not triggered, judge that described electric motor car is in the first mode of operation;

When the disconnection of described key switch being detected and described burglar alarm is triggered, judge that described electric motor car is in the second mode of operation;

When detecting that described key switch closes and do not have described handle signal for faster, judge that described electric motor car is in the 3rd mode of operation; And

When detecting that described key switch closes and has described handle signal for faster, judge that described electric motor car is in the 4th mode of operation.

22. electric circuit protection equipments according to claim 21, is characterized in that, when described mode checking unit judges that described electric motor car is in described 3rd mode of operation or described 4th mode of operation, described controller forbids described load detecting unit.

23. electric circuit protection equipments according to claim 17, is characterized in that, described electric circuit protection equipment is electric motor car or electric tool.