CN101964511B - Overcurrent protection circuit and television - Google Patents
Overcurrent protection circuit and television Download PDFInfo
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- CN101964511B CN101964511B CN 201010270418 CN201010270418A CN101964511B CN 101964511 B CN101964511 B CN 101964511B CN 201010270418 CN201010270418 CN 201010270418 CN 201010270418 A CN201010270418 A CN 201010270418A CN 101964511 B CN101964511 B CN 101964511B
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Abstract
The embodiment of the invention provides an overcurrent protection circuit and a television, relating to the technical field of electronics and solving the technical problem that LED lamp bars are easy to damage due to an overcurrent phenomenon since the traditional protection circuit in the television can not emit a driving signal before the LED lamp bars are damaged due to the overcurrent phenomenon. The overcurrent protection circuit comprises a current induction module, a first input end, a second input end and a first output end, wherein the first input end, the second input end and the first output end are connected with the current induction module; and when currents flowing through the first input end and the second input end exceed a first preset value, the current induction module outputs a first driving signal through the first output end. The television comprises a driving chip, a power consumption device, a boosted circuit and the overcurrent protection circuit provided by the embodiment. The invention is applied to carrying out overcurrent protection on the power consumption device in the circuit.
Description
Technical field
The present invention relates to electronic technology field, the television set that is specifically related to a kind of circuit overcurrent protection and is provided with this circuit overcurrent protection.
Background technology
Along with the develop rapidly of electronic technology and television technologies, television set has become one of household electrical appliance the most common in the daily life.
Usually be provided with multiple power consumption device in the television set, for example: be provided with LED (Light Emitting Diode in the liquid crystal display screen of existing liquid crystal TV set usually, light-emitting diode) lamp bar can provide backlight when LED lamp bar is luminous for the liquid crystal panel of liquid crystal display screen.
As shown in Figure 1, existing television set comprises power management chip 6, chip for driving 3, power supply 4, booster circuit 5, LED lamp bar 9 and protective circuit, and protective circuit comprises overpower protection circuit 7 and excess voltage protection 8, wherein:
The needed electric energy of LED lamp bar 9 work is boosted to importing LED lamp bar 9 by the electric energy output end of booster circuit 5 after the rated operational voltage of LED lamp bar 9 through booster circuit 5 by power supply 4 outputs again;
Whether chip for driving 3 is used to control booster circuit 5 and the electric energy of power supply 4 outputs is boosted, and the input of the electric energy after will boosting LED lamp bar 9;
Excess voltage protection 8 links to each other with chip for driving 3, whether the voltage that excess voltage protection 8 is used to detect the electric energy output end input LED lamp bar 9 of booster circuit 5 surpasses predetermined value, when the voltage of the electric energy output end of booster circuit 5 surpasses predetermined value, excess voltage protection 8 can be exported first drive signal, and with first drive signal input chip for driving 3;
When 8 pairs of chip for driving of excess voltage protection, 3 inputs, first drive signal, chip for driving 3 enters lock-out state, when chip for driving 3 enters lock-out state, the electric energy output end of booster circuit 5 can stop to export electric energy, chip for driving 3 enters after the lock-out state, after the needs operation manually powered on to chip for driving 3 again, chip for driving 3 just can withdraw from lock-out state, started once more;
Overpower protection circuit 7 links to each other with power management chip 6, whether the power that overpower protection circuit 7 is used to detect LED lamp bar 9 (for example: rated power) surpasses predetermined value, when the power of LED lamp bar 9 surpasses predetermined value, overpower protection circuit 7 can be exported second drive signal, and with the voltage of second drive signal input power management chip, 6, the second drive signals usually above first drive signal;
When having served as 7 pairs of power management chips of power protecting circuit, 6 inputs, second drive signal; power management chip 6 enters frequency hopping state (the frequency hopping state is restarted once after being meant one section preset time of street automatically); when power management chip 6 enters the frequency hopping state; power supply 4 can stop to export electric energy; when not having the input of second drive signal; power management chip 6 withdraws from the frequency hopping state, and when power management chip 6 withdrawed from the frequency hopping state, power supply 4 can be exported electric energy again.
In realizing process of the present invention, the inventor finds that there are the following problems at least in the prior art:
Protective circuit in the existing television set, though can realize to a certain extent to the overpower protection or the overvoltage protection of LED lamp bar 9 as shown in Figure 1, but in production, assembling and the use of LED lamp bar 9, overpower or superpotential problem not only may appear in LED lamp bar 9, and overcurrent over the ground or short circuit very easily occur and cause LED lamp bar 9 that the situation of overcurrent takes place, when overcurrent or short-circuit conditions occurring over the ground, big electric current (this electric current is called as overcurrent) can occur and LED lamp bar 9 be burnt, cause LED lamp bar 9 to damage through LED lamp bar 9;
But; when big electric current passes through LED lamp bar 9; protective circuit in the existing television set is that excess voltage protection 8 and circuit overcurrent protection do not have the function of sending drive signal in LED lamp bar 9 generation overcurrent phenomenons before damaging; so LED lamp bar 9 easily damages because of the overcurrent phenomenon; when serious, the fail safe that overcurrent over the ground that LED lamp bar 9 takes place or short circuit phenomenon also can influence whole television set.
Summary of the invention
The embodiment of the invention provides a kind of circuit overcurrent protection on the one hand; a kind of television set that is provided with this circuit overcurrent protection also is provided on the other hand; the protective circuit that has solved in the existing television set can't be sent drive signal in LED lamp bar generation overcurrent phenomenon before damaging, and then the technical problem that causes LED lamp bar easily to damage because of the overcurrent phenomenon.
For achieving the above object, embodiments of the invention adopt following technical scheme:
This circuit overcurrent protection comprises induction by current module and the first input end that links to each other with described induction by current module, second input and first output, wherein:
When the electric current that flows through described first input end and described second input surpassed first predetermined value, described induction by current module was exported first drive signal by described first output.
Compared with prior art, the technique scheme that provided of embodiment of the invention circuit overcurrent protection can produce following technique effect at least:
Because in the circuit overcurrent protection that the embodiment of the invention provided, when the electric current that flows through the first input end and second input surpasses first predetermined value, the induction by current module can be exported first drive signal by first output, this shows, if with first input end and second input be connected in the power consumption device (for example: the LED lamp bar in the television set) and the electric energy output end of powering for the power consumption device (for example: in the time of the electric energy output end of television set booster circuit), the induction by current module can be passed through the first input end and the second input collection, and then identification flows through the current value for the electric current of the electric energy output end of power consumption device power supply and power consumption device, thereby judges the phenomenon that whether has overcurrent on the power consumption device;
Simultaneously; because the induction by current module also can be when the electric current that flows through the first input end and second input surpasses first predetermined value; export first drive signal; promptly the state that whether has the overcurrent phenomenon on the power consumption device form with drive signal can also be sent by first output; so in actual production; operating personnel can be redefined for first predetermined value lowest high-current value that power consumption device operate as normal can bear; like this; when overcurrent or short circuit take place over the ground and cause the phenomenon of overcurrent takes place in the power consumption device; the induction by current module can be in power consumption device generation overcurrent phenomenons such as LED lamp bars and before damaging; the state of the power consumption device generation overcurrent phenomenon form with drive signal is sent by first output, so solved protective circuit in the existing television set can't be sent drive signal in LED lamp bar generation overcurrent phenomenon before damaging technical problem.
Further, described first input end and described second input link to each other with the electric energy output end of the described electric current of output successively along the direction of described current delivery respectively;
Described induction by current module comprises first resistance, second resistance and a PNP triode, wherein:
Described first resistance is connected between described first input end and described second input;
The emitter of a described PNP triode links to each other with described first input end, the base stage of a described PNP triode links to each other with described second input, and the collector electrode of a described PNP triode links to each other with described second resistance of described first output and ground connection respectively.
Further, described induction by current module also comprises first electric capacity and first diode, wherein:
The two poles of the earth of described first electric capacity link to each other with described first input end and described second input respectively;
The positive pole of described first diode links to each other with the collector electrode of a described PNP triode, described second resistance respectively, and the negative pole of described first diode links to each other with described first output.
Further, described induction by current module also comprises the 3rd resistance, and described the 3rd resistance is connected between the collector electrode and described first output of a described PNP triode.
Further, described induction by current module also comprises the 4th resistance and the 5th resistance, wherein:
Described the 4th resistance is connected between the negative pole of described electric energy output end and described first diode;
The negative pole of described first diode links to each other with described the 5th resistance and described first output of described the 4th resistance, ground connection respectively.
Further, this circuit overcurrent protection also comprises isolation boosting module and second output that links to each other with described isolation boosting module, wherein:
Described isolation boosting module links to each other with described first output, described isolation boosting module is used for being higher than second drive signal of described first drive signal by the described second output output voltage values when receiving described first drive signal of described first output output.
Further, described isolation boosting module comprises drawing on NPN triode, the optical coupler, first draws power supply and the 2nd PNP triode on the power supply, second, wherein:
The base stage of described NPN triode links to each other with described first output, the grounded emitter of described NPN triode, and the collector electrode of described NPN triode links to each other with the negative pole of photophore in the described optical coupler;
Draw power supply to link to each other on the positive pole and described first of photophore in the described optical coupler, in the described optical coupler positive pole of light-receiving device respectively with described second on draw the base stage of power supply and described the 2nd PNP triode to link to each other, the minus earth of the interior light-receiving device of described optical coupler;
Draw power supply to link to each other on the emitter of described the 2nd PNP triode and described second, the collector electrode of described the 2nd PNP triode links to each other with described second output.
Further, described isolation boosting module also comprises the 6th resistance, voltage stabilizing didoe and/or second diode of ground connection, wherein:
The collector electrode of described the 2nd PNP triode links to each other with described second output and described the 6th resistance respectively;
The positive pole of described voltage stabilizing didoe links to each other with the positive pole of light-receiving device in the described optical coupler, the negative pole of described voltage stabilizing didoe respectively with described second on draw the base stage of power supply, described the 2nd PNP triode to link to each other;
The positive pole of described second diode links to each other with the collector electrode of described the 2nd PNP triode, and the negative pole of described second diode links to each other with described second output, described the 6th resistance respectively.
Further, described isolation boosting module also comprises the 7th resistance, the 8th resistance and the 9th resistance, wherein:
Described the 7th resistance is connected between the emitter that draws power supply and described the 2nd PNP triode on described second;
Described the 8th resistance is connected between the base stage of the negative pole that draws power supply and described voltage stabilizing didoe on described second, described the 2nd PNP triode;
Described the 9th resistance is connected between the base stage of described the 2nd PNP triode and the negative pole of described voltage stabilizing didoe, described the 8th resistance;
The resistance of described the 9th resistance is greater than described the 7th resistance, and the resistance of described the 7th resistance is greater than described the 8th resistance.
This television set comprises the circuit overcurrent protection that chip for driving, booster circuit, power consumption device and the invention described above embodiment are provided, wherein:
The described first input end of described circuit overcurrent protection and described second input are connected between the electric energy output end and described power consumption device of described booster circuit;
Described chip for driving links to each other with described first output and described booster circuit respectively;
When described first output was imported described first drive signal to described chip for driving, described chip for driving entered lock-out state.
Further, isolation boosting module in the circuit overcurrent protection that this television set also comprises power supply, power management chip, the invention described above embodiment and provided and second output that links to each other with described isolation boosting module, wherein:
Described first input end and described second input link to each other with the electric energy output end of described power supply respectively;
Described isolation boosting module links to each other with described first output, described isolation boosting module is used for being higher than second drive signal of described first drive signal by the described second output output voltage values when receiving described first drive signal of described first output output;
Described power management chip links to each other with described second output and described power supply respectively;
When described second output is imported described second drive signal to described power management chip, described power management chip enters the frequency hopping state, when no described second drive signal was imported described power management chip, described power management chip withdrawed from the frequency hopping state.
Compared with prior art, the technique scheme that provided of embodiment of the invention television set can produce following technique effect at least:
Because the television set that the embodiment of the invention provided comprises the circuit overcurrent protection that the invention described above embodiment is provided, so the television set that the embodiment of the invention provided has identical technical characterictic with the circuit overcurrent protection that the invention described above embodiment is provided, so not only can obtain identical technique effect, and can solve identical technical problem;
When the circuit overcurrent protection that the invention described above embodiment is provided is applied to protect power consumption device on the television set, for example: during LED lamp bar, if operating personnel are redefined for lowest high-current value that the LED lamp bar operate as normal that electric energy output end connected of booster circuit can bear (certainly with first predetermined value, first predetermined value also can be worth less than this), between the electric energy output end and power consumption device that the first input end and described second input of circuit overcurrent protection is connected in booster circuit, simultaneously chip for driving is linked to each other with first output and the booster circuit of circuit overcurrent protection then;
When the electric current that flows through booster circuit electric energy output end and power consumption device surpasses the lowest high-current value that LED lamp bar operate as normal can bear; first output can be imported first drive signal to chip for driving; at this moment; chip for driving can enter lock-out state; and when chip for driving enters lock-out state; be subjected to the electric energy output end of the booster circuit of chip for driving control can stop to export electric energy; and then the electric current that can prevent to surpass the lowest high-current value that LED lamp bar operate as normal can bear causes damage to LED lamp bar; so the protective circuit that has solved in the existing television set can't be sent drive signal in LED lamp bar generation overcurrent phenomenon before damaging, and then the technical problem that causes LED lamp bar easily to damage because of the overcurrent phenomenon.
Description of drawings
In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.
Fig. 1 is the protective circuit of LED lamp bar in the existing television set and is the schematic diagram of the annexation of the critical piece of the circuit of LED lamp bar power supply;
Fig. 2 is the annexation schematic diagram of each parts in the circuit overcurrent protection that a kind of execution mode provided of the embodiment of the invention;
Fig. 3 is a kind of concrete enforcement circuit diagram of circuit overcurrent protection shown in Figure 2;
Fig. 4 is another concrete circuit diagram of implementing of circuit overcurrent protection shown in Figure 2;
Fig. 5 is the annexation schematic diagram of each parts in the circuit overcurrent protection that another execution mode provided of the embodiment of the invention;
Fig. 6 is the concrete enforcement circuit diagram of circuit overcurrent protection shown in Figure 5;
Fig. 7 for the circuit overcurrent protection in the television set that a kind of execution mode provided of the embodiment of the invention and with critical piece that circuit overcurrent protection links to each other between the schematic diagram of annexation;
Fig. 8 is the schematic diagram of each pin of chip for driving shown in Figure 7;
When Fig. 9 is applied to protect in the television set power consumption device for chip for driving shown in Figure 8, during power consumption device operate as normal and during power consumption device generation overcurrent, the wave form varies schematic diagram of voltage on the OUT pin of chip for driving and the OV pin;
Figure 10 for the circuit overcurrent protection in the television set that another execution mode provided of the embodiment of the invention and with critical piece that circuit overcurrent protection links to each other between the schematic diagram of annexation;
Figure 11 is the schematic diagram of each pin of power management chip shown in Figure 10;
When Figure 12 is applied to protect in the television set power consumption device for power management chip shown in Figure 11, during power consumption device operate as normal and during power consumption device generation overcurrent, the wave form varies schematic diagram of voltage on the MUPPER_6 pin of power management chip and the FB pin;
Figure 13 for the circuit overcurrent protection in the television set that another execution mode provided of the embodiment of the invention and with critical piece that circuit overcurrent protection links to each other between the schematic diagram of annexation.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, the every other embodiment that those of ordinary skills are obtained under the prerequisite of not paying creative work belongs to the scope of protection of the invention.
It is a kind of simple in structure, with low cost that the embodiment of the invention provides, and when being applied to protect LED lamp bar, circuit overcurrent protection and a kind of television set that is provided with this circuit overcurrent protection that can avoid LED lamp bar to damage because of the overcurrent phenomenon.
As shown in Figure 2, the circuit overcurrent protection that the embodiment of the invention provided comprises induction by current module 1 and the first input end IN1 that links to each other with described induction by current module 1, the second input IN2 and the first output OUT1, wherein:
When the electric current that flows through described first input end IN1 and the described second input IN2 surpassed first predetermined value, described induction by current module 1 was exported first drive signal by the described first output OUT1.
Because in the circuit overcurrent protection that the embodiment of the invention provided, when the electric current that flows through the first input end IN1 and the second input IN2 surpasses first predetermined value, induction by current module 1 can be exported first drive signal by the first output OUT1, this shows, if with first input end IN1 and the second input IN2 be connected in power consumption device 10 as shown in Figure 7 (for example: the LED lamp bar in the television set) link to each other and for the AOUT of electric energy output end as shown in Figure 3 of power consumption device 10 power supplies (for example: in the time of the electric energy output end AOUT of television set booster circuit), induction by current module 1 can be gathered by the first input end IN1 and the second input IN2, and then identification flows through power consumption device 10 and is the current value of the electric current of the electric energy output end AOUT of power consumption device 10 power supply, thereby judges the phenomenon that whether has overcurrent on the power consumption device 10;
Simultaneously; because induction by current module 1 also can be when the electric current that flows through the first input end IN1 and the second input IN2 surpasses first predetermined value; export first drive signal; promptly the state that whether has the overcurrent phenomenon on the power consumption device 10 as shown in Figure 7 form with drive signal can also be sent by the first output OUT1; so in actual production; operating personnel can be redefined for first predetermined value lowest high-current value that power consumption device 10 operate as normal can bear; like this; when overcurrent or short circuit take place over the ground and cause the phenomenon of overcurrent takes place in power consumption device 10; the overcurrent phenomenons can take place and before damaging at power consumption devices such as LED lamp bar 10 in induction by current module 1; the state that power consumption device 10 is taken place the overcurrent phenomenons sends by the first output OUT1 with the form of drive signal, so solved protective circuit in the existing television set can't be sent drive signal in LED lamp bar generation overcurrent phenomenon before damaging technical problem.
As shown in Figure 3, the first input end IN1 and the second input IN2 link to each other with the electric energy output end AOUT of output current successively along the direction of current delivery respectively in the present embodiment;
Induction by current module 1 comprises first resistance R 1, second resistance R 2 and a PNP triode V1 as shown in Figure 3 as shown in Figure 2, wherein:
The emitter of the one PNP triode V1 links to each other with first input end IN1, and the base stage of a PNP triode V1 links to each other with the second input IN2, and the collector electrode of a PNP triode V1 links to each other with second resistance R 2 of the first output OUT1 and ground connection respectively.
When big electric current flows through electric energy output end AOUT and flow into as shown in Figure 7 power consumption device 10, owing to flow through the electric current at the two ends of first resistance R 1 as shown in Figure 3, can produce pressure drop, so the current potential on the first input end IN1 is higher than the current potential on the second input IN2, the voltage of the one PNP triode V1 base stage is higher than the voltage of a PNP triode V1 emitter, the one PNP triode V1 conducting, at this moment, the first input end IN1 that links to each other with the collector electrode of a PNP triode V1 just can send out first drive signal.The size of the magnitude of voltage of first drive signal can be adjusted according to the resistance of first resistance R 1 and the tube voltage drop of PNP triode V1PN knot in the present embodiment.Second resistance R 2 of ground connection is used for a PNP triode V1 is carried out ground protection, and then guarantees the reliability and security of a PNP triode V1.
In the actual production in the present embodiment any resistance both can only be that a resistance also can and/or be formed in parallel for the series connection of a plurality of resistance.For example: first resistance R 1 is formed by connecting by resistance R 11, resistance R 12 and 13 3 resistance of resistance R in the present embodiment.
As a kind of improvement of present embodiment, induction by current module 1 also comprises first capacitor C 1, the first diode VD1 as shown in Figure 3 as shown in Figure 2, wherein:
The two poles of the earth of first capacitor C 1 link to each other with the first input end IN1 and the second input IN2 respectively;
The positive pole of the first diode VD1 links to each other with collector electrode, second resistance R 2 of a PNP triode V1 respectively, and the negative pole of the first diode VD1 links to each other with the first output OUT1.
The first diode VD1 has good unilateral conduction; can guarantee that the single input of direction of first drive signal of first output OUT1 output receives the chip (for example: chip for driving 3 as shown in Figure 7) of first drive signal; but also the electric current of the first diode VD1 that can avoid flowing through can not pour in down a chimney, and then can protect a PNP triode V1.
In the present embodiment as shown in Figure 2 induction by current module 1 comprise that also the 3rd resistance R 3, the three resistance R 3 are connected between the collector electrode and the first output OUT1 of a PNP triode V1 as shown in Figure 3.
The 3rd resistance R 3 and first resistance R 1 play the effect of dividing potential drop jointly, carry out to avoid the magnitude of voltage of first drive signal of first output OUT1 output too big, and the chip (for example: chip for driving 3 as shown in Figure 7) that causes a PNP triode V1 and receive first drive signal is damaged.
The 3rd resistance R 3 and first resistance R 1 can only be that a resistance also can and/or be formed in parallel for a plurality of resistance series connection in like manner, and the 3rd resistance R 3 is in series by resistance R 31 and 32 two resistance of resistance R in the present embodiment.
In the present embodiment as shown in Figure 2 induction by current module 1 also comprise the 4th resistance R 4 and the 5th resistance R 5 as shown in Figure 4, wherein:
The 4th resistance R 4 is connected between the negative pole of the electric energy output end AOUT and the first diode VD1;
The negative pole of the first diode VD1 links to each other with the 5th resistance R 5 and the first output OUT1 of the 4th resistance R 4, ground connection respectively.
With the 3rd resistance R 3 and first resistance R 1 as shown in Figure 3 in like manner; the 4th resistance R 4 and the 5th resistance R 5 play the effect of dividing potential drop jointly as shown in Figure 4; can be when the electric current that flows through electric energy output end AOUT surpass first predetermined value; avoid the voltage of electric energy output end AOUT output too big; and the chip (for example: chip for driving 3 as shown in Figure 7) that causes linking to each other with the first output OUT1 is damaged, and then can further strengthen the reliability and security of the electronic equipment that this circuit overcurrent protection is set.
As shown in Figure 5, as another improvement of present embodiment, circuit overcurrent protection also comprises isolation boosting module 2 and the second output OUT2 that links to each other with isolation boosting module 2 in the present embodiment, wherein:
Because at present; the voltage request of drive signal that part has the chip (for example: power management chip 6 as shown in figure 10) of circuit protection function is higher than by the chip of first drive (for example: chip for driving 3 as shown in figure 10), so need boost to importing the chip with circuit protection function higher to the drive signal voltage request after the second higher drive signal of voltage again to first drive signal.
This shows; magnitude of voltage can be more than the kind of the chip with circuit protection function that higher drive signal can drive; so isolation boosting module 2 has enlarged the scope of the chip with circuit protection function that circuit overcurrent protection of the present invention can drive, and then the application scenario of also having improved circuit overcurrent protection of the present invention.
In the present embodiment as shown in Figure 5 isolation boosting module 2 comprise as shown in Figure 6 drawing on NPN triode Q, the optical coupler N, first and draw power supply VCC2 and the 2nd PNP triode V2 on the power supply VCC1, second, wherein:
The base stage of NPN triode Q links to each other with the first output OUT1, the grounded emitter of NPN triode Q, and the collector electrode of NPN triode Q links to each other with the negative pole of photophore in the optical coupler N;
Draw power supply VCC1 to link to each other on the positive pole and first of photophore in the optical coupler N, in the optical coupler N positive pole of light-receiving device respectively with second on draw the base stage of power supply VCC2 and the 2nd PNP triode V2 to link to each other, the minus earth of the interior light-receiving device of optical coupler N;
Draw power supply VCC2 to link to each other on the emitter and second of the 2nd PNP triode V2, the collector electrode of the 2nd PNP triode V2 links to each other with the second output OUT2.
Because the base stage of NPN triode Q links to each other with the first output OUT1 as shown in Figure 6, when the base stage of NPN triode Q receives first drive signal of first output OUT1 output, the 2nd PNP triode V2 conducting, at this moment, the positive pole of photophore is luminous with its negative pole formation closed-loop path in the optical coupler N, drawing power supply VCC1 on first is photophore power supply in the optical coupler N, light-receiving device in the optical coupler N sense in the optical coupler N photophore luminous after, the positive pole and the negative pole conducting of the light-receiving device in the optical coupler N;
Simultaneously, because the negative pole of the light-receiving device in the optical coupler N is a ground connection, so, this moment, the base voltage of the 2nd PNP triode V2 reduced, the 2nd PNP triode V2 conducting, draw the electric energy of power supply VCC2 output to export on second through the 2nd PNP triode V2 and from the second output OUT2, at this moment, the second output OUT2 exports second drive signal, the magnitude of voltage of second drive signal depends on the tube voltage drop of the output voltage that draws power supply VCC2 on second and the 2nd PNP triode V2PN knot, because the tube voltage drop of the 2nd PNP triode V2PN knot is less usually, and the tube voltage drop difference of various the 2nd PNP triode V2PN knots and little, so, when needing higher second drive signal of magnitude of voltage, can change the magnitude of voltage of output voltage higher second on draw power supply VCC2; Otherwise, when needing lower second drive signal of magnitude of voltage, can change the magnitude of voltage of output voltage lower second on draw power supply VCC2.
Optical coupler N not only has the effect that photoelectricity is isolated, and has better anti-jamming capability, so can avoid the influence of first drive signal to second drive signal.
The employed above-mentioned components and parts of present embodiment are more common electronic devices and components, have advantage with low cost, that be convenient to connect, so help to reduce the cost of oversampling circuit protective circuit of the present invention.
In the present embodiment as shown in Figure 5 isolation boosting module 2 also comprise the 6th resistance R 6, voltage stabilizing didoe VZ and/or the second diode VD2 of ground connection as shown in Figure 6, wherein:
The collector electrode of the 2nd PNP triode V2 links to each other with the second output OUT2 and the 6th resistance R 6 respectively;
The positive pole of voltage stabilizing didoe VZ links to each other with the positive pole of light-receiving device in the optical coupler N, the negative pole of voltage stabilizing didoe VZ respectively with second on draw the base stage of power supply VCC2, the 2nd PNP triode V2 to link to each other;
The positive pole of the second diode VD2 links to each other with the collector electrode of the 2nd PNP triode V2, and the negative pole of the second diode VD2 links to each other with the second output OUT2, the 6th resistance R 6 respectively.
The 6th resistance R 6 of ground connection can play the effect of ground protection, can prevent that the magnitude of voltage of second drive signal from causing damage to the chip (for example: power management chip 6 as shown in figure 10) that links to each other with the second output OUT2 too greatly.
When the positive pole of voltage stabilizing didoe VZ light-receiving device in optical coupler N and negative pole conducting, can keep a lower stable voltage, keep the 2nd PNP triode V2 and be in conducting state, and then guarantee output second drive signal that the second output OUT2 is reliable, stable.
With the first diode VD1 in like manner; the second diode VD2 has good unilateral conduction; can guarantee that the single input of direction of second drive signal of second output OUT2 output receives the chip (for example: power management chip 6 as shown in figure 10) of second drive signal; simultaneously; the electric current of the second diode VD2 of can also avoiding flowing through pours in down a chimney, and then can protect the 2nd PNP triode V2.
In the present embodiment as shown in Figure 5 isolation boosting module 2 be preferably the 6th resistance R 6, voltage stabilizing didoe VZ and the second diode VD2 that comprises ground connection simultaneously, certainly, in the present embodiment isolation boosting module 2 also can only comprise the 6th resistance R 6, voltage stabilizing didoe VZ and the second diode VD2 one of them or wherein two.
In the present embodiment as shown in Figure 5 isolation boosting module 2 also comprise the 7th resistance R 7, the 8th resistance R 8 and the 9th resistance R 9 as shown in Figure 6, wherein:
The 7th resistance R 7 is connected between the emitter that draws power supply VCC2 and the 2nd PNP triode V2 on second;
The 8th resistance R 8 is connected between the base stage of the negative pole that draws power supply VCC2 and voltage stabilizing didoe VZ on second, the 2nd PNP triode V2;
The 9th resistance R 9 is connected between the base stage of the 2nd PNP triode V2 and the negative pole of voltage stabilizing didoe VZ, described the 8th resistance R 8;
The resistance of the 9th resistance R 9 greater than the resistance of the 7th resistance R 7, the seven resistance R 7 greater than the 8th resistance R 8.
The 7th resistance R 7, the 8th resistance R 8 and the 9th resistance R 9 can be shared the output voltage that draws power supply VCC2 on second jointly, the resistance of the 9th resistance R 9 is greater than the 7th resistance R 7, the resistance of the 7th resistance R 7 is during greater than the 8th resistance R 8, can guarantee that optical coupler N is not during conducting, the voltage of the 2nd PNP triode V2 emitter is less than the voltage of the 2nd PNP triode V2 base stage, thereby be in cut-off state, and then can avoid the 2nd PNP triode V2 at coupler not during conducting, the 2nd PNP triode V2 conducting, when causing that the overcurrent phenomenon does not take place power consumption device 10 as shown in figure 10, output second drive signal of the second output OUT2 mistake.
As shown in Figure 7, the television set that the embodiment of the invention provided comprises the circuit overcurrent protection that chip for driving 3, booster circuit 5, power consumption device 10 and the invention described above embodiment are provided, wherein:
The first input end IN1 of circuit overcurrent protection and the second input IN2 are connected between the electric energy output end AOUT and power consumption device 10 of booster circuit 5;
Chip for driving 3 links to each other with the first output OUT1 and booster circuit 5 respectively;
When the first output OUT1 imported first drive signal to chip for driving 3, chip for driving 3 entered lock-out state.
Because the television set that the embodiment of the invention provided comprises the circuit overcurrent protection that the invention described above embodiment is provided, so the television set that the embodiment of the invention provided has identical technical characterictic with the circuit overcurrent protection that the invention described above embodiment is provided, so not only can obtain identical technique effect, and can solve identical technical problem;
When the circuit overcurrent protection that the invention described above embodiment is provided is applied to protect on the television set as shown in Figure 7 power consumption device (for example: LED lamp bar) 10 the time, if operating personnel are redefined for the lowest high-current value that the booster circuit 5 LED lamp bar operate as normal that electric energy output end AOUT connected as shown in Figure 3 can bear (certainly with first predetermined value, first predetermined value also can be worth less than this), then between the electric energy output end AOUT and power consumption device 10 that the first input end IN1 and the second input IN2 of circuit overcurrent protection is connected to booster circuit 5, when simultaneously the first output OUT1 of chip for driving 3 and circuit overcurrent protection and booster circuit 5 being linked to each other; When the electric current that flows through booster circuit 5 electric energy output end AOUT and power consumption device 10 surpasses the lowest high-current value that LED lamp bar operate as normal can bear; the first output OUT1 can be to chip for driving 3 inputs first drive signal; at this moment; chip for driving 3 can enter lock-out state; and when chip for driving 3 enters lock-out state; be subjected to the electric energy output end AOUT of the booster circuit 5 of chip for driving 3 controls can stop to export electric energy; and then the electric current that can prevent to surpass the lowest high-current value that LED lamp bar operate as normal can bear causes damage to LED lamp bar; so the protective circuit that has solved in the existing television set can't be sent drive signal in LED lamp bar generation overcurrent phenomenon before damaging, and then the technical problem that causes LED lamp bar easily to damage because of the overcurrent phenomenon.
In the present embodiment as shown in Figure 7 chip for driving 3 be preferably as shown in Figure 8 AP3039 chip.When chip for driving 3 is the AP3039 chip, the first output OUT1 of the circuit overcurrent protection that the embodiment of the invention provided links to each other with the OV pin on the AP3039 chip, the OUT pin of AP3039 chip links to each other with booster circuit 5, the AP3039 chip just can receive first drive signal by the OV pin, by the OUT pin booster circuit 5 is transmitted control signal, and then whether control booster circuit 5 boost the electric energy of power supply 4 outputs, and the input of the electric energy after will boosting power consumption device (for example: LED lamp bar) 10;
As shown in Figure 9; when using the AP3039 chip as chip for driving 3 as shown in Figure 7; when being subjected to the power consumption device operate as normal of the circuit overcurrent protection protection that the embodiment of the invention provides and during power consumption device generation overcurrent; voltage waveform on the AP3039 chip on the OV pin is the voltage waveform of first drive signal that the first output OUT1 exported, and the voltage waveform on the OUT pin is the voltage waveform of the control signal that booster circuit 5 is sent by the OUT pin.
As shown in figure 10, the present embodiment television set also comprises isolation boosting module 2 that power management chip 6, power supply 4, the invention described above embodiment circuit overcurrent protection are provided and the second output OUT2 that links to each other with isolation boosting module 2, wherein:
When the second output OUT2 imported second drive signal to power management chip 6, power management chip 6 entered the frequency hopping state, and when not having second drive signal input power management chip 6, power management chip 6 withdraws from the frequency hopping state.
When the electric current that flows through booster circuit 5 electric energy output end AOUT surpasses the lowest high-current value that LED lamp bar operate as normal can bear; the second output OUT2 can be to power management chip 6 inputs second drive signal; at this moment; power management chip 6 can enter the frequency hopping state; when power management chip 6 enters the frequency hopping state; be subjected to the power supply 4 of power management chip 6 controls can stop to export electric energy; and then the electric current that also can prevent to surpass the lowest high-current value that LED lamp bar operate as normal can bear causes damage to LED lamp bar; so the protective circuit that also can solve in the existing television set can't be sent drive signal in LED lamp bar generation overcurrent phenomenon before damaging, the technical problem that causes LED lamp bar easily to damage because of the overcurrent phenomenon.
The television set that present embodiment provided is preferably and only comprises chip for driving 3 as shown in Figure 7 or only comprise power management chip 6 as shown in figure 13.At this moment, only need chip for driving 3 or power management chip 6 both one of them (for example: the purpose of overcurrent protection LED lamp bar) just can realize to power consumption device 10 in the television set.
Certainly; the present embodiment television set also can comprise chip for driving 3 and power management chip 6 as shown in figure 10 simultaneously; during concrete the use, can only use chip for driving 3 and power management chip 6 both one of them that power consumption device in the television set 10 is carried out overcurrent protection as required.At this moment; can be when chip for driving 3 and power management chip 6 both one of them break down; wherein another proceeds overcurrent protection to power consumption device 10 in the television set in use, thereby can further improve the reliability and security of circuit overcurrent protection of the present invention.
In the present embodiment as shown in figure 10 power management chip 6 be preferably NCP1396 chip as shown in figure 11; when power management chip 6 is the NCP1396 chip; the second output OUT2 of the circuit overcurrent protection that the embodiment of the invention provided links to each other with the FB pin on the NCP1396 chip; MUPPER_6 pin on the NCP1396 chip links to each other with power supply 4; the NCP1396 chip receives second drive signal that the second output OUT2 exports by the FB pin, by the MUPPER_6 pin power supply 4 is transmitted control signal.
As shown in figure 12; when using the conduct of NCP1396 chip as Figure 10 or power management chip 6 shown in Figure 13; when being subjected to the power consumption device operate as normal of the circuit overcurrent protection protection that the embodiment of the invention provides and during power consumption device generation overcurrent; voltage waveform on the NCP1396 chip on the FB pin is the voltage waveform of second drive signal that the second output OUT2 exported, and the voltage waveform on the MUPPER_6 pin is the voltage waveform of the control signal that power supply 4 is sent by the MUPPER_6 pin.
When chip for driving 3 used as shown in Figure 8 AP3039 chip, power management chip 6 to use as shown in figure 11 the NCP1396 chip, the voltage of first drive signal was to be preferably 1.25V more than the 1.0V, and the voltage of second drive signal is more than the 6.0V, to be preferably 6.5V.
Certainly, chip for driving 3 and power management chip 6 also can use outside disclosed AP3039 chip of the invention described above embodiment and the NCP1396 chip other to have the circuit protection chip of lock function or frequency hopping function in the present embodiment.Simultaneously, the voltage of the voltage of first drive signal and second drive signal can be adjusted by the mode of components and parts model or parameter value in the change circuit overcurrent protection according to the type of employed circuit protection chip.
Drawing the output voltage of power supply VCC1 on first in the present embodiment is 3～7V, is preferably 5V, and drawing the output voltage of power supply VCC2 on second is 8～20V, is preferably 12V.
Facts have proved; when drawing on first the output voltage that draws power supply VCC2 on power supply VCC1 and second to select above-mentioned magnitude of voltage for use in the present embodiment; the present embodiment circuit overcurrent protection is when power consumption device overcurrent, and first drive signal of output and second drive signal all can effectively drive AP3039 chip or NCP1396 chip.
The above; only be the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.
Claims (8)
1. a circuit overcurrent protection is characterized in that, comprises induction by current module and the first input end that links to each other with described induction by current module, second input and first output, wherein:
When the electric current that flows through described first input end and described second input surpassed first predetermined value, described induction by current module was exported first drive signal by described first output;
Described first input end and described second input link to each other with the electric energy output end of the described electric current of output successively along the direction of described current delivery respectively;
Described induction by current module comprises first resistance, second resistance and a PNP triode, wherein:
Described first resistance is connected between described first input end and described second input;
The emitter of a described PNP triode links to each other with described first input end, the base stage of a described PNP triode links to each other with described second input, and the collector electrode of a described PNP triode links to each other with described second resistance of described first output and ground connection respectively;
Described induction by current module also comprises first electric capacity and first diode, wherein:
The two poles of the earth of described first electric capacity link to each other with described first input end and described second input respectively;
The positive pole of described first diode links to each other with the collector electrode of a described PNP triode, described second resistance respectively, and the negative pole of described first diode links to each other with described first output.
2. circuit overcurrent protection according to claim 1 is characterized in that, described induction by current module also comprises the 4th resistance and the 5th resistance, wherein:
Described the 4th resistance is connected between the negative pole of described electric energy output end and described first diode;
The negative pole of described first diode links to each other with described the 5th resistance and described first output of described the 4th resistance, ground connection respectively.
3. circuit overcurrent protection according to claim 1 is characterized in that, this circuit overcurrent protection also comprises isolation boosting module and second output that links to each other with described isolation boosting module, wherein:
Described isolation boosting module links to each other with described first output, described isolation boosting module is used for being higher than second drive signal of described first drive signal by the described second output output voltage values when receiving described first drive signal of described first output output.
4. circuit overcurrent protection according to claim 3 is characterized in that, described isolation boosting module comprises drawing on NPN triode, the optical coupler, first draws power supply and the 2nd PNP triode on the power supply, second, wherein:
The base stage of described NPN triode links to each other with described first output, the grounded emitter of described NPN triode, and the collector electrode of described NPN triode links to each other with the negative pole of photophore in the described optical coupler;
Draw power supply to link to each other on the positive pole and described first of photophore in the described optical coupler, in the described optical coupler positive pole of light-receiving device respectively with described second on draw the base stage of power supply and described the 2nd PNP triode to link to each other, the minus earth of the interior light-receiving device of described optical coupler;
Draw power supply to link to each other on the emitter of described the 2nd PNP triode and described second, the collector electrode of described the 2nd PNP triode links to each other with described second output.
5. circuit overcurrent protection according to claim 4 is characterized in that, described isolation boosting module also comprises the 6th resistance, voltage stabilizing didoe and second diode of ground connection, wherein:
The collector electrode of described the 2nd PNP triode links to each other with described second output and described the 6th resistance respectively;
The positive pole of described voltage stabilizing didoe links to each other with the positive pole of light-receiving device in the described optical coupler, the negative pole of described voltage stabilizing didoe respectively with described second on draw the base stage of power supply, described the 2nd PNP triode to link to each other;
The positive pole of described second diode links to each other with the collector electrode of described the 2nd PNP triode, and the negative pole of described second diode links to each other with described second output, described the 6th resistance respectively.
6. circuit overcurrent protection according to claim 5 is characterized in that, described isolation boosting module also comprises the 7th resistance, the 8th resistance and the 9th resistance, wherein:
Described the 7th resistance is connected between the emitter that draws power supply and described the 2nd PNP triode on described second;
Described the 8th resistance is connected between the base stage of the negative pole that draws power supply and described voltage stabilizing didoe on described second, described the 2nd PNP triode;
Described the 9th resistance is connected between the base stage of described the 2nd PNP triode and the negative pole of described voltage stabilizing didoe, described the 8th resistance;
The resistance of described the 9th resistance is greater than described the 7th resistance, and the resistance of described the 7th resistance is greater than described the 8th resistance.
7. a television set is characterized in that, comprises the arbitrary described circuit overcurrent protection of chip for driving, booster circuit, power consumption device and claim 3 to 6, wherein:
The described first input end of described circuit overcurrent protection and described second input are connected between the electric energy output end and described power consumption device of described booster circuit;
Described chip for driving links to each other with described first output and described booster circuit respectively;
When described first output was imported described first drive signal to described chip for driving, described chip for driving entered lock-out state.
8. television set according to claim 7 is characterized in that, this television set also comprises power supply, power management chip, described isolation boosting module and second output that links to each other with described isolation boosting module, wherein:
Described isolation boosting module links to each other with described first output, described isolation boosting module is used for being higher than second drive signal of described first drive signal by the described second output output voltage values when receiving described first drive signal of described first output output;
Described power management chip links to each other with described second output and described power supply respectively;
When described second output is imported described second drive signal to described power management chip, described power management chip enters the frequency hopping state, when no described second drive signal was imported described power management chip, described power management chip withdrawed from the frequency hopping state.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010270418 CN101964511B (en) | 2010-09-02 | 2010-09-02 | Overcurrent protection circuit and television |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010270418 CN101964511B (en) | 2010-09-02 | 2010-09-02 | Overcurrent protection circuit and television |
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| Publication Number | Publication Date |
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| CN101964511A CN101964511A (en) | 2011-02-02 |
| CN101964511B true CN101964511B (en) | 2013-07-24 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201010270418 Expired - Fee Related CN101964511B (en) | 2010-09-02 | 2010-09-02 | Overcurrent protection circuit and television |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103390877B (en) * | 2013-08-07 | 2016-12-28 | 北京经纬恒润科技有限公司 | A kind of over-current detection and protection circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101232171A (en) * | 2007-01-24 | 2008-07-30 | 青岛海信电器股份有限公司 | Television power supply protective circuit |
| CN201332257Y (en) * | 2009-01-13 | 2009-10-21 | 青岛海信电器股份有限公司 | Power protecting circuit and TV set with the circuit |
| CN201383848Y (en) * | 2009-04-29 | 2010-01-13 | 青岛海信电器股份有限公司 | Booster circuit and television with booster circuit |
| CN202111450U (en) * | 2010-09-02 | 2012-01-11 | 青岛海信电器股份有限公司 | Overcurrent protection circuit and television |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1811639A1 (en) * | 2006-01-23 | 2007-07-25 | Thomson Licensing S.A. | Overpower-protection circuit and power supply apparatus having the same |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101232171A (en) * | 2007-01-24 | 2008-07-30 | 青岛海信电器股份有限公司 | Television power supply protective circuit |
| CN201332257Y (en) * | 2009-01-13 | 2009-10-21 | 青岛海信电器股份有限公司 | Power protecting circuit and TV set with the circuit |
| CN201383848Y (en) * | 2009-04-29 | 2010-01-13 | 青岛海信电器股份有限公司 | Booster circuit and television with booster circuit |
| CN202111450U (en) * | 2010-09-02 | 2012-01-11 | 青岛海信电器股份有限公司 | Overcurrent protection circuit and television |
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| CN101964511A (en) | 2011-02-02 |
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