CN201946974U - Overvoltage buffer circuit, overvoltage protection circuit and television - Google Patents
Overvoltage buffer circuit, overvoltage protection circuit and television Download PDFInfo
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- CN201946974U CN201946974U CN2011200198300U CN201120019830U CN201946974U CN 201946974 U CN201946974 U CN 201946974U CN 2011200198300 U CN2011200198300 U CN 2011200198300U CN 201120019830 U CN201120019830 U CN 201120019830U CN 201946974 U CN201946974 U CN 201946974U
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Abstract
The utility model provides an overvoltage buffer circuit, an overvoltage protection circuit and a television, relates to the electronic technology field and solves the technical problem in the prior art that the television is often difficult to start up. The overvoltage buffer circuit comprises a first resistor module and an instant partial pressure module, and the voltage output end is grounded through the first resistor module; and the instant partial pressure module is used for reducing the voltage of the first resistor module when the original output voltage of the voltage output end is higher than the predetermined protection voltage. The overvoltage protection circuit comprises a protection module, a test end, a control terminal and the overvoltage buffer circuit disclosed by the utility model, wherein the protection module is used for sending a control command to a boost circuit through the control terminal and controlling the boost circuit to stop working when the voltage on the first resistor module is higher than the predetermined safety voltage. The television comprises the overvoltage protection circuit disclosed by the utility mode. The utility model is used for improving the success rate of the starting up of the television.
Description
Technical field
The utility model relates to electronic technology field, the television set that be specifically related to a kind of overvoltage buffer circuit, is provided with the overvoltage crowbar of this overvoltage buffer circuit and is provided with this overvoltage crowbar.
Background technology
Along with the develop rapidly of electronic technology, television set has become one of household electrical appliance the most commonly used in people's daily life.At present, little, the lightweight liquid crystal TV set of volume more and more is subjected to client's favor.
Backlight is the important power consumption components in the liquid crystal TV set, and it is used for when liquid crystal TV set is started shooting, and for liquid crystal TV set provides backlight, thereby makes that liquid crystal TV set can display image.In the prior art, the important power consumption components in the television set is provided with overvoltage crowbar usually.Backlight with liquid crystal TV set is an example; the booster circuit of backlight just is connected with overvoltage crowbar, with the voltage that prevents to be higher than the backlight safe voltage from being that the voltage output end of the booster circuit of backlight power supply inputs to backlight and backlight is caused damage.
As shown in Figure 1, existing overvoltage crowbar generally includes backlight overvoltage protection chip CP, control end 6, the first resistance r1, the second resistance r2 and test lead 3, wherein:
The voltage output end Vout of booster circuit is the first resistance r1 and the second resistance r2 ground connection by connecting successively;
Backlight overvoltage protection chip CP links to each other with test lead 3 and control end 6 respectively;
Backlight overvoltage protection chip CP is used for surveying voltage on the second resistance r2 by test lead 3, and the voltage on the second resistance r2 is when exceeding predetermined safe voltage, and by 6 pairs of booster circuit sending controling instructions of control end, the control booster circuit quits work;
Booster circuit inputs to backlight by voltage output end Vout after being used for receiving voltage and the voltage that voltage input end Vin is received being increased to the operating voltage of backlight by voltage input end Vin, thereby powers for backlight.
Because the first resistance r1 and the second resistance r2 have constituted bleeder circuit in the foregoing circuit, there are specific proportional relation in voltage on the second resistance r2 and the output voltage of voltage output end Vout, test lead 3 can calculate the output voltage of voltage output end Vout according to this proportional relation, so just can be realized indirectly testing to the output voltage of voltage output end Vout by surveying voltage on the second resistance r2.
In realizing process of the present utility model, the inventor finds that there are the following problems at least in the prior art:
In the prior art; during television boot-strap; backlight will provide backlight for television set as shown in Figure 1; then at first start booster circuit for the backlight power supply; but the too high phenomenon of instantaneous voltage takes place in the process that booster circuit has just started easily; it is the instantaneous backlight safe voltage that is higher than of voltage meeting of the voltage output end Vout output of booster circuit; at this moment; because backlight overvoltage protection chip CP can play the effect of overvoltage protection; when the voltage of voltage output end Vout output is higher than the backlight safe voltage; can be by 6 pairs of booster circuit sending controling instructions of control end; the control booster circuit quits work, and booster circuit is when quitting work, and it is normally luminous that the voltage of voltage output end Vout output can't drive backlight; make normally display image of liquid crystal TV set, finally cause the liquid crystal TV set boot failure.
The utility model content
The utility model embodiment provides a kind of overvoltage buffer circuit on the one hand, provides a kind of overvoltage crowbar that is provided with this overvoltage buffer circuit on the other hand; also provide a kind of television set that is provided with this overvoltage crowbar on the one hand again, solved prior art and existed television set that the technical problem of boot failure easily takes place.
For achieving the above object, embodiment of the present utility model adopts following technical scheme:
The overvoltage buffer circuit that the utility model embodiment provides comprises first resistive module and the instantaneous division module that link to each other with voltage output end, wherein:
Described voltage output end is by the described first resistive module ground connection;
Described instantaneous division module is in parallel with described first resistive module;
Described instantaneous division module when being used for initial output voltage at described voltage output end and exceeding predetermined protection voltage, reduces the voltage on described first resistive module.
Further, this overvoltage buffer circuit also comprises second resistive module, and described second resistive module is electrically connected between described first resistive module and the described voltage output end.
Further, described instantaneous division module at least one electric capacity or described instantaneous division module be two with last capacitances in series and/or be formed in parallel;
And/or, described first resistive module at least one resistance or be two with last resistance string connection and/or be formed in parallel;
And/or, described second resistive module at least one resistance or be two with last resistance string connection and/or be formed in parallel.
Further, the appearance value of described instantaneous division module is not less than 50nF.
Further, the appearance value of described instantaneous division module is between 100nF～1000nF.
This overvoltage crowbar comprises the overvoltage buffer circuit that protection module, test lead, control end and above-mentioned the utility model embodiment are provided, wherein:
Described test lead is electrically connected between described first resistive module and the described voltage output end;
Described protection module links to each other with described test lead and described control end respectively;
Described protection module; be used for surveying voltage on described first resistive module by described test lead; and the voltage on described first resistive module, is controlled described booster circuit and is quit work the booster circuit sending controling instruction by described control end when exceeding predetermined safe voltage.
Further, described protection module is the overvoltage protection chip, and described overvoltage protection chip comprises comparator and controller, wherein:
Described comparator is used for the voltage on the more described test lead and the size of predetermined safe voltage, and comparative result is imported described controller;
Described controller when being used for voltage on described test lead greater than predetermined safe voltage,, being controlled described booster circuit and is quit work described booster circuit sending controling instruction by described control end.
Further, described booster circuit is the BOOST booster circuit.
Further, this overvoltage buffer circuit, also comprise described second resistive module, described test lead is electrically connected between described first resistive module and described second resistive module, and/or, described booster circuit comprises the electrochemical capacitor of inductance, first diode, metal-oxide-semiconductor, voltage input end, described voltage output end and ground connection, wherein:
A wherein end of described inductance links to each other with described voltage input end, and the wherein other end of described inductance links to each other with the drain electrode anodal and described metal-oxide-semiconductor of described first diode respectively;
The negative pole of described first diode links to each other with the anodal and described voltage output end of electrochemical capacitor respectively;
The source electrode of described metal-oxide-semiconductor is electrically connected between described electrochemical capacitor negative pole and the ground;
The grid of described metal-oxide-semiconductor links to each other with described control end.
Further, described booster circuit also comprises the 3rd resistance, the 4th resistance, the 5th resistance and second diode, wherein:
Described the 3rd resistance links to each other with the grid of described metal-oxide-semiconductor and the source electrode of described metal-oxide-semiconductor respectively;
Described the 4th resistance links to each other with the grid and the described control end of described metal-oxide-semiconductor respectively;
The positive pole of described second diode links to each other with the grid of described metal-oxide-semiconductor, and the negative pole of described second diode links to each other with described control end;
A wherein end of described the 5th resistance links to each other with the source electrode of described metal-oxide-semiconductor and described the 3rd resistance, and the wherein other end of described the 5th resistance is electrically connected between described electrochemical capacitor and the described ground;
And/or described booster circuit also comprises filter capacitor, and described filter capacitor is in parallel with described electrochemical capacitor.
This television set comprises the overvoltage crowbar that backlight, booster circuit and above-mentioned the utility model embodiment are provided, and the described voltage output end of described booster circuit is described backlight power supply.
Compared with prior art, the utility model embodiment provides and can produce following at least technique effect in above-mentioned arbitrary technical scheme:
Because the instantaneous division module in the overvoltage buffer circuit that the utility model embodiment is provided, can exceed at the initial output voltage of voltage output end when being scheduled to protection voltage, reduce the voltage on first resistive module, and the voltage on first resistive module is when low, the probability that voltage on first resistive module exceeds predetermined safe voltage is lower, and then the voltage of protection module on first resistive module is when exceeding predetermined safe voltage, the out-of-work probability of control booster circuit is also lower, the out-of-work probability of booster circuit is low more, the reliability that the power consumption device (for example backlight) that then relies on voltage output end to power is powered is good more, and then the television boot-strap failed probability also can greatly reduce, and exists television set that the technical problem of boot failure easily takes place so solved prior art;
Simultaneously; because instantaneous division module; only can exceed when being scheduled to protection voltage at the initial output voltage of voltage output end; reduce the voltage on first resistive module; in the process of television set and booster circuit operate as normal; even the output voltage of voltage output end exceeds predetermined protection voltage; instantaneous division module can not have influence on the voltage on first resistive module yet; still play the effect of overvoltage protection so can guarantee overvoltage crowbar, thereby the electronic equipment that can guarantee to rely on the power consumption device (for example backlight) of voltage output end power supply and this power consumption device is set (for example: fail safe television set).
Description of drawings
In order to be illustrated more clearly in the utility model embodiment 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 embodiment more of the present utility model, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.
The schematic diagram of annexation between each device of inside of the backlight overvoltage crowbar that provided in the prior art and the booster circuit is provided Fig. 1;
The schematic diagram of annexation between overvoltage buffer circuit that Fig. 2 provides for the utility model embodiment and the power consumption device;
The schematic diagram of annexation between overvoltage crowbar that Fig. 3 provides for the utility model embodiment and the power consumption device;
The schematic diagram of annexation between a kind of concrete enforcement circuit of the overvoltage crowbar that Fig. 4 provides for the utility model embodiment and the power consumption device.
Embodiment
Below in conjunction with the accompanying drawing among the utility model embodiment, the technical scheme among the utility model embodiment is clearly and completely described, obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment.Based on the embodiment in the utility model, the every other embodiment that those of ordinary skills are obtained under the prerequisite of not paying creative work belongs to the scope that the utility model is protected.
The utility model embodiment provides a kind of television set that makes that good, the with low cost overvoltage buffer circuit of boot failure and fail safe, the television set that the overvoltage crowbar of this overvoltage buffer circuit is set and is provided with this overvoltage crowbar be difficult for to take place.
As Fig. 2, Fig. 3 and shown in Figure 4, the overvoltage buffer circuit that the utility model embodiment is provided comprises the first resistive module R1 and the instantaneous division module 4 that link to each other with voltage output end Vout, wherein:
Voltage output end Vout is by the first resistive module R1 ground connection;
Because the instantaneous division module 4 in the overvoltage buffer circuit that the utility model embodiment is provided, can exceed at the initial output voltage of voltage output end Vout when being scheduled to protection voltage, reduce the voltage on the first resistive module R1, and the voltage on the first resistive module R1 is when low, the probability that voltage on the first resistive module R1 exceeds predetermined safe voltage is lower, and then when the voltage of protection module 5 on the first resistive module R1 exceeds predetermined safe voltage as shown in Figure 3, control booster circuit 2 out-of-work probability are also lower, booster circuit 2 out-of-work probability are low more, the reliability that the power consumption device (for example backlight 1) that then relies on voltage output end Vout to power is powered is good more, and then the television boot-strap failed probability also can greatly reduce, and exists television set that the technical problem of boot failure easily takes place so solved prior art;
Simultaneously; because instantaneous division module 4; only can exceed when being scheduled to protection voltage at the initial output voltage of voltage output end Vout; reduce the voltage on the first resistive module R1; in the process of television set and booster circuit 2 operate as normal; even the output voltage of voltage output end Vout exceeds predetermined protection voltage; instantaneous division module 4 can not have influence on the voltage on the first resistive module R1 yet; still play the effect of overvoltage protection so can guarantee overvoltage crowbar, thereby the electronic equipment that can guarantee to rely on the power consumption device (for example backlight 1) of voltage output end Vout power supply and this power consumption device is set (for example: fail safe television set).
The overvoltage buffer circuit that present embodiment provided also comprises the second resistive module R2 as shown in Figure 3, and the second resistive module R2 is electrically connected between the first resistive module R1 and the voltage output end Vout.
The second resistive module R2 and the first resistive module R1 constitute bleeder circuit jointly; the proportionate relationship of resistance value that can be by adjusting the second resistive module R2 and the resistance value of the first resistive module R1; adjust the size of the voltage on the second resistive module R2 and the first resistive module R1; obtaining the voltage of different magnitudes of voltage, and then enlarged the range of choice of protection module 5.
As shown in Figure 4, in the present embodiment instantaneous division module 4 at least one electric capacity or instantaneous division module 4 be two with last capacitances in series and/or be formed in parallel;
And/or, the first resistive module R1 at least one resistance or be two with last resistance string connection and/or be formed in parallel;
And/or, the second resistive module R2 at least one resistance or be two with last resistance string connection and/or be formed in parallel.
The first resistive module R1 and the second resistive module R2 have constituted bleeder circuit, so can share the output voltage on the voltage output end Vout jointly, voltage on the first resistive module R1 and the second resistive module R2 is directly proportional with the resistance value of himself, so when the output voltage on the voltage output end Vout was big, the voltage of being assigned on the first resistive module R1 and the second resistive module R2 also can be bigger.
Electric capacity is not only with low cost; and because electric capacity has the function of discharging and recharging; when the initial output voltage of voltage output end Vout is loaded on the electric capacity; electric capacity is in charged state; give voltage on the first resistive module R1 so can reduce the initial output voltage of voltage output end Vout; after charging is finished; the electric energy that electric capacity discharged is very limited to the influence of circuit; so can not have influence on the voltage on the first resistive module R1; thereby in the time of can guaranteeing that booster circuit 2 and television set normally move; overvoltage crowbar still can have the function of overvoltage protection, and then has guaranteed the fail safe and the reliability of television set.Certainly, instantaneous division module 4 also can be other electronic devices outside the electric capacity in the present embodiment.
Resistance has with low cost, and the advantage of being convenient to be electrically connected helps to reduce the cost of the utility model overvoltage buffer circuit.Certainly, resistive module also can have other electronic devices of steady resistance for outside the resistance other in the present embodiment.
The appearance value of instantaneous division module 4 is not less than 50nF in the present embodiment, is preferably between 100nF～1000nF.Facts have proved: when the appearance value of instantaneous division module 4 is not less than 50nF, can significantly reduce the voltage on the second resistive module R2, the appearance value of especially instantaneous division module 4 is between 100nF～1000nF the time, and effect can be more obvious.
As shown in Figure 3 and Figure 4, overvoltage crowbar in the present embodiment comprises the overvoltage buffer circuit that protection module 5, test lead 3, control end 6 and above-mentioned the utility model embodiment are provided, wherein:
Because the identical technical characterictic of overvoltage buffer circuit that is provided with above-mentioned the utility model embodiment is provided the overvoltage crowbar that the utility model embodiment is provided, so also can produce identical technique effect, the identical technical problem of solution.
When protection module 5 can exceed the operating voltage of the power consumption device (for example backlight 1) that relies on voltage output end Vout power supply at the output voltage of voltage output end Vout; close the booster circuit 2 that links to each other with voltage output end Vout, thereby avoid booster circuit 2 to compare higher voltage by voltage output end Vout output voltage values.
As shown in Figure 3, protection module 5 is overvoltage protection chip (or claiming chip for driving, flip chip) in the present embodiment, and the overvoltage protection chip comprises comparator 51 and controller 52, wherein:
Predetermined safe voltage is meant the voltage that the resistance according to the operating voltage of the power consumption device (for example backlight 1) that relies on voltage output end Vout power supply and the first resistive module R1, the first resistive module R1 converts and obtains, when the voltage on the first resistive module R1 was higher than predetermined safe voltage, the output voltage of voltage output end Vout was higher than the operating voltage of the power consumption device (for example backlight 1) that relies on voltage output end Vout power supply.Comparator 51 and controller 52 both can be that the circuit in the overvoltage protection chip also can be independent chip.
It is high level or low level that the control command that controller 52 is sent is preferably digital signals format, when the control command of 52 pairs of control ends of controller, 6 transmissions is high level, booster circuit 2 work, otherwise, when the control command of 52 pairs of control ends of controller, 6 transmissions was low level, booster circuit 2 quit work.
Present embodiment overvoltage buffer circuit is preferably and comprises that the second resistive module R2, test lead 3 are electrically connected between the first resistive module R1 and the second resistive module R2, and instantaneous division module 4 is in parallel with the first resistive module R1.
The second resistive module R2 and the first resistive module R1 constitute bleeder circuit jointly; the proportionate relationship of resistance value that can be by adjusting the second resistive module R2 and the resistance value of the first resistive module R1; adjust the size of the voltage on the second resistive module R2 and the first resistive module R1; to obtain the voltage of different magnitudes of voltage; when test lead 3 is electrically connected between the first resistive module R1 and the second resistive module R2; test lead 3 measured magnitudes of voltage are the voltage on the first resistive module R1; so can be by adjusting the method for the first resistive module R1 and the second resistive module R2 resistance; adjust the size of the measured magnitude of voltage of test lead 3; and then select the protection module 5 of different rules and model; owing to can select the protection module 5 of multiple different rules and model, so enlarged the range of choice of protection module 5.
As shown in Figure 4, booster circuit 2 comprises the electrochemical capacitor C1 of inductance L, the first diode VD1, metal-oxide-semiconductor M, voltage input end Vin, voltage output end Vout and ground connection in the present embodiment, wherein:
A wherein end of inductance L links to each other with voltage input end Vin, and the wherein other end of inductance L links to each other with the positive pole of the first diode VD1 and the drain electrode of metal-oxide-semiconductor M respectively;
The negative pole of the first diode VD1 links to each other with positive pole and the voltage output end Vout of electrochemical capacitor C1 respectively;
The source electrode of metal-oxide-semiconductor M is electrically connected between electrochemical capacitor C1 negative pole and the ground;
The grid of metal-oxide-semiconductor M links to each other with control end 6.
Electrochemical capacitor C1 is in charging and discharging process, can raise by the magnitude of voltage of the voltage of voltage input end Vin input, in charging process, make metal-oxide-semiconductor M conducting, the first diode VD1 can prevent that electrochemical capacitor C1 from discharging over the ground, at first the electric current on the inductance L increases so that certain ratio is linear, this ratio is relevant with the inductance L size, when energy stored acquires a certain degree in the inductance L, make metal-oxide-semiconductor M end, at this moment, inductance L is electrochemical capacitor C1 charging, the voltage at electrochemical capacitor C1 two ends just can raise, thereby just can raise by the magnitude of voltage of the voltage of voltage input end Vin input.
It is simple that metal-oxide-semiconductor M has a manufacturing structure, and it is convenient to isolate, and simultaneously, so the advantage that volume is little, low in energy consumption is suitable being applied in the utility model.Certainly, metal-oxide-semiconductor M also can use other field effect transistor and even other triodes to substitute in the present embodiment, and electrochemical capacitor C1 also can use other electric capacity to substitute.
The 3rd resistance R 3 links to each other with the grid of metal-oxide-semiconductor M and the source electrode of metal-oxide-semiconductor M respectively;
The 4th resistance R 4 links to each other with grid and the control end 6 of metal-oxide-semiconductor M respectively;
The positive pole of the second diode VD2 links to each other with the grid of metal-oxide-semiconductor M, and the negative pole of the second diode VD2 links to each other with control end 6;
A wherein end of the 5th resistance R 5 links to each other with the source electrode of metal-oxide-semiconductor M and the 3rd resistance R 3, and the wherein other end of the 5th resistance R 5 is electrically connected between electrochemical capacitor C1 and the ground;
And/or booster circuit 2 also comprises filter capacitor C2, and filter capacitor C2 is in parallel with electrochemical capacitor C1.
Being provided with of the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5 and the second diode VD2 can increase the fail safe and the reliability of the booster circuit 2 that the utility model embodiment provided.
The high-frequency current of filter capacitor C2 in can filtering circuit, the electrochemical capacitor C1 low-frequency current in can filtering circuit, thus stable, the reliable transmission of electric current in the circuit guaranteed.
The overvoltage crowbar that is provided as Fig. 3 or backlight shown in Figure 41, booster circuit 2 and above-mentioned the utility model embodiment is provided the television set that the utility model embodiment is provided, and the voltage output end Vout of described booster circuit 2 is backlight 1 power supply.
Because overvoltage buffer circuit and the identical technical characterictic of overvoltage crowbar that is provided with above-mentioned the utility model embodiment is provided the television set that the utility model embodiment is provided, so also can produce identical technique effect, the identical technical problem of solution.
In the present embodiment as shown in Figure 3 backlight 1 be preferably and use LED lamp, LED light fixture that long, low in energy consumption advantage of life-span is arranged, suitablely be applied to provide backlight for television set.
To be applied to be that LED lamp power supply in the television set is an example to the booster circuit as shown in Figure 32 controlled of the overvoltage crowbar that is provided with the utility model embodiment below, more detailed elaboration the technical solution of the utility model:
Suppose that the voltage of voltage input end Vin input is 12V as shown in Figure 4; the normal working voltage of LED lamp is 35-60V; the predetermined protection voltage of LED lamp is 65V; safe voltage on the first resistive module R1 that conversion obtains according to 65V is 1.5V; during television boot-strap; booster circuit 2 work; the 12V voltage that booster circuit 2 is imported voltage input end Vin usually is increased at least more than the 65V and exports the LED lamp to as the initial output voltage of voltage output end Vout and by voltage output end Vout; at this moment; voltage on the first resistive module R1 is if exceed 1.5V (for example being 2.4V); then can 5 pairs of booster circuits of trigger protection module 2 control commands that send the low level forms; thereby control booster circuit 2 quits work; because the existence of the instantaneous division module 4 that the utility model embodiment is provided has reduced the voltage on the first resistive module R1; so during start; the probability of trigger protection module 5 reduces far away; as long as the parameter of instantaneous division module 4 or model are selected suitably; then can make the voltage on the first resistive module R1 not exceed 1.5V fully; thereby guarantee that the LED lamp obtains being enough to support the voltage of its operate as normal; and when entering normal operating conditions after the television boot-strap; the output voltage of voltage output end Vout no longer has been an initial voltage; so instantaneous division module 4 no longer reduces the voltage on the first resistive module R1; if the overvoltage phenomenon appears in this moment, overvoltage crowbar still can operate as normal.
The above; it only is embodiment of the present utility model; but protection range of the present utility model is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; the variation that can expect easily or replacement all should be encompassed within the protection range of the present utility model.Therefore, protection range of the present utility model should be as the criterion with the protection range of claim.
Claims (10)
1. an overvoltage buffer circuit is characterized in that, comprises first resistive module and the instantaneous division module that link to each other with voltage output end, wherein:
Described voltage output end is by the described first resistive module ground connection;
Described instantaneous division module is in parallel with described first resistive module;
Described instantaneous division module when being used for initial output voltage at described voltage output end and exceeding predetermined protection voltage, reduces the voltage on described first resistive module.
2. overvoltage buffer circuit according to claim 1 is characterized in that, this overvoltage buffer circuit also comprises second resistive module, and described second resistive module is electrically connected between described first resistive module and the described voltage output end.
3. overvoltage buffer circuit according to claim 2 is characterized in that, described instantaneous division module at least one electric capacity or described instantaneous division module be two with last capacitances in series and/or be formed in parallel;
And/or, described first resistive module at least one resistance or be two with last resistance string connection and/or be formed in parallel;
And/or, described second resistive module at least one resistance or be two with last resistance string connection and/or be formed in parallel.
4. overvoltage buffer circuit according to claim 2 is characterized in that, the appearance value of described instantaneous division module is between 100nF～1000nF.
5. an overvoltage crowbar is characterized in that, comprises the arbitrary described overvoltage buffer circuit of protection module, test lead, control end and claim 1 to 4, wherein:
Described test lead is electrically connected between described first resistive module and the described voltage output end;
Described protection module links to each other with described test lead and described control end respectively;
Described protection module; be used for surveying voltage on described first resistive module by described test lead; and the voltage on described first resistive module, is controlled described booster circuit and is quit work the booster circuit sending controling instruction by described control end when exceeding predetermined safe voltage.
6. overvoltage crowbar according to claim 5 is characterized in that, described protection module is the overvoltage protection chip, and described overvoltage protection chip comprises comparator and controller, wherein:
Described comparator is used for the voltage on the more described test lead and the size of predetermined safe voltage, and comparative result is imported described controller;
Described controller when being used for voltage on described test lead greater than predetermined safe voltage,, being controlled described booster circuit and is quit work described booster circuit sending controling instruction by described control end.
7. overvoltage crowbar according to claim 5 is characterized in that, described booster circuit is the BOOST booster circuit.
8. overvoltage crowbar according to claim 5; it is characterized in that; this overvoltage buffer circuit; also comprise described second resistive module; described test lead is electrically connected between described first resistive module and described second resistive module; and/or described booster circuit comprises the electrochemical capacitor of inductance, first diode, metal-oxide-semiconductor, voltage input end, described voltage output end and ground connection, wherein:
A wherein end of described inductance links to each other with described voltage input end, and the wherein other end of described inductance links to each other with the drain electrode anodal and described metal-oxide-semiconductor of described first diode respectively;
The negative pole of described first diode links to each other with the anodal and described voltage output end of electrochemical capacitor respectively;
The source electrode of described metal-oxide-semiconductor is electrically connected between described electrochemical capacitor negative pole and the ground;
The grid of described metal-oxide-semiconductor links to each other with described control end.
9. overvoltage crowbar according to claim 8 is characterized in that, described booster circuit also comprises the 3rd resistance, the 4th resistance, the 5th resistance and second diode, wherein:
Described the 3rd resistance links to each other with the grid of described metal-oxide-semiconductor and the source electrode of described metal-oxide-semiconductor respectively;
Described the 4th resistance links to each other with the grid and the described control end of described metal-oxide-semiconductor respectively;
The positive pole of described second diode links to each other with the grid of described metal-oxide-semiconductor, and the negative pole of described second diode links to each other with described control end;
A wherein end of described the 5th resistance links to each other with the source electrode of described metal-oxide-semiconductor and described the 3rd resistance, and the wherein other end of described the 5th resistance is electrically connected between described electrochemical capacitor and the described ground;
And/or described booster circuit also comprises filter capacitor, and described filter capacitor is in parallel with described electrochemical capacitor.
10. a television set is characterized in that, comprises the arbitrary described overvoltage crowbar of backlight, booster circuit and claim 5 to 9, and the described voltage output end of described booster circuit is described backlight power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200198300U CN201946974U (en) | 2011-01-21 | 2011-01-21 | Overvoltage buffer circuit, overvoltage protection circuit and television |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2011200198300U CN201946974U (en) | 2011-01-21 | 2011-01-21 | Overvoltage buffer circuit, overvoltage protection circuit and television |
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| CN201946974U true CN201946974U (en) | 2011-08-24 |
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| CN2011200198300U Expired - Lifetime CN201946974U (en) | 2011-01-21 | 2011-01-21 | Overvoltage buffer circuit, overvoltage protection circuit and television |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103683255A (en) * | 2013-11-28 | 2014-03-26 | 成都市宏山科技有限公司 | Starting-up anti-surge circuit |
| CN108336722A (en) * | 2018-04-11 | 2018-07-27 | 四川升华电源科技有限公司 | Surge restraint circuit in parallel |
-
2011
- 2011-01-21 CN CN2011200198300U patent/CN201946974U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103683255A (en) * | 2013-11-28 | 2014-03-26 | 成都市宏山科技有限公司 | Starting-up anti-surge circuit |
| CN108336722A (en) * | 2018-04-11 | 2018-07-27 | 四川升华电源科技有限公司 | Surge restraint circuit in parallel |
| CN108336722B (en) * | 2018-04-11 | 2024-01-16 | 四川升华电源科技有限公司 | Parallel surge suppression circuit |
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