CN210725077U

CN210725077U - Television anti-burning circuit, device and television

Info

Publication number: CN210725077U
Application number: CN201922491125.XU
Authority: CN
Inventors: 蒋明珠; 于洋
Original assignee: Huizhou Shiwei New Technology Co Ltd
Current assignee: Huizhou Shiwei New Technology Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-06-09
Anticipated expiration: 2029-12-30

Abstract

The utility model relates to a TV set overheat protection technical field especially relates to a TV prevents burning circuit, device and TV set. The television anti-burning circuit comprises: the television comprises an on-off unit, a temperature detection unit and an anti-burning trigger unit, wherein the on-off unit is arranged in a power supply loop of the television, a controlled end of the on-off unit is connected with a first control end of the anti-burning trigger unit, and the temperature detection unit is arranged in a rear shell of the television; the on-off unit is used for disconnecting the power supply loop when the controlled end receives a high-level signal; the temperature detection unit is used for generating a voltage signal corresponding to the internal temperature in the rear shell of the television and outputting the voltage signal to the anti-burning triggering unit; and the burning prevention triggering unit is used for sending a high-level signal to the controlled end of the on-off unit through the first control end when the voltage signal is less than the preset safe voltage so as to enable the on-off unit to disconnect the power supply loop. The circuit prevents the television from being overheated and ignited, and ensures the use safety of the television.

Description

Television anti-burning circuit, device and television

Technical Field

The utility model relates to a TV set overheat protection technical field especially relates to a TV prevents burning circuit, device and TV set.

Background

The LCD TV comprises an LCD panel and a back shell, wherein the back shell comprises: a power circuit board, a television main board, a TCON board (Timing Controller logic board, screen driving board), and the like; a plurality of heat dissipation holes are formed in the edge of the rear shell; the heat dissipation holes can be used for heat dissipation when the television normally works. However, when the television fails, the temperature in the rear shell rises sharply, the heat dissipation holes cannot meet the heat dissipation requirement, combustion can be caused, and if the external circuit cannot be disconnected in time at the moment, fire can be caused in serious cases. How to prevent the television from catching fire under extreme conditions becomes a safety problem which needs to be solved urgently.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a main aim at provides TV prevents burning circuit, device and TV set, overheated burning when aiming at preventing TV set circuit trouble.

In order to achieve the above object, the utility model provides a TV prevents burning circuit, TV prevents burning circuit includes: the television comprises an on-off unit, a temperature detection unit and an anti-burning trigger unit, wherein the on-off unit is arranged in a power supply loop of a television, a controlled end of the on-off unit is connected with a first control end of the anti-burning trigger unit, and the temperature detection unit is arranged in a rear shell of the television; wherein,

the on-off unit is used for disconnecting the power supply loop when the controlled end receives a high level signal;

the temperature detection unit is used for generating a voltage signal corresponding to the internal temperature in the rear shell of the television and outputting the voltage signal to the burning prevention triggering unit;

the anti-burning triggering unit is used for sending a high-level signal to the controlled end of the on-off unit through the first control end when the voltage signal is smaller than a preset safe voltage, so that the on-off unit breaks off the power supply loop.

Optionally, the power supply circuit includes a power board and a main board; wherein,

the power panel is used for receiving the electric energy output by the television power interface and outputting the electric energy to the circuit of the television;

the first connecting end of the on-off unit is connected with the first output end of the television power interface;

the second connecting end of the on-off unit is connected with the first connecting end of the power panel, and the second connecting end of the power panel is connected with the second output end of the television power interface;

the output end of the power panel is connected with the input end of the mainboard.

Optionally, the power supply circuit further comprises a logic board;

the burning-prevention trigger unit is further used for generating a driving cut-off signal when the voltage signal is smaller than a preset safe voltage, and outputting the driving cut-off signal to the mainboard through a second control end;

and the main board is also used for stopping outputting data to the logic board when the controlled end receives the driving cut-off signal.

Optionally, the output end of the main board is connected to the input end of the logic board, and the controlled end of the main board is connected to the second control end of the burn-proof trigger unit.

Optionally, the burning prevention triggering unit includes a comparison subunit, a conversion subunit, and a rectifier subunit; wherein,

the comparison subunit is configured to receive the voltage signal, compare the voltage signal with a preset safe voltage, and output a low level signal to the conversion subunit when the current voltage is lower than the preset safe voltage;

the conversion subunit is configured to receive the low level signal, convert the low level signal into a high level signal, and output the high level signal to the rectification subunit;

and the rectifier subunit is used for receiving and rectifying the high level signal and sending the rectified high level signal to the on-off unit so as to enable the on-off unit to disconnect the power supply loop.

Optionally, a first input end of the comparison subunit is connected to an output end of the temperature detection unit, a second input end of the comparison subunit is connected to a reference voltage end for outputting a preset safe voltage, and an output end of the comparison subunit is connected to an input end of the conversion subunit;

the first control end of the conversion subunit is connected with the controlled end of the rectifier subunit, and the second control end of the conversion subunit is connected with the controlled end of the main board;

and the output end of the rectifier subunit is connected with the controlled end of the on-off unit.

Optionally, the rectifier sub-unit includes a transformer and a rectifier module; wherein,

the primary end of the transformer is connected with the first control end of the converting subunit, and the secondary end of the transformer is connected with the input end of the rectifying module;

the transformer is used for receiving the high level signal and outputting the received high level signal to the rectifying module;

the rectification module is used for rectifying the high level signal and sending the rectified high level signal to the on-off unit so that the on-off unit can disconnect the power supply loop.

Optionally, the rectifier module comprises: the circuit comprises a first resistor, a second resistor, a first capacitor, a second capacitor and a diode; wherein,

the first pin and the second pin of the transformer are secondary ends, and the third pin and the fourth pin of the transformer are primary ends;

the rectifier module further comprises a first node, a second node, a third node, a fourth node, a fifth node and a sixth node; the first node is connected with the second node, and the second node is connected with the third node; the fourth node is connected with the fifth node;

the first end of the first resistor is connected with a first node, the first node is grounded, the first end of the first capacitor is connected with a second node, and the first end of the second capacitor and the first pin of the transformer are connected with a third node;

the second end of the first resistor and the controlled end of the on-off unit are connected with a fourth node, the second end of the first capacitor, the first end of the second resistor and a fifth node are connected, and the second end of the second resistor, the second end of the second capacitor and the cathode of the diode are connected with a sixth node;

the second pin of the transformer is connected with the anode of the diode, the third pin of the transformer is connected with the first control end of the conversion subunit, and the fourth pin of the transformer is grounded.

In addition, in order to achieve the above object, the present invention further provides a television burn-proof device, which comprises the television burn-proof circuit as described above.

In addition, in order to achieve the above object, the present invention further provides a television set, which comprises the television anti-burning circuit as described above.

The utility model discloses a set up TV and prevent burning circuit, TV prevents burning circuit includes: the television comprises an on-off unit, a temperature detection unit and an anti-burning trigger unit, wherein the on-off unit is arranged in a power supply loop of a television, a controlled end of the on-off unit is connected with a first control end of the anti-burning trigger unit, and the temperature detection unit is arranged in a rear shell of the television; the on-off unit is used for disconnecting the power supply loop when the controlled end receives a high-level signal; the temperature detection unit is used for generating a voltage signal corresponding to the internal temperature in the rear shell of the television and outputting the voltage signal to the burning prevention triggering unit; the anti-burning triggering unit is used for sending a high-level signal to the controlled end of the on-off unit through the first control end when the voltage signal is smaller than a preset safe voltage, so that the on-off unit breaks off the power supply loop. Whether the temperature in the television rear shell is within the preset safe temperature or not is detected, and when the internal temperature is higher than the preset safe temperature, the anti-burning triggering unit disconnects the passage between the external input circuit and the internal circuit of the television, so that the television is prevented from being overheated and ignited, and the safety of television devices and the use safety of users are guaranteed.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a block diagram of a first embodiment of a tv burn-proof circuit according to the present invention;

FIG. 2 is a block diagram of a second embodiment of the TV burn-proof circuit of the present invention

Fig. 3 is a schematic circuit diagram of a second embodiment of the tv burn-proof circuit of the present invention.

The reference numbers illustrate:

the objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, it should be considered that the combination of the technical solutions does not exist, and is not within the protection scope of the present invention.

The embodiment of the utility model provides a TV prevents burning circuit, refer to fig. 1, fig. 1 is the utility model discloses TV prevents burning circuit's the structural block diagram of the first embodiment. The television set comprises an on-off unit 100, a temperature detection unit 200 and a burning prevention trigger unit 300, wherein the on-off unit 100 is arranged in a power supply loop 400 of the television set, a controlled end of the on-off unit 100 is connected with a first control end of the burning prevention trigger unit 300, and the temperature detection unit 200 is arranged in a rear shell of the television set.

The on-off unit 100 is configured to turn off the power supply circuit 400 when the controlled terminal receives a high level signal.

It should be noted that the on-off unit 100 may be an electrical switch capable of receiving electrical signal control, such as a fuse control module, an electromagnetic switch, and a relay; the main function of the switching unit 100 is to switch off the controlled terminal in an emergency when receiving a high signal, so that the power supply circuit 400 is switched off in an emergency.

It is easy to understand that the power supply circuit 400 is a working circuit of the television, the power supply circuit 400 is used for supplying power to working modules of the television, the power supply circuit includes working modules of the television, such as a power board, a television main board, a logic board (for example, a TCON board), and the like, a first input end of the power board is connected to the on-off unit 100, and a second input end of the power board is connected to a second output end of the television power interface J1. The first output end of the television power interface J1 is connected to the on-off unit 100, and the television power interface outputs 220V alternating current for the television to work normally. The power panel is connected with the mainboard and supplies power to the mainboard; the main board is connected with the logic board and provides television picture signals which work normally.

It should be noted that the first pin of the television power interface J1 is the first output end, the second pin of the television power interface J1 is floating, and the third pin of the television power interface J1 is the second output end.

The temperature detection unit 200 is configured to generate a voltage signal corresponding to an internal temperature of the rear housing of the television, and output the voltage signal to the burn-proof trigger unit 300.

The temperature detecting unit 200 is a thermistor or a temperature sensor, and when the temperature rises, the resistance of the thermistor decreases with the rise of the temperature, that is, the higher the temperature is, the lower the voltage division of the thermistor is, the lower the current voltage corresponding to the thermistor is.

The burning prevention triggering unit 300 is configured to send a high level signal to the controlled end of the on-off unit 100 through the first control end when the voltage signal is less than a preset safe voltage, so that the on-off unit 100 disconnects the power supply loop 400.

It should be noted that the burning-prevention triggering unit includes a comparison subunit, a conversion subunit and a rectification subunit; the comparison subunit is configured to receive the current voltage, compare the current voltage with the preset safe voltage, and output a low-level signal to the conversion subunit when the current voltage is smaller than the preset safe voltage; and the conversion subunit is used for receiving the low level signal, converting the low level signal into a high level signal and outputting the high level signal to the input end of the rectification subunit.

It should be noted that the comparing subunit and the converting subunit may be a micro control unit, the micro control unit may be a single chip, and an input end of the comparing subunit is connected to the reference voltage end and an output end of the temperature detecting unit 200, respectively, so as to compare the current voltage with the reference voltage. The temperature detection unit 200 outputs a lower induced voltage as the temperature is higher. In a specific implementation, the sensing unit 200 may be a temperature sensitive resistor or a temperature sensor. The reference voltage is a preset safe voltage, and the preset safe voltage is a voltage corresponding to the highest threshold value of the safe working temperature of the television. In specific implementation, a direct current battery can be arranged in the television to provide the preset safe voltage; or a voltage dividing resistor is arranged for dividing voltage, the divided voltage of the voltage dividing resistor does not change along with the temperature, and the comparison subunit compares the divided voltage with a voltage signal output by the output end of the temperature detection unit 200. When the temperature in the television rear shell exceeds the highest threshold of the safe working temperature, the induced voltage output by the temperature detection unit 200 drops sharply and is lower than the preset safe voltage, the comparison subunit outputs a low level signal, the conversion subunit converts the low level signal into a high level signal, and a large current is output through the rectification subunit to trigger the on-off unit 100 to be switched off so as to protect the power supply loop 400.

It is easy to understand that, when the television is used, the conditions of component aging, failure of individual components, external attack and the like occur, although the events are small probability, once the events occur, the circuit is short-circuited, the temperature in the rear shell rises rapidly, and a fire disaster is caused in serious cases. The opening of the on-off unit 100 causes the path between the external circuit and the internal circuit of the television to be opened, preventing the external power supply from continuing to supply heat to the television and the circuits in the television from further heating.

It is easy to understand that, because there are differences of models and powers in the televisions, the safe operating temperatures of different televisions are different, and the preset safe voltage corresponding to the safe operating temperature can be set according to the actual requirements of the televisions.

The circuit of the embodiment cuts off a path between the external input circuit and the internal circuit of the television through the anti-burning triggering unit when the internal temperature is higher than the preset safe temperature by detecting whether the temperature in the rear shell of the television is in the preset safe temperature, so that the television is protected from overheating and firing, and the safety of television devices and the use safety of users are guaranteed.

Based on the first embodiment of the tv burn-proof circuit of the present invention, a second embodiment of the tv burn-proof circuit of the present invention is proposed, referring to fig. 2 and 3, fig. 2 is a block diagram of the second embodiment of the tv burn-proof circuit of the present invention; fig. 3 is a schematic circuit diagram of a second embodiment of the tv burn-proof circuit of the present invention.

The power supply circuit 400 includes a power board 401 and a motherboard 402. The first connection end of the on-off unit 100 is connected with the first output end of the television power interface J1, and the controlled end of the on-off unit 100 is connected with the first control end of the anti-burning triggering unit 300; a second connecting end of the on-off unit 100 is connected with a first input end of the power panel 401, and a second input end of the power panel 401 is connected with a second output end of the television power interface J1; the output end of the power panel 401 is connected with the input end of the main board 402.

The power supply circuit 400 further includes a logic board 403, an output end of the main board 402 is connected to an input end of the logic board 403, and a controlled end of the main board 402 is connected to the second control end of the burn-prevention trigger unit 300.

It should be noted that the power board 401 receives 220V ac power from the output terminal of the television power interface J1, and supplies the ac power to the main board 402. The main board of the television is connected with the logic board of the television and provides television picture signals which work normally.

It should be noted that the burning prevention triggering unit 300 is further configured to generate a driving cutoff signal when the voltage signal is smaller than a preset safe voltage, and output the driving cutoff signal to the main board 402; the main board 402 is further configured to receive the driving off signal and stop outputting data to the logic board 403.

It is easy to understand that the on-off unit 100 in the first embodiment disconnects the path between the external power source and the internal circuit, but the operation of the internal circuit has a delay, so as to further protect the internal circuit of the television, the output data of the main board 402 should be reduced to zero; that is, the burn-in prevention trigger unit 300 generates a drive off signal, and the main board 402 receives the drive off signal and forcibly zeroes the drive data to output the drive data in order to protect the following logic board and liquid crystal panel. The signal input to logic board 403 is turned off and all the received data is zero, which corresponds to the input source being turned off.

The burning-prevention trigger unit 300 comprises a comparison subunit 301, a conversion subunit 302 and a rectifier subunit 303; wherein,

a first input end of the comparison subunit 301 is connected to an output end of the temperature detection unit 200, a second input end of the comparison subunit 301 is connected to a reference voltage end V, and the reference voltage end V is used for outputting a preset safety voltage.

It is easy to understand that the temperature sensed by the temperature detecting unit 200 is higher, the sensed voltage is lower, the preset safety voltage is the voltage threshold value sensed by the temperature detecting unit 200 when the television operates in the preset safety temperature, and when the voltage sensed by the temperature detecting unit 200 is lower than the preset safety voltage, it indicates that the television temperature is higher than the preset safety temperature, and the anti-burning protection is required. Because there are the difference of model and power in the TV, the safe operating temperature of different TVs is different, and the safe voltage of predetermineeing that safe operating temperature corresponds can set up according to TV set actual demand. In specific implementation, a direct current battery can be arranged in the television to provide the preset safe voltage; or a voltage division resistor is arranged for voltage division, the voltage division of the voltage division resistor does not change along with the temperature, and further, the setting can be carried out through a micro control unit. The comparison subunit 301 compares the divided voltage with the voltage signal output by the output terminal of the temperature detection unit 200. The output end of the comparison subunit 301 is connected with the input end of the conversion subunit 302; the first control end of the converting subunit 302 is connected to the controlled end of the rectifying subunit 303, and the second control end of the converting subunit 302 is connected to the controlled end of the main board 402; the output end of the rectifier subunit 303 is connected with the controlled end of the on-off unit 100.

It should be noted that the comparison subunit 301 includes a voltage comparator U1, the non-inverting terminal of the voltage comparator U1 is connected to the output terminal of the temperature detection unit 200, and the inverting terminal of the voltage comparator U1 is connected to the reference voltage terminal V.

It should be noted that the comparing subunit 301 is configured to receive the voltage signal, compare the voltage signal with the preset safe voltage, and output a low level signal to the converting subunit 302 when the current voltage is less than the preset safe voltage; the converting subunit 302 is configured to receive the low level signal, convert the low level signal into a high level signal, and output the high level signal to the rectifying subunit 303. The rectifier subunit 303 is configured to receive and rectify the high level signal, and send the rectified high level signal to the on-off unit 100, so that the on-off unit 100 disconnects the power supply loop 400.

It is easy to understand that the comparing subunit 301 and the converting subunit 302 can be integrated into a micro control unit, which can be a single chip. The comparison subunit 301 may be replaced by another component besides the voltage comparator U1, and the voltage comparator is taken as an example in this embodiment.

The rectifying subunit 303 includes a transformer T1 and a rectifying module 304; wherein the primary terminal of the transformer T1 is connected to the first control terminal of the converting subunit 302, and the secondary terminal of the transformer T1 is connected to the input terminal of the rectifying subunit 302; the transformer T1 receives the high level signal and outputs the high level signal to the rectifying module 304; the rectifying module 304 is configured to rectify the high level signal and send the rectified high level signal to the on-off unit 100, so that the on-off unit 100 disconnects the power supply loop 400.

It should be noted that, in an implementation manner, the transformer T1 may be an isolation transformer, for example, a conversion ratio of the isolation transformer may be 1: 1, the isolation transformer isolates the primary side from the secondary side, provides safe current output, and has anti-jamming function.

The rectification module 304 includes: the circuit comprises a first resistor R1, a second resistor R2, a first capacitor C1, a second capacitor C2 and a diode D1; the first pin and the second pin of the transformer T1 are secondary terminals, and the third pin and the fourth pin of the transformer T1 are primary terminals; the rectifying module 304 further includes a first node 1, a second node 2, a third node 3, a fourth node 4, a fifth node 5, and a sixth node 6; the first node 1 is connected with the second node 2, and the second node 2 is connected with the third node 3; the fourth node 4 is connected with the fifth node 5; a first end of the first resistor R1 is connected to a first node 1, the first node 1 is grounded, a first end of the first capacitor C1 is connected to a second node 2, and a first end of the second capacitor C2 and a first pin of the transformer T1 are connected to a third node 3; a second end of the first resistor R1 and a controlled end of the on-off unit 100 are connected to a fourth node 4, a second end of the first capacitor C1 and a first end of the second resistor R2 are connected to a fifth node 5, and a second end of the second resistor R2, a second end of the second capacitor C2 and a cathode of the diode D1 are connected to a sixth node 6; the second pin of the transformer T1 is connected to the anode of the diode D1, the third pin of the transformer T1 is connected to the first control terminal of the converting subunit 302, and the fourth pin of the transformer T1 is grounded.

It should be noted that, when the transformer T1 receives a high level signal input from the converting subunit 302, and after isolation, the rectifying module 304 converts the high level signal into a large current, and outputs the large current to the on-off unit 100, so as to trigger the on-off unit 100 to disconnect the external power supply and the internal circuit.

It is easy to understand that the burn-proof trigger unit 300 controls the on-off unit 100 to be turned off, and controls the main board 402 in the power supply circuit 400 to change the driving data to zero and output, so as to protect the working circuit of the television from the outside and the inside.

The embodiment of the utility model provides a through when inside temperature surpasses safe operating temperature, disconnection TV inner circuit and external power source's route, the output data of TV mainboard becomes zero output simultaneously, has protected the logic board and the liquid crystal display panel of TV, prevents that the inner circuit of TV from damaging because overheated, has protected the components and parts safety of TV, has protected user's safety in utilization.

Furthermore, for realizing above-mentioned purpose, the utility model discloses still provide a TV and prevent burning device, because this TV prevents burning device has adopted the whole technical scheme of above-mentioned all embodiments, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, no longer gives unnecessary detail here.

Furthermore, in order to achieve the above object, the utility model discloses still provide a television, because this television has adopted the whole technical scheme of above-mentioned all embodiments, consequently have all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, no longer give unnecessary details here.

It should be understood that the above is only an example, and the technical solution of the present invention is not limited in any way, and in the specific application, those skilled in the art can set the solution as required, and the present invention is not limited thereto.

It should be noted that the above-described work flow is only illustrative, and does not limit the scope of the present invention, and in practical applications, a person skilled in the art may select some or all of them to achieve the purpose of the solution of the embodiment according to practical needs, and the present invention is not limited herein.

Further, it is to be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.

The above embodiment numbers of the present invention are only for description, and do not represent the advantages and disadvantages of the embodiments.

The above is only the preferred embodiment of the present invention, and not the scope of the present invention, all the equivalent structures or equivalent flow changes made by the contents of the specification and the drawings or the direct or indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A television burn-in prevention circuit, the television burn-in prevention circuit comprising: the television comprises an on-off unit, a temperature detection unit and an anti-burning trigger unit, wherein the on-off unit is arranged in a power supply loop of a television, a controlled end of the on-off unit is connected with a first control end of the anti-burning trigger unit, and the temperature detection unit is arranged in a rear shell of the television; wherein,

2. The television burn-proof circuit of claim 1, wherein the power supply loop comprises a power board and a main board; wherein,

3. The television burn prevention circuit of claim 2 wherein said power supply loop further comprises a logic board;

4. The tv burn-in prevention circuit of claim 3, wherein the output terminal of the main board is connected to the input terminal of the logic board, and the controlled terminal of the main board is connected to the second control terminal of the burn-in prevention trigger unit.

5. The TV burn-proof circuit as claimed in claim 4, wherein the burn-proof trigger unit comprises a comparison subunit, a conversion subunit and a rectification subunit; wherein,

6. The tv burn-proof circuit as claimed in claim 5, wherein a first input terminal of the comparing subunit is connected to an output terminal of the temperature detecting unit, a second input terminal of the comparing subunit is connected to a reference voltage terminal for outputting a preset safety voltage, and an output terminal of the comparing subunit is connected to an input terminal of the converting subunit;

7. The tv burn prevention circuit of claim 6 wherein said rectifier sub-unit comprises a transformer and a rectifier module; wherein,

the transformer is used for receiving the high level signal and outputting the high level signal to the rectifying module;

8. The television burn prevention circuit of claim 7 wherein said rectifying module comprises: the circuit comprises a first resistor, a second resistor, a first capacitor, a second capacitor and a diode; wherein,

9. A television burn-proof device, characterized in that the device comprises a television burn-proof circuit according to any one of claims 1 to 8.

10. A television set, characterized in that the television set comprises the television burn-proof circuit as claimed in any one of claims 1 to 8.