Power supply circuit, integrated circuit board and display device

Abstract

The utility model provides a power supply circuit, an integrated circuit board and a display device. The power supply circuit comprises a transformer isolation circuit and an over-temperature protection circuit. The transformer isolation circuit comprises an input module, a transformer and a plurality of output modules. The over-temperature protection circuit comprises a switch module and a temperature detection module. The first end of the switch module is grounded, and the second end of the switch module is connected with the second end of the input module; the input end of the temperature detection module is connected with a plurality of secondary windings of the transformer and used for sampling the current temperature of the transformer and adjusting the output voltage of the temperature detection module according to sampling information, and the output end of the temperature detection module is connected with the controlled end of the switch module so as to control the on-off of the switch module according to different output voltages. The over-temperature protection circuit can sample the temperature of the transformer isolation circuit in real time and control the working state of the transformer isolation circuit according to the temperature, so that the problem that the transformer isolation circuit cannot be normally used due to the fact that the temperature is too high is solved, and the over-temperature protection function is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of output power protection, and more specifically, to a power supply circuit, an integrated circuit board and a display device. Background Art

[0002] An isolation transformer is generally provided in the power supply circuit to isolate the respective circuits of the original secondary windings, so as to ensure the stability of the output voltage provided by the power supply circuit to the output load. At present, the power supply circuit is usually provided with multiple output loads. At this time, the isolation transformer is set to a structure of one input to multiple outputs to provide corresponding output voltages for different output loads. However, when only one of the multiple output loads corresponding to the isolation transformer is loaded and the other output loads are unloaded, the output current of the secondary winding corresponding to the loaded output load in the isolation transformer is too large, causing the isolation transformer to heat up and affect the isolation effect of the isolation transformer. In addition, it is currently necessary to control the temperature of the isolation transformer to determine whether the isolation transformer meets the safety certification. When it is detected that the temperature of the isolation transformer reaches about 150°C (degrees Celsius), the isolation transformer does not meet the safety certification and cannot be used normally.

[0003] At present, the related technology usually reduces the power overcurrent point of the isolation transformer, which will lead to a reduction in the load carrying capacity. Therefore, how to ensure the reliability of the transformer isolation circuit without reducing the load carrying capacity has become an urgent problem to be solved. Utility Model Content

[0004] To solve the above problems, the present application provides a power supply circuit, an integrated circuit board and a display device. The over-temperature protection circuit can sample the temperature of the transformer isolation circuit in real time and control the working state of the transformer isolation circuit according to the temperature, that is, the transformer isolation circuit can stop working when the temperature is too high, thereby avoiding the problem that the transformer isolation circuit cannot be used normally due to excessive temperature, and ensuring the isolation and reliability of the transformer isolation circuit.

[0005] In the first aspect, the present application provides a power supply circuit, including a transformer isolation circuit and an over-temperature protection circuit; the transformer isolation circuit includes an input module, a transformer and multiple output modules, the first end of the input module is connected to the primary winding of the transformer, and the multiple secondary windings of the transformer are connected to the multiple output modules one by one; the over-temperature protection circuit includes a switch module and a temperature detection module; the first end of the switch module is grounded, and the second end of the switch module is connected to the second end of the input module; the input end of the temperature detection module is connected to the multiple secondary windings of the transformer, and is used to sample the current temperature of the transformer, and adjust the output voltage of the temperature detection module according to the sampling information, and the output end is connected to the controlled end of the switch module to control the on and off of the switch module according to the different output voltages of the temperature detection module. If the switch module is turned on, the input module stops working; if the switch module is turned off, the input module starts working.

[0006] The power supply circuit provided based on the embodiment of the present application can sample the temperature of the transformer in real time through the temperature detection module, and output different output voltages corresponding to the detected different temperatures to control the on-off of the switch module, thereby realizing the control of the working state of the input module to realize the function of over-temperature protection. In this way, the working state of the input module is controlled by the temperature information sampled in real time by the temperature detection module, thereby avoiding the problem that the transformer temperature is too high and cannot be used normally, and ensuring the reliability of the transformer isolation circuit. Moreover, the temperature detection module in the present application can control the working state of the input module based on the temperature information, without setting up an additional control chip and a detection circuit to process the temperature information, saving the production cost and avoiding the problem of information interference caused by a long detection circuit.

[0007] In combination with the first aspect, in some possible implementations, the temperature detection module includes: a thermistor and a voltage divider unit; one end of the thermistor is connected to the output end of the transformer and the input ends of multiple output modules, and is used to sample the current temperature of the transformer, and adjust the resistance value of the thermistor according to the sampling information to adjust the size of the output voltage of the thermistor; the voltage divider unit, one end of which is connected to the other end of the thermistor and the controlled end of the switch module, and is used to divide the output voltage of the thermistor to obtain a divided voltage, and the other end is grounded; when the current temperature sampled by the thermistor is less than or equal to the preset temperature, the divided voltage after the voltage divider unit is divided is less than the on-voltage of the switch module, the switch module is turned off, and the input module starts working; when the current temperature sampled by the thermistor is greater than the preset temperature, the divided voltage after the voltage divider unit is divided is greater than the on-voltage, and the input module stops working.

[0008] In the above technical scheme, the thermistor has a high sensitivity. The present application samples the current temperature of the transformer through the thermistor to ensure the reliability and accuracy of the sampling. At the same time, the voltage corresponding to the preset temperature is set as the on-voltage of the switch module, and the output voltage of the voltage divider unit is divided by the voltage divider unit to obtain the divided voltage, so that the over-temperature protection circuit can control the on and off of the switch module based on the divided voltage to achieve control of the input module. There is no need to set up additional control chips and detection circuits to process temperature information, which saves production costs and avoids the problem of information interference caused by a long detection circuit.

[0009] In combination with the first aspect, in some possible implementations, the over-temperature protection circuit also includes a rectifier module, one end of the rectifier module is connected to the other end of the thermistor, and the other end is connected to one end of the voltage divider unit, for rectifying the output voltage of the thermistor.

[0010] In combination with the first aspect, in some possible implementations, the rectifier module includes a first diode, one end of the first diode is connected to the other end of the thermistor, and the other end is connected to one end of the voltage divider unit, for rectifying the output voltage of the thermistor.

[0011] In combination with the first aspect, in some possible implementations, the over-temperature protection circuit also includes a filtering unit, one end of the filtering unit is connected to the other end of the thermistor and the controlled end of the switch module, and the other end is grounded, for filtering the divided voltage.

[0012] In combination with the first aspect, in some possible implementations, the switch module includes an NMOS, a source is grounded, a drain is connected to the second end of the input module, and a gate is connected to the output end of the temperature detection module.

[0013] In combination with the first aspect, in some possible implementations, the power supply circuit also includes a control module; the first end of the control module is connected to the second end of the switch module, the second end is connected to the second end of the input module, and the third end is grounded, and is used to control the working state of the input module according to the on and off state of the switch module.

[0014] In the above technical solution, the over-temperature protection circuit realizes the control module of the input module by controlling the on and off of the switch module. There is no need to set up additional control chips and detection circuits to process temperature information, which saves production costs and avoids the problem of information interference caused by a long detection circuit.

[0015] In combination with the first aspect, in some possible implementations, the control module includes an optocoupler and a Zener diode; the first end of the optocoupler is connected to the power supply voltage, the second end of the optocoupler is respectively connected to the second end of the switch module and one end of the Zener diode, the third end and the fourth end of the optocoupler are respectively connected to the second end of the input module, the other end of the Zener diode is grounded, and the Zener diode is used to provide a reference voltage; when the switch module is turned on, the reference voltage of the Zener diode drops, and the control module controls the input module to stop working; when the switch module is turned off, the reference voltage of the Zener diode remains unchanged, and the control module controls the input module to start working.

[0016] In a second aspect, the present application provides an integrated circuit board, comprising a circuit board body and a power supply circuit as described in any optional manner of the first aspect, wherein the power supply circuit is arranged on the circuit board body.

[0017] In a third aspect, the present application provides a display device, comprising a display panel and a power supply circuit as described in any optional manner of the first aspect, the display panel comprising a backlight circuit and a display system, and a plurality of output modules are respectively used to connect to the backlight circuit and the display system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a framework structure of a power transformer provided in an embodiment of the present application;

[0019] Figure 2 It is a schematic diagram of a framework structure of a power supply circuit provided in an embodiment of the present application;

[0020] Figure 3 is a circuit structure diagram of a power supply circuit provided in an embodiment of the present application;

[0021] Figure 4 is a circuit structure diagram of another power supply circuit provided in an embodiment of the present application;

[0022] Figure 5 is a circuit structure schematic diagram of another power supply circuit provided in an embodiment of the present application;

[0023] Figure 6 is a circuit structure diagram of another power supply circuit provided in an embodiment of the present application;

[0024] Figure 7 is a circuit structure diagram of another power supply circuit provided in an embodiment of the present application;

[0025] Figure 8 is a circuit structure diagram of another power supply circuit provided in an embodiment of the present application;

[0026] Fig. 9 is a circuit structure diagram of another power supply circuit provided in an embodiment of the present application;

[0027] Fig.10 is a circuit structure diagram of another power supply circuit provided in an embodiment of the present application;

[0028] Fig.11 It is a schematic diagram of the circuit structure of a display device provided in an embodiment of the present application.

[0029] 1. Power supply circuit; 11. Transformer isolation circuit; 111. Input module; 112. Transformer; 112A. Primary winding; 112B. Secondary winding; 113. Output module; 114; 115; 12. Over-temperature protection circuit; 121. Switch module; 122. Temperature detection module; 1221. Voltage divider unit; 123. Rectifier module; 124. Filter unit; 2. Display panel; 21. Backlight circuit; 22. Display system;

[0030] R1, thermistor; R2, voltage divider resistor; D1, first diode; D2, voltage regulator diode; OC, optocoupler. DETAILED DESCRIPTION

[0031] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, and circuits are omitted to prevent unnecessary details from obstructing the description of the present application.

[0032] Display devices such as televisions and smart tablets are usually equipped with a power supply circuit to supply power to the load (i.e., the display panel). An isolation transformer is generally provided in the power supply circuit to isolate the circuits of the primary and secondary windings to ensure the stability of the output voltage provided by the power supply circuit to the output load. When the power supply circuit corresponds to multiple output loads, the isolation transformer at this time has a structure of one input to multiple outputs to provide corresponding output voltages for different output loads.

[0033] However, when only one of the multiple output loads corresponding to the isolation transformer is loaded and the other output loads are unloaded, the output current of the secondary winding corresponding to the output load in the isolation transformer is too large, which will cause the isolation transformer to heat up, thereby affecting the isolation effect of the isolation transformer. In addition, it is currently necessary to control the temperature of the isolation transformer to determine whether the isolation transformer meets the safety certification. When the temperature of the isolation transformer is detected to reach about 150℃ (Celsius), the isolation transformer does not meet the safety certification and cannot be used normally.

[0034] There are usually two solutions in the related art. One is to reduce the power overcurrent point of the isolation transformer, so as to avoid the problem of the isolation transformer heating caused by excessive output current. However, this will reduce the load carrying capacity and the power supply effect of the power supply circuit, resulting in the display device using the power supply circuit having a poor startup problem, which affects the normal use of the display device. The other is to set a temperature detection chip, the corresponding pin of which is connected to the isolation transformer, for collecting the temperature of the isolation transformer, and then the temperature is compared by the program set in the temperature detection chip to determine whether the temperature is normal, and then the judgment result is fed back to the circuit connected to the primary winding through the isolation transformer. Or a thermistor is connected in series between the temperature detection chip and the isolation transformer, and the temperature of the isolation transformer is collected by the thermistor, and the collected temperature information is sent to the temperature detection chip, so that the temperature detection chip can judge whether the temperature isolation transformer is at normal temperature according to the temperature information. In this way, when the temperature detection chip is used for detection and feedback, the detection loop is long, the detection information is easily interfered and the design cost is high.

[0035] To this end, the embodiments of the present application provide a power supply circuit, an integrated circuit board and a display device. Compared with the over-temperature protection in the related art, the over-temperature protection circuit in the power supply circuit can sample the temperature of the transformer isolation circuit in real time, and directly control the working state of the transformer isolation circuit according to the temperature, thereby avoiding the problem that the transformer isolation circuit cannot be used normally due to excessive temperature. The over-temperature protection circuit can ensure the isolation and reliability of the transformer isolation circuit while providing over-temperature protection for the transformer isolation circuit.

[0036] The power supply circuit, integrated circuit board and display device provided in the present application are exemplarily introduced below in conjunction with the accompanying drawings.

[0037] The embodiment of the present application provides a power supply circuit, which can be used in display devices such as televisions and smart tablets. The power supply circuit can provide a stable voltage for multiple loads in the display device to ensure the display reliability of the display device. The power supply circuit can also be used in other devices, and this application does not make specific restrictions on this.

[0038] In one example, an embodiment of the present application provides a power supply circuit 1, such as Figure 1As shown, the power supply circuit 1 may include a transformer isolation circuit 11, and the transformer isolation circuit 11 may include an input module 111, a transformer 112 and multiple output modules 113, wherein the transformer 112 has a primary winding 112A and multiple secondary windings 112B, the first end of the input module 111 is connected to the primary winding 112A, and the multiple secondary windings 112B of the transformer 112 are respectively connected to the multiple output modules 113 one by one, and the transformer 112 can provide corresponding stable voltages to different output loads through the secondary winding 112B.

[0039] Here, it is worth mentioning that Figure 1 The description is only carried out by taking the setting of two secondary windings 112B and two output modules 113 as an example. The number of secondary windings 112B and output modules 113 can be set according to actual needs, and this application does not make any specific restrictions on this.

[0040] In order to avoid the problem that, in the actual use of the power supply circuit 1, when only one of the multiple output modules 113 is loaded and the other output modules are unloaded, the output current of the secondary winding 112B corresponding to the loaded output load in the transformer isolation circuit 11 is too large, causing the transformer 112 to heat up, thereby affecting the reliability of the transformer isolation circuit 11. In one example, Figure 2 As shown, the power supply circuit 1 provided in the embodiment of the present application may also include an over-temperature protection circuit 12 to sample the temperature information of the transformer 112 in real time, and control the working state of the transformer isolation circuit 11 accordingly according to the detection result, so as to avoid overheating of the transformer 112 and affect the reliability of the use of the transformer isolation circuit 11.

[0041] Optional, such as Figure 3As shown, the over-temperature protection circuit 12 provided in the embodiment of the present application may include a switch module 121 and a temperature detection module 122, the input end of the temperature detection module 122 is connected to the multiple secondary windings 112B of the transformer 112, the output end of the temperature detection module 122 is connected to the controlled end of the switch module 121, the first end of the switch module 121 is grounded, and the second end of the switch module 121 is connected to the second end of the input module 11. The temperature detection module 122 can sample the current temperature of the transformer 112, and adjust the output voltage of the temperature detection module 122 according to the sampled temperature information, so as to control the on and off of the switch module 121 according to different output voltages, thereby realizing the control of the working state of the input module 111, that is, when the temperature of the transformer 112 is too high, the input module 111 is controlled to stop working, thereby reducing the temperature of the transformer 112. For example, if the switch module 121 is turned on, the input module 111 stops working, and the transformer 112 is in a heat dissipation mode at this time; if the switch module 121 is turned off, the input module starts working, and the transformer 112 is in a working mode and does not need heat dissipation.

[0042] The embodiment of the present application can sample the temperature of the transformer 112 in real time through the temperature detection module 122, and output different output voltages corresponding to different detected temperatures to control the on and off of the switch module 121, thereby realizing the control of the working state of the input module 111 to realize the function of over-temperature protection. In this way, the working state of the input module 111 is controlled by the temperature information sampled in real time by the temperature detection module 122, thereby avoiding the problem that the transformer 112 cannot be used normally due to excessive temperature, and ensuring the reliability of the transformer isolation circuit 11. Moreover, the temperature detection module 122 in the present application can control the working state of the input module 111 based on the temperature information, without setting up additional control chips and detection circuits to process the temperature information, saving the manufacturing cost and avoiding the problem of information interference caused by a long detection circuit.

[0043] In order to ensure the accuracy of the temperature sampling by the temperature detection module 122, in one example, Figure 3As shown, the temperature detection module 122 may include a thermistor R1 and a voltage divider unit 1221, wherein one end of the thermistor R1 is connected to the output end of the transformer 112 and the input end of the plurality of output modules 113, and the thermistor R1 may sample the current temperature of the transformer 112, and adjust the resistance of the thermistor R1 according to the sampling information to adjust the magnitude of the output voltage of the thermistor R1. Here, it can be understood that the thermistor R1 may adjust the resistance according to the sampled temperature, that is, when the temperature rises, the resistance of the thermistor R1 decreases, and when the temperature decreases, the resistance of the thermistor R1 increases. Exemplarily, when the thermistor R1 samples that the current temperature of the transformer 112 is always the first temperature when it initially works, the resistance of the thermistor R1 remains unchanged, and the switch module 121 is turned off at this time; when the thermistor R1 samples that the current temperature rises to the second temperature after the transformer 112 has worked normally for a period of time, since the temperature rise of the transformer 112 is low at this time, the resistance of the thermistor R1 is still large, and the output voltage corresponding to the output of the thermistor R1 is small, and the switch module 121 is turned off at this time; when the thermistor R1 samples that the current temperature rises to the third temperature after the transformer 112 has worked for a period of time, the temperature of the transformer 112 is high at this time, so the resistance of the thermistor R1 decreases accordingly, and the output voltage corresponding to the output of the thermistor R1 is large, and the switch module 121 is turned on at this time.

[0044] One end of the voltage divider unit 1221 is connected to the other end of the thermistor R1 and the controlled end of the switch module 121, and the other end of the voltage divider unit 1221 is grounded. The voltage divider unit 1221 is used to divide the output voltage of the thermistor R1 to obtain a divided voltage, so that the switch module 121 receives a divided voltage corresponding to the output voltage of the thermistor R1.

[0045] Exemplarily, a certain temperature can be set as a preset temperature, and a voltage corresponding to the preset temperature can be set as the on-voltage of the switch module 121. When the current temperature sampled by thermistor R1 is less than or equal to the preset temperature, it indicates that the temperature of transformer 112 is normal, the voltage divided by voltage divider unit 1221 is less than the on-voltage of switch module 121, switch module 121 is turned off, and input module 111 is in working state. When the current temperature sampled by thermistor R1 is greater than the preset temperature, it indicates that the temperature of transformer 112 is abnormal, the voltage divided by voltage divider unit 1221 is greater than the on-voltage, and input module 111 stops working.

[0046] The thermistor R1 has a high sensitivity. The present application samples the current temperature of the transformer 112 through the thermistor R1 to ensure the reliability and accuracy of the sampling. At the same time, the voltage corresponding to the preset temperature is set as the turn-on voltage of the switch module. The output voltage of the voltage divider unit 1221 is divided by the voltage divider unit 1221 to obtain the divided voltage, so that the over-temperature protection circuit 12 can control the on and off of the switch module 121 based on the divided voltage to achieve control of the input module 111. There is no need to set up an additional control chip and detection circuit to process the temperature information, which saves manufacturing costs and avoids the problem of information interference caused by a long detection circuit.

[0047] Optional, such as Figure 4 As shown, the voltage dividing unit 1221 may include a voltage dividing resistor R2, or may be other devices or circuits with a voltage dividing function, and the present application does not impose any specific limitation on this.

[0048] Below, the over-temperature protection circuit 12 provided in the embodiment of the present application is exemplarily described by taking the voltage dividing unit 1221 as the voltage dividing resistor R2.

[0049] In one example, if Figure 5 As shown, the over-temperature protection circuit 12 may further include a rectifier module 123, one end of the rectifier module 123 is connected to the other end of the thermistor R1, and the other end of the rectifier module 123 is connected to one end of the voltage divider resistor R2 (i.e., the voltage divider unit 1221), for rectifying the output voltage output by the thermistor R1, and outputting the rectified output voltage to the voltage divider resistor R2, so as to ensure the stability of the output voltage output to the voltage divider resistor R2.

[0050] Optional, such as Figure 6 As shown, the rectifier module 123 can be a first diode D1, one end of the first diode D1 is connected to the other end of the thermistor R1, and the other end of the rectifier module 123 is connected to one end of the voltage divider resistor R2, and is used to rectify the output voltage output by the thermistor R1 to ensure the stability of the output voltage output to the voltage divider resistor R2.

[0051] In one example, if Figure 7 As shown, the over-temperature protection circuit 12 may further include a filtering unit 124, one end of the filtering unit 124 is connected to the other end of the thermistor R1 and the controlled end of the switch module 121, and the other end of the filtering unit 124 is grounded. The filtering unit 124 is used to filter the divided voltage, that is, to eliminate the AC component in the divided voltage and reduce the ripple coefficient of the divided voltage.

[0052] Optionally, the filtering unit 124 may be a filtering capacitor, or other device or circuit with filtering function, and this application does not impose any specific limitation on this.

[0053] In the embodiment of the present application, the temperature of the transformer 112 can be sampled in real time by the temperature detection module 122, and different output voltages can be outputted by the temperature detection module 122 according to different detected temperatures, and the output voltage is rectified and divided to obtain the divided voltage, and then the divided voltage is filtered to control the on and off of the switch module 121 by the divided voltage after filtering, so as to realize the control of the working state of the input module 111. In this way, the working state of the input module 111 is controlled by the temperature information sampled in real time by the temperature detection module 122, so as to avoid the problem that the transformer 112 cannot be used normally due to the high temperature, and ensure the reliability of the transformer isolation circuit 11. Moreover, the temperature detection module 122 in the present application can control the working state of the input module 111 based on the temperature information, without setting up an additional control chip and a detection circuit to process the temperature information, saving the manufacturing cost and avoiding the problem of information interference caused by a long detection circuit.

[0054] Optional, such as Figure 8 As shown, the switch module 121 can be an N-type metal-oxide-semiconductor (NMOS), the source of the NMOS is grounded, the drain of the NMOS is connected to the second end of the input module 111, and the gate of the NMOS is connected to the output end of the temperature detection module. Here, it is worth noting that the switch module 121 can also be other devices (such as relays) or circuits with switch functions, and this application does not make specific restrictions on this.

[0055] Below, the power supply circuit 1 provided in the embodiment of the present application is exemplarily described by only taking the switch module 121 as NMOS.

[0056] In one example, if Fig. 9 As shown, the transformer isolation circuit 11 provided in the embodiment of the present application may also include a control module 114, a first end of the control module 114 is connected to the drain of the NMOS (the second end of the switch module 121), a second end of the control module 114 is connected to the second end of the input module 111, and a third end of the control module 114 is grounded. The control module 114 can control the working state of the input module 111 according to the on-off correspondence of the NMOS.

[0057] For example, Fig.10As shown, the control module 114 may include an optical coupler OC and a voltage regulator diode D2. The first end of the optical coupler OC is connected to the power supply voltage, the second end of the optical coupler OC is respectively connected to the drain of the NMOS and one end of the voltage regulator diode D2, the third end and the fourth end of the optical coupler OC are respectively connected to the second end of the input module 111, and the other end of the voltage regulator diode D2 is grounded. The voltage regulator diode D2 is used to provide a reference voltage. When the divided voltage output by the voltage divider unit 1221 is greater than the conduction voltage of the NMOS, the NMOS is turned on, and the reference voltage of the voltage regulator diode D2 decreases. The control module 114 can control the input module 111 to stop working, so that the transformer 112 no longer works, thereby achieving heat dissipation of the transformer 112. When the divided voltage output by the voltage divider unit 1221 is less than the conduction voltage of the NMOS, the NMOS is turned off, the reference voltage of the voltage regulator diode D2 remains unchanged, and the control module 114 controls the input module 111 to continue working. In this way, the over-temperature protection circuit 12 provided in the embodiment of the present application realizes the control of the input module 111 by the control module 114 by controlling the on and off of NMOS. There is no need to set up additional control chips and detection circuits to process temperature information, which saves manufacturing costs and avoids the problem of information interference caused by a long detection circuit.

[0058] An embodiment of the present application also provides an integrated circuit board, including a circuit board body and the power supply circuit 1 in the above embodiment, and the power supply circuit 1 is arranged on the circuit board body. Here, it is worth noting that other circuits can also be integrated on the integrated circuit board provided in the embodiment of the present application, and the present application does not make any specific restrictions on this.

[0059] like Fig.11 As shown, the embodiment of the present application further provides a display device, which includes a display panel 2 and the power circuit 1 in the above embodiment, and the display panel 2 may include a backlight circuit 21 and a display system 22, wherein the multiple output modules 113 in the power circuit 1 can be respectively used to connect with the backlight circuit 21 and the display system 22, so that the power circuit 1 provides stable voltages for the backlight circuit 21 and the display system 22. The beneficial effects that can be achieved by the display device include the beneficial effects that can be achieved by the above power circuit 1, which will not be described in detail.

[0060] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0061] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0062] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0063] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0064] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A power supply circuit, characterized in that: include: A transformer isolation circuit comprises an input module, a transformer and a plurality of output modules, wherein a first end of the input module is connected to a primary winding of the transformer, and a plurality of secondary windings of the transformer are connected to a plurality of the output modules in a one-to-one correspondence; as well as, An over-temperature protection circuit comprises a switch module and a temperature detection module, wherein a first end of the switch module is grounded, and a second end of the switch module is connected to a second end of the input module; an input end of the temperature detection module is connected to a plurality of secondary windings of the transformer, and is used to sample the current temperature of the transformer, and adjust the output voltage of the temperature detection module according to the sampling information, and an output end is connected to a controlled end of the switch module, so as to control the on and off of the switch module according to different output voltages of the temperature detection module; If the switch module is turned on, the input module stops working; if the switch module is turned off, the input module starts working.

2. The power supply circuit according to claim 1, characterized in that: The temperature detection module comprises: a thermistor, one end of which is connected to the output end of the transformer and the input ends of the plurality of output modules, for sampling the current temperature of the transformer and adjusting the resistance of the thermistor according to the sampling information to adjust the output voltage of the thermistor; and A voltage dividing unit, one end of which is connected to the other end of the thermistor and the controlled end of the switch module, and is used for dividing the output voltage of the thermistor to obtain a divided voltage, and the other end of which is grounded; When the current temperature sampled by the thermistor is less than or equal to the preset temperature, the divided voltage after the voltage divider unit is divided is less than the on-voltage of the switch module, the switch module is turned off, and the input module starts working; when the current temperature sampled by the thermistor is greater than the preset temperature, the divided voltage after the voltage divider unit is divided is greater than the on-voltage, and the input module stops working.

3. The power supply circuit according to claim 2, characterized in that: The over-temperature protection circuit also includes: A rectifier module has one end connected to the other end of the thermistor and the other end connected to one end of the voltage divider unit, and is used to rectify the output voltage of the thermistor.

4. The power supply circuit according to claim 3, characterized in that: The rectifier module comprises: A first diode has one end connected to the other end of the thermistor and the other end connected to one end of the voltage divider unit, and is used to rectify the output voltage of the thermistor.

5. The power supply circuit according to claim 2, characterized in that: The over-temperature protection circuit also includes: A filtering unit has one end connected to the other end of the thermistor and the controlled end of the switch module and the other end grounded, and is used for filtering the divided voltage.

6. The power supply circuit according to claim 1, characterized in that: The switch module comprises: NMOS, the source is grounded, the drain is connected to the second end of the input module, and the gate is connected to the output end of the temperature detection module.

7. The power supply circuit according to any one of claims 1 to 6, characterized in that: The power supply circuit also includes: The control module has a first end connected to the second end of the switch module, a second end connected to the second end of the input module, and a third end connected to the ground, and is used to control the working state of the input module according to the on-off state of the switch module.

8. The power supply circuit according to claim 7, characterized in that: The control module includes an optical coupler and a voltage stabilizing diode; The first end of the optical coupler is connected to the power supply voltage, the second end of the optical coupler is respectively connected to the second end of the switch module and one end of the voltage regulator diode, the third end and the fourth end of the optical coupler are respectively connected to the second end of the input module, the other end of the voltage regulator diode is grounded, and the voltage regulator diode is used to provide a reference voltage; When the switch module is turned on, the reference voltage of the voltage regulator diode drops, and the control module controls the input module to stop working; When the switch module is turned off, the reference voltage of the voltage regulator diode remains unchanged, and the control module controls the input module to start working.

9. An integrated circuit board, characterized in that: It comprises a circuit board body and a power supply circuit as claimed in any one of claims 1 to 8, wherein the power supply circuit is arranged on the circuit board body.

10. A display device, characterized in that: It comprises a display panel and a power supply circuit as described in any one of claims 1 to 8, wherein the display panel comprises a backlight circuit and a display system, and the plurality of output modules are respectively used to connect to the backlight circuit and the display system.

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