CN114387931A - Device for improving reliability of panel driving equipment - Google Patents
Device for improving reliability of panel driving equipment Download PDFInfo
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- CN114387931A CN114387931A CN202210032541.7A CN202210032541A CN114387931A CN 114387931 A CN114387931 A CN 114387931A CN 202210032541 A CN202210032541 A CN 202210032541A CN 114387931 A CN114387931 A CN 114387931A
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- 239000004973 liquid crystal related substance Substances 0.000 claims abstract description 92
- 239000003990 capacitor Substances 0.000 claims abstract description 54
- 230000000087 stabilizing effect Effects 0.000 claims abstract description 33
- 238000005070 sampling Methods 0.000 claims abstract description 16
- 230000005669 field effect Effects 0.000 claims description 13
- 230000000694 effects Effects 0.000 claims description 8
- 230000006641 stabilisation Effects 0.000 claims description 8
- 238000011105 stabilization Methods 0.000 claims description 8
- 230000002411 adverse Effects 0.000 claims description 6
- 238000002955 isolation Methods 0.000 claims description 4
- 230000009286 beneficial effect Effects 0.000 abstract 1
- 239000000758 substrate Substances 0.000 description 5
- 238000000034 method Methods 0.000 description 3
- 230000003139 buffering effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/087—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for dc applications
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- Theoretical Computer Science (AREA)
- Liquid Crystal Display Device Control (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
The invention provides a device for improving the reliability of panel driving equipment, which mainly comprises the following modules: the liquid crystal display device comprises an input power supply module for providing working voltage, a control signal module for outputting a control signal to control the working state of the liquid crystal display device, a voltage selection module for selecting rated working voltage for the liquid crystal load, a voltage stabilizing module, an overcurrent protection module and the liquid crystal load. The voltage stabilizing module receives the high/low level control signal output by the control signal module, and can control the input working voltage to charge the delay capacitor preferentially at the power-on moment so as to provide a certain power-on delay buffer time for the liquid crystal load and prevent the liquid crystal load from being burnt out due to the increase of the instantaneous voltage; and the overcurrent protection module detects the working current of the liquid crystal load by using the sampling resistor and the operational amplifier, rapidly pulls the control signal down to GND when the current is overlarge, and rapidly closes the whole working device. The invention has the beneficial effects that: the liquid crystal display screen is effectively protected, the equipment is stable to work, the structure is simple, and the cost is low.
Description
Technical Field
The invention relates to the technical field of liquid crystal display, in particular to a device for improving the reliability of panel driving equipment.
Background
With the development of science and technology, Liquid Crystal Display devices (LCDs) are widely used in many fields, have the advantages of thin body, low power consumption, low voltage driving and the like, are widely used in Liquid Crystal televisions, tablet computers, smart phones, notebook computers, digital cameras and various projection devices, and dominate the field of flat panel Display.
The Liquid Crystal panel is mainly composed of a Thin Film Transistor Array Substrate (TFT Array Substrate), a Color Filter Substrate (CF), and a Liquid Crystal Layer (Liquid Crystal Layer) disposed between the two substrates, and the Liquid Crystal panel has an operation principle that a driving circuit provides a driving voltage and applies the driving voltage to the two substrates to control the rotation of Liquid Crystal molecules of the Liquid Crystal Layer, so as to refract light of the backlight module to generate a picture.
Due to the defects of the manufacturing process, the liquid crystal display device may have the phenomena of unstable voltage and overlarge impulse current at the moment of electrifying and in the using process, and the liquid crystal display device is easy to burn due to overlarge heat productivity caused by overlarge driving current. In order to control the stability of the liquid crystal display device, protective devices such as voltage stabilization and overcurrent need to be introduced into the liquid crystal display device, but the devices are very complex and high in cost. When the driving current is too high, the device outputs a control signal to start a related protection circuit, so that the liquid crystal display device is prevented from being damaged, the normal operation of the liquid crystal display device is ensured, and the stability and the adaptability of the system are further improved.
Disclosure of Invention
The embodiment of the invention aims to provide a simple and reliable device for controlling the stable work of the liquid crystal display equipment, solve the existing design defects, realize voltage stabilization and overcurrent protection of the liquid crystal display equipment at the power-on moment and in the working process, avoid the damage of the liquid crystal display equipment due to unstable voltage and overlarge impact current, and improve the system stability.
The device related by the invention mainly comprises the following modules: the device comprises an input power supply module, a control signal module, a voltage selection module, a voltage stabilizing module, an overcurrent protection module and a liquid crystal load. The input power supply module provides working voltage for the control signal module and the voltage selection module; the voltage selection module is a module capable of generating different selection voltages and is used for receiving the electric energy input into the power supply module and selecting a matched rated working voltage for the liquid crystal load; the control signal module outputs a high/low level control signal to the voltage stabilizing module to control the working state of the liquid crystal display equipment; the input end of the voltage stabilizing module receives a high/low level control signal from the control module, and through the delay capacitor, the phase inverter, the MOS tube switch, the filter capacitor and other devices, the input working voltage can be controlled to charge the delay capacitor preferentially at the electrifying moment, a certain electrifying delay buffer time is provided for the liquid crystal load, the working voltage is stabilized, the liquid crystal load is prevented from being burnt out due to the increase of the instantaneous voltage, and meanwhile, current clutter generated in a circuit is filtered, and the liquid crystal load is prevented from generating bad phenomena such as screen splash, screen flicker and the like; the overcurrent protection module receives the output voltage of the voltage stabilizing module, utilizes the sampling resistor and the operational amplifier to detect the working current of the liquid crystal load, compares the working current with a threshold voltage through the comparator, rapidly pulls down the control signal to GND when the current is overlarge, closes the working device, protects the liquid crystal load from being burnt, and ensures that the liquid crystal display equipment is stable, simple and reliable.
The voltage stabilizing module comprises a first resistor, a first capacitor, an external power supply VCC, a second resistor, a first triode, a third resistor, a second field effect transistor, a second capacitor, a fourth resistor and a third capacitor. One end of the first resistor is electrically connected with the output end of the control signal module and the output end of the overcurrent protection module and used for receiving a high/low level control signal from the control signal module, the other end of the first resistor is electrically connected with one end of the first capacitor and the base electrode of the first triode, the other end of the first capacitor is grounded, and the first delay capacitor is charged preferentially when being powered on, so that certain delay buffer time is provided. The first triode is an NPN type triode, an emitting electrode of the first triode is grounded, a collecting electrode of the first triode is electrically connected with one end of the second resistor and one end of the third resistor, the first triode performs an anti-phase effect on the high/low level control signal received by the base electrode, and the collecting electrode of the first triode outputs a low/high level control signal. The other end electric connection external power VCC of second resistance, the other end electric connection second field effect transistor's grid of third resistance. The drain electrode of the second field effect transistor is electrically connected with the output voltage of the voltage selection module, the source electrode of the second field effect transistor is electrically connected with one end of a fifth resistor of the second capacitor, the fourth resistor, the third capacitor and the overcurrent protection module, and the other end of the second capacitor, the fourth resistor and the third capacitor is grounded. The second field effect transistor receives the low/high level control signal of the collector of the first triode, when the second triode normally works, the source electrode is conducted with the drain electrode, the rated working voltage output by the voltage selection module is output to the overcurrent protection module through the P-channel depletion type second field effect transistor, and is output to the liquid crystal load 150 through the fifth resistor. The second capacitor is a filter capacitor, the fourth resistor is a current-limiting resistor, current clutter in a circuit can be effectively filtered, and adverse phenomena such as screen splash and screen flicker of a liquid crystal load are avoided. The third capacitor is a voltage stabilizing capacitor, and when the liquid crystal display is powered on, the voltage selecting module outputs electric energy to the overcurrent protection module and the liquid crystal load, and the liquid crystal load is protected from working stably under the voltage stabilizing effect of the third capacitor.
The overcurrent protection module comprises a fifth resistor, an operational amplifier, a comparator, a sixth resistor, a third triode, a first diode and a seventh resistor. The fifth resistor is a resistor (0-10R) with a small resistance value, plays a role in limiting current during normal work and serves as a sampling feedback resistor when the current is too large. One end of the fifth resistor is electrically connected with the output end of the voltage stabilizing module and the non-inverting input end of the operational amplifier, and the other end of the fifth resistor is electrically connected with the inverting input end of the operational amplifier and the voltage input end of the liquid crystal load. Under an overcurrent state, the resistance value of the fifth resistor is small, and the voltage drop between the two ends of the fifth resistor is small, so that the fifth resistor needs to be amplified by the operational amplifier and then compared with a threshold voltage. The input end of the operational amplifier receives and amplifies the voltage at two ends of the fifth resistor of the sampling resistor, the output end of the operational amplifier is electrically connected with one end of the comparator, the comparator is compared with a threshold voltage, and the output end of the comparator outputs a comparison result. One end of the sixth resistor is electrically connected with the output end of the comparator, and the other end of the sixth resistor is electrically connected with the base electrode of the third NPN type triode. And the emitter of the third NPN type triode is grounded, and the collector of the third NPN type triode is electrically connected with the cathode of the first diode. The positive electrode of the first diode is electrically connected with one end of a seventh resistor, the other end of the seventh resistor is electrically connected with a control signal module, and the output end of the control signal module is connected with the input end of the voltage stabilizing module. When the circuit normally works, the sampling voltage at the two ends of the fifth resistor passes through the amplifier, then the output voltage is less than or equal to the threshold voltage, the comparator outputs a low level signal according to the comparison result, the third triode is turned off at a low level, the first diode is cut off, the voltage stabilizing module is not affected, and all modules of the circuit normally work; when the current of the liquid crystal display device is overlarge, the sampling voltage at two ends of the fifth resistor passes through the amplifier and then the output voltage is larger than the threshold voltage, the comparator outputs a high level signal according to the comparison result, the high level of the third triode is conducted, the negative electrode of the first triode is the low level, the positive electrode of the first triode is the high level and is in a conducting state, the input voltage of the voltage stabilizing module (namely the control signal of the control signal module) is rapidly reduced to GND, the low level of the first triode is cut off, the high level of the grid of the second field effect tube is cut off, the voltage selecting module stops providing rated working voltage for the overcurrent protection module and the liquid crystal load, and meanwhile, the third capacitor discharges electricity to the liquid crystal load, so that the liquid crystal load is prevented from being burnt due to sudden increase of the current. Particularly, the second field effect transistor is turned off in an overcurrent state, so that an isolation effect is achieved, the phenomenon that an overlarge current recoils to the voltage selection module and the voltage stabilization module circuit from the source electrode to cause adverse effects is prevented, and the stability of the circuit is effectively guaranteed.
Compared with the prior art, the invention adopting the technical scheme has the following technical effects:
1. according to the invention, the liquid crystal load power-on delay buffering is realized through the voltage stabilizing module, the phenomenon of screen flashing caused by overlarge voltage at the moment of power-on of the liquid crystal load is avoided, meanwhile, clutter in the circuit is effectively filtered, and the stability of circuit signals is effectively ensured.
2. The invention realizes that the control signal is quickly closed when the current is overlarge by judging whether the liquid crystal load works normally, so that the liquid crystal display equipment stops working, the liquid crystal display equipment is protected from being burnt, and the working safety of the circuit is ensured.
3. The invention can realize the isolation from the front-end working circuit in an overcurrent state and prevent the adverse effect of overlarge current on the front-end circuit.
4. The invention has simple circuit design, can effectively realize the stable work of the liquid crystal display equipment, is economic and convenient, and improves the reliability of the liquid crystal display equipment.
Drawings
FIG. 1 is a schematic diagram of a circuit module frame according to an embodiment of the invention;
fig. 2 is a functional circuit diagram of a device for controlling stable operation of a liquid crystal display device according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
As shown in fig. 1, an embodiment of the present invention provides an apparatus for improving reliability of a panel driving device, including: the input power supply module 110, the control signal module 120, the voltage selection module 160, the voltage stabilization module 130, the overcurrent protection module 140, and the liquid crystal load 150. The input power supply module 110 provides an operating voltage for the control signal module 120 and the voltage selection module 160; the voltage selection module 160 can generate different selection voltages through a power supply conversion mode, is used for receiving electric energy input into the power supply module, and converts the electric energy into specific voltage according to load requirements, so that matched rated working voltage is selected for the liquid crystal load; a control signal module 120 for outputting a high/low level control signal to the voltage stabilizing module 130 to control the operating state of the liquid crystal display device; the input end of the voltage stabilizing module 130 receives a high/low level control signal from the control module, and through a delay capacitor, a phase inverter, an MOS tube switch, a filter capacitor and other devices, the input working voltage can be controlled to charge the delay capacitor preferentially at the power-on moment, so that a certain power-on delay buffer time is provided for the liquid crystal load, the working voltage is stabilized, the liquid crystal load is prevented from being burnt out due to the increase of the instantaneous voltage, and meanwhile, current clutter generated in a circuit is filtered, and the adverse phenomena of screen splash, screen flicker and the like of the liquid crystal load are avoided; the overcurrent protection module 140 receives the output voltage of the voltage stabilization module, detects the working current of the liquid crystal load by using the sampling resistor and the operational amplifier, compares the working current with a threshold voltage through the comparator, rapidly pulls down the control signal to GND when the current is too large, closes the working device, and protects the liquid crystal load from being burnt.
The following describes in detail an apparatus for controlling stable operation of a liquid crystal display device according to the present invention with reference to specific embodiments and accompanying drawings. As shown in fig. 2, the voltage stabilizing module 130 includes a first resistor R1, a first capacitor C1, an external power VCC, a second resistor R2, an NPN-type first transistor Q1, a third resistor R3, a P-channel depletion type second fet Q2, a second capacitor C2, a fourth resistor R4, and a third capacitor C3. One end of the first resistor R1, i.e., the a0 node, is electrically connected to the output terminal of the control signal module 120 and the positive electrode of the first diode D1 of the over-current protection module 140, and receives the high/low level control signal from the control signal module 110, the other end is electrically connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is grounded. A common terminal (e.g., a node B0 shown in fig. 2) of the first resistor R1 and the first capacitor C1 is electrically connected to a base of an NPN-type first transistor Q1, the first delay capacitor C1 is preferentially charged during power-on to provide a certain delay buffering time, an emitter of the first transistor Q1 is grounded, a collector of the first transistor Q1 is electrically connected to one end of the second resistor R2 and the third resistor R3 through a node C0, the first transistor Q1 performs an anti-phase action on a high/low level control signal received by the base, and the collector outputs a low/high level control signal. The other end of the second resistor R2 is electrically connected with an external power supply VCC, and the other end of the third resistor R3 is electrically connected with the grid electrode of a P-channel depletion type MOS transistor Q2. The drain of the P-channel depletion type MOS transistor Q2 is electrically connected to the output terminal of the voltage selection module 160, the source of the Q2 is electrically connected to the second capacitor C2, the fourth resistor R4, the third capacitor C3, and the fifth resistor R5 of the overcurrent protection module 140 through the D0 node, and the other ends of the second capacitor C2, the fourth resistor R4, and the third capacitor C3 are grounded. The P-channel depletion type MOS transistor Q2 receives the low/high level control signal output by the collector of the first triode Q1, the source and the drain of the P-channel depletion type MOS transistor Q2 are connected, and the rated working voltage output by the voltage selection module 160 is output to the overcurrent protection module 140 through the MOS transistor Q2 and is output to the liquid crystal load 150 through the fifth resistor R5. Second electric capacity C2 is filter capacitor, and fourth resistance R4 is the current-limiting resistor, can effectively filter the electric current clutter in the circuit, avoids liquid crystal load bad phenomena such as flower screen, splash screen to appear. The third capacitor C3 is a voltage stabilizing capacitor, and when the power is turned on, the voltage selection module 160 outputs electric energy to the overcurrent protection module 140 and the liquid crystal load 150, and the liquid crystal load is protected from stable operation by the voltage stabilizing effect of the third capacitor C3.
The over-current protection module 140 includes a fifth resistor R5, an operational amplifier a1, a comparator a2, a sixth resistor R6, a third triode Q3, a first diode D1, and a seventh resistor R7. The fifth resistor R5 is a resistor with a small resistance value, and plays a role in limiting current during normal operation, and is used as a sampling feedback resistor when the current is too large. One end of the fifth resistor R5 is electrically connected to the output terminal of the voltage regulator module and the non-inverting input terminal of the operational amplifier a1 through a node D0, and the other end is electrically connected to the inverting input terminal of the operational amplifier a1 and the input terminal of the liquid crystal load 150 through a node E0. The input end of the operational amplifier A1 receives and amplifies the voltage at the two ends of the sampling resistor R5, and the output end of the operational amplifier A1 is electrically connected with the input end of the comparator A2 through an F0 node. The comparator A2 converts the output voltage U of the F0 nodeF0And a threshold voltage VrefIn comparison, the output end of the comparator A2 outputs the comparison result. Because the resistance of the fifth resistor R5 is small, in an embodiment of the invention, the value of the fifth resistor R5 is about 0.1-0.5 ohm, which plays a role of current limiting during normal operation, and if the value is too large, the output will be causedThe current output to the liquid crystal load 150 is too small, which affects the operation of the liquid crystal display device; in an overcurrent state, the sampling feedback resistor has a small voltage drop between its two ends, so that it needs to be amplified by a certain factor through the operational amplifier A1 and then has a fixed threshold voltage VrefA comparison is made. The operational amplifier A1 has an amplification factor of 20 times, a normal operating current of 500mA, and an overcurrent state when the load current exceeds 700mA, so that the reference voltage VrefThe maximum working current is 700mA, the voltage across the sampling resistor R5 is about 0.35V, the voltage input to the positive terminal of the comparator through the operational amplifier A1 is about 7V, and the voltage is taken as the threshold voltage V of the negative input terminal of the comparatorref. One end of the sixth resistor R6 is electrically connected to the output end of the comparator a2, and the other end is electrically connected to the base of the third NPN transistor Q3. An emitter of the third NPN type triode Q3 is grounded, a collector is electrically connected to a cathode of the first diode D1, an anode of the first diode D1 is electrically connected to one end of a seventh resistor R7, and the other end of the seventh resistor R7 is electrically connected to the control signal module 120. When the liquid crystal display device normally works, the sampling voltage U at the two ends of the fifth resistor R5D0E0The output voltage is less than or equal to the threshold voltage V after passing through the amplifier A1refThe comparator A2 outputs a low level signal according to the comparison result, the third triode Q3 is turned off at low level, the first diode D1 is cut off, the voltage stabilizing module 130 is not affected, and all the modules of the circuit work normally; when the current of the liquid crystal display device is overlarge, the sampling voltage at the two ends of the fifth resistor R5 passes through the amplifier A1, and then the output voltage is larger than the threshold voltage VrefThe comparator a2 outputs a high level signal according to the comparison result, the third triode Q3 is turned on at a high level, the negative electrode of the first diode D1 is grounded, the positive electrode is at a high level and is in a conducting state, the input voltage of the voltage stabilizing module 130 is rapidly pulled down to GND, the first triode Q3 is turned off at a low level, the gate of the P-channel depletion type MOS transistor Q2 is turned off at a high level, the voltage selecting module 160 stops providing the rated working voltage for the overcurrent protection module 140 and the liquid crystal load 150, and meanwhile, the third capacitor C3 discharges the liquid crystal load to play a role in fast turn-off, thereby preventing the liquid crystal load from being burnt due to sudden increase of current. In particular, the P-channel depletion MOSThe tube Q2 is turned off in an overcurrent state, thereby playing an isolation role, preventing an excessive current from backflushing to the voltage selection module 160 and the voltage stabilization module 130 from the source electrode, causing adverse effects, and effectively ensuring the stability of the circuit.
The foregoing is directed to embodiments of the present invention and, more particularly, to a method and apparatus for controlling a power converter in a power converter, including a power converter, a display and a display panel.
Claims (9)
1. An apparatus for improving reliability of a panel driving device, the apparatus comprising: the input power supply module, the control signal module, the voltage selection module, the voltage stabilization module, the overcurrent protection module and the liquid crystal load are connected;
the input power supply module is connected with the control signal module and the voltage selection module to provide working voltage for the input power supply module;
the voltage selection module is connected with the input power supply module on one hand for receiving electric energy, and is connected with the voltage stabilization module on the other hand for selecting matched rated working voltage for the liquid crystal load;
the control signal module is connected with the voltage stabilizing module and outputs a high/low level control signal to the voltage stabilizing module to control the working state of the liquid crystal display equipment;
the input end of the voltage stabilizing module is connected with the control signal module to receive the high/low level control signal output by the control signal module, the input working voltage can be controlled to charge the delay capacitor preferentially at the power-on moment, a certain power-on delay buffer time is provided for the liquid crystal load, the working voltage is stabilized, the liquid crystal load is prevented from being burnt out due to the increase of the instantaneous voltage, and meanwhile, current clutter generated in a circuit is filtered, so that the bad phenomena of screen splash, screen flicker and the like of the liquid crystal load are avoided;
the overcurrent protection module is connected with the voltage stabilizing module to receive the output voltage of the voltage stabilizing module, the sampling resistor and the operational amplifier are used for detecting the working current of the liquid crystal load, the working current is compared with a threshold voltage through the comparator, the feedback output end of the overcurrent protection module is connected with the control signal module, the control signal is rapidly pulled down to GND when the current is overlarge, the working device is closed, and the liquid crystal load is protected from being burnt.
2. The apparatus as claimed in claim 1, wherein the voltage selection module receives power inputted to the power supply module and generates different selection voltages to be supplied to the liquid crystal load.
3. The apparatus according to claim 1, wherein the voltage stabilizing module comprises a first resistor, a first capacitor, an external power VCC, a second resistor, an NPN-type first transistor, a third resistor, a P-channel depletion type second fet, a second capacitor, a fourth resistor, and a third capacitor, wherein:
one end of the first resistor receives a high/low level control signal from the control signal module, the other end of the first resistor is electrically connected with the first capacitor and the base electrode of the first triode, and the first delay capacitor is charged preferentially when the first resistor is powered on, so that a certain delay buffer time is provided; the other end of the first capacitor is grounded;
the first triode is an NPN triode, a collector is electrically connected with a second resistor and a third resistor, the other end of the second resistor is electrically connected with an external power supply VCC, the other end of the third resistor is electrically connected with a grid electrode of a P-channel depletion type second field effect transistor, the first triode performs an anti-phase effect on a high/low level control signal received by a base electrode, and the collector outputs a low/high level control signal; the emitter of the first triode is grounded;
the drain electrode of the P-channel depletion type second field effect transistor is electrically connected with the output end of the voltage selection module and receives the working voltage selected by the voltage selection module, and the source electrode of the second field effect transistor is electrically connected with a second capacitor, a fourth resistor and a third capacitor which are connected in parallel and then grounded on one hand, and is electrically connected with a fifth resistor of the overcurrent protection module on the other hand; the second field effect transistor receives a low/high level control signal of the collector electrode of the first triode, the source electrode is conducted with the drain electrode, and the rated working voltage output by the voltage selection module is output to the overcurrent protection module through the second field effect transistor and is output to the liquid crystal load through the fifth resistor.
4. The device of claim 3, wherein the second capacitor is a filter capacitor, and the fourth resistor is a current limiting resistor, so as to effectively filter current noise in the circuit and avoid undesirable phenomena such as screen splash and screen flicker of the liquid crystal load.
5. The apparatus according to claim 3, wherein the third capacitor is a voltage stabilizing capacitor, and when the voltage selecting module is powered on, the voltage stabilizing function of the third capacitor protects the liquid crystal load from stable operation before the voltage selecting module outputs the electric energy to the over-current protection module and the liquid crystal load.
6. The apparatus of claim 1, wherein the over-current protection module comprises a fifth resistor, an operational amplifier, a comparator, a sixth resistor, an NPN-type third transistor, a first diode, and a seventh resistor, wherein:
the fifth resistor is a small-resistance resistor, plays a role in limiting current during normal work and serves as a sampling feedback resistor when the current is too large; one end of the fifth resistor is electrically connected with the output end of the voltage stabilizing module and the non-inverting input end of the operational amplifier, and the other end of the fifth resistor is electrically connected with the inverting input end of the operational amplifier and the voltage input end of the liquid crystal load; in an overcurrent state, the voltage is amplified by the operational amplifier and then is compared with a threshold voltage;
the input end of the operational amplifier receives and amplifies the voltage at the two ends of the fifth resistor, the output end of the operational amplifier is electrically connected with one end of the comparator, the comparator is compared with a threshold voltage, and the output end of the operational amplifier outputs a comparison result;
one end of the sixth resistor is electrically connected with the output end of the comparator, the other end of the sixth resistor is electrically connected with the base electrode of the NPN-type third triode, the emitting electrode of the third triode is grounded, the collecting electrode of the third triode is electrically connected with the negative electrode of the first diode, the positive electrode of the first diode is electrically connected with one end of the seventh resistor, and the other end of the seventh resistor is electrically connected with the control signal module.
7. The apparatus as claimed in claim 6, wherein the threshold voltage is a voltage value outputted by the operational amplifier when a certain proportion of the normal operating current is exceeded.
8. The apparatus of claim 6, wherein in the over-current protection module, when the circuit is operating normally, the sampled voltage across the fifth resistor passes through the amplifier and the output voltage is less than or equal to the threshold voltage, the comparator outputs a low-level signal, the third transistor is turned off at a low level, the first diode is turned off, the voltage stabilizing module is not affected, and the modules of the circuit operate normally; when the current of the liquid crystal display device is too large, the sampling voltage at the two ends of the fifth resistor passes through the amplifier and then the output voltage is larger than the threshold voltage, the comparator outputs a high level signal, the high level of the third triode is conducted, the first diode is conducted, the output voltage of the control signal module is rapidly pulled down to GND, the voltage selection module stops providing rated working voltage for the overcurrent protection module and the liquid crystal load, and meanwhile, the voltage stabilizing capacitor of the voltage stabilizing module discharges to the liquid crystal load to play a role in rapid turn-off, so that the liquid crystal load is prevented from being burnt due to sudden increase of the current.
9. The apparatus according to claim 3, wherein the voltage regulator module turns off the second fet in an overcurrent state to perform an isolation function, so as to prevent an excessive current from flowing back from the source to the voltage selection module and the voltage regulator module, thereby preventing adverse effects and effectively ensuring circuit stability.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210032541.7A CN114387931A (en) | 2022-01-12 | 2022-01-12 | Device for improving reliability of panel driving equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210032541.7A CN114387931A (en) | 2022-01-12 | 2022-01-12 | Device for improving reliability of panel driving equipment |
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| Publication Number | Publication Date |
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| CN114387931A true CN114387931A (en) | 2022-04-22 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210032541.7A Pending CN114387931A (en) | 2022-01-12 | 2022-01-12 | Device for improving reliability of panel driving equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114387931A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117220240A (en) * | 2023-10-12 | 2023-12-12 | 无锡奕帆微电子有限公司 | Hardware overcurrent protection circuit of handcart motor controller |
| WO2024045443A1 (en) * | 2022-08-29 | 2024-03-07 | 惠科股份有限公司 | Voltage regulating circuit and display panel |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105242426A (en) * | 2015-10-15 | 2016-01-13 | 合肥惠科金扬科技有限公司 | Power-up delay circuit of liquid crystal display and liquid crystal display |
| CN111883085A (en) * | 2020-09-28 | 2020-11-03 | 南京熊猫电子制造有限公司 | Device for improving stable work of liquid crystal equipment |
-
2022
- 2022-01-12 CN CN202210032541.7A patent/CN114387931A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105242426A (en) * | 2015-10-15 | 2016-01-13 | 合肥惠科金扬科技有限公司 | Power-up delay circuit of liquid crystal display and liquid crystal display |
| CN111883085A (en) * | 2020-09-28 | 2020-11-03 | 南京熊猫电子制造有限公司 | Device for improving stable work of liquid crystal equipment |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024045443A1 (en) * | 2022-08-29 | 2024-03-07 | 惠科股份有限公司 | Voltage regulating circuit and display panel |
| US12013710B2 (en) | 2022-08-29 | 2024-06-18 | HKC Corporation Limited | Voltage stabilizing circuit and display panel |
| CN117220240A (en) * | 2023-10-12 | 2023-12-12 | 无锡奕帆微电子有限公司 | Hardware overcurrent protection circuit of handcart motor controller |
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Application publication date: 20220422 |
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| RJ01 | Rejection of invention patent application after publication |