CN217521739U - Backlight drive board operating condition detection circuitry - Google Patents
Backlight drive board operating condition detection circuitry Download PDFInfo
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- CN217521739U CN217521739U CN202221502276.6U CN202221502276U CN217521739U CN 217521739 U CN217521739 U CN 217521739U CN 202221502276 U CN202221502276 U CN 202221502276U CN 217521739 U CN217521739 U CN 217521739U
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- backlight driving
- driving board
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- type triode
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
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Abstract
The utility model discloses a drive plate operating condition detection circuitry is shaded, include: the backlight driving circuit comprises a backlight driving board, a voltage stabilizing tube, a first divider resistor, a second divider resistor, a current limiting resistor and an NPN type triode, wherein the voltage output end of the backlight driving board is connected with the negative electrode of the voltage stabilizing tube, two ends of the first divider resistor are respectively connected with the positive electrode of the voltage stabilizing tube and the base electrode of the NPN type triode, one end of the second divider resistor is grounded, and the other end of the second divider resistor is connected with the base electrode of the NPN type triode; the emitting electrode of the NPN type triode is grounded, the collecting electrode of the NPN type triode is connected with VCC voltage through a current limiting resistor, and the collecting electrode of the NPN type triode is connected with one GPIO pin of the CPU. Because the output voltages of the backlight driving board during normal driving and abnormal driving are different, the circuit can give different voltage signals to the CPU, and therefore the CPU can know whether the backlight driving board works normally or not in real time.
Description
Technical Field
The utility model relates to a LCD display screen technical field especially relates to a drive plate operating condition detection circuitry in a poor light.
Background
In LCD display, LED backlight is usually used as the main light source, and the LEDs are connected in series and parallel as the backlight source of the LCD. In circuit design, the backlight is typically driven with a separate backlight driver board. The backlight driving board receives a DC power supply, enables and PWM dimming signals, and outputs high voltage to drive the LED backlight.
The conventional backlight driving board is not designed with a feedback signal, and when the LED backlight driving fails, the CPU cannot know it.
Accordingly, the prior art is deficient and needs improvement.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is: the working state detection circuit of the backlight driving board is provided, and a CPU (central processing unit) can conveniently know the working state of the backlight driving board in real time.
The technical scheme of the utility model as follows: provided is a backlight driving board operating state detection circuit, including: the backlight driving circuit comprises a backlight driving board, a voltage stabilizing tube, a first divider resistor, a second divider resistor, a current limiting resistor and an NPN type triode, wherein the voltage output end of the backlight driving board is connected with the negative electrode of the voltage stabilizing tube, two ends of the first divider resistor are respectively connected with the positive electrode of the voltage stabilizing tube and the base electrode of the NPN type triode, one end of the second divider resistor is grounded, and the other end of the second divider resistor is connected with the base electrode of the NPN type triode; the emitting electrode of the NPN type triode is grounded, the collecting electrode of the NPN type triode is connected with VCC voltage through a current limiting resistor, and the collecting electrode of the NPN type triode is connected with one GPIO pin of the CPU; and the reverse conducting voltage of the voltage-stabilizing tube is greater than the input voltage of the backlight driving board and less than the output voltage of the backlight driving board.
When the backlight driving board works normally, the voltage output end of the backlight driving board outputs normal LED backlight voltage; when the backlight driving board fails to be driven, for example: and in an overvoltage and overcurrent protection state, the backlight driving board is abnormally driven, and the LED backlight voltage is the same as the voltage input to the backlight driving board by the power supply.
When the backlight driving board normally drives and works, the voltage output by the backlight driving board is larger than the reverse conducting voltage of the voltage regulator tube, so that the voltage regulator tube can be conducted reversely, the voltage output by the backlight driving board is output to the first voltage dividing resistor and the second voltage dividing resistor, the base electrode of the NPN type triode is connected between the first voltage dividing resistor and the second voltage dividing resistor, the base electrode of the NPN type triode also obtains a voltage, the collector electrode and the emitter electrode of the NPN type triode are conducted, and the emitter electrode of the NPN type triode is grounded, so that the GPIO pin of the CPU of the collector electrode of the NPN type triode can be pulled down. When the driving of the backlight driving board fails, the voltage output by the voltage output end of the backlight driving board is the same as the voltage input by the power supply and is smaller than the reverse conduction voltage of the voltage regulator tube, and the voltage regulator tube cannot be conducted reversely, so that the collector and the emitter of the NPN type triode are not conducted, and the GPIO pin of the CPU of the collector of the NPN type triode are pulled high. The CPU acquires the height of the GPIO pin to know whether the backlight drive works normally in real time.
Further, the input voltage of the backlight driving board is 9-12V, and the output voltage of the backlight driving board is 20-70V; the reverse conducting voltage of the voltage stabilizing tube is 14-18V.
Further, the model of the stabilivolt is ZMM 15.
Further, the NPN type transistor is: MMBT 3904; the VCC voltage is 3.3V; the resistance value of the current limiting resistor is 10K.
Further, the resistance value of the first divider resistor is 51K, and the resistance value of the second divider resistor is 10K.
When the scheme is adopted, the utility model provides a drive plate operating condition detection circuitry is shaded, because the voltage of drive plate normal drive output is different with when unusual the drive in a poor light, the circuit through this scheme just can give the different voltage signal of CPU to can let CPU learn in real time whether normal work of drive plate in a poor light.
Drawings
Fig. 1 is a schematic circuit diagram of an embodiment of the present invention.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
Referring to fig. 1, the present embodiment provides a circuit for detecting a working state of a backlight driver board, including: the backlight driving circuit comprises a backlight driving board 10, a voltage regulator tube 11, a first divider resistor 13, a second divider resistor 14, a current limiting resistor 15 and an NPN type triode 16, wherein the voltage output end of the backlight driving board 10 is connected with the negative electrode of the voltage regulator tube 11, two ends of the first divider resistor 13 are respectively connected with the positive electrode of the voltage regulator tube 11 and the base electrode of the NPN type triode 16, one end of the second divider resistor 14 is grounded, and the other end of the second divider resistor 14 is connected with the base electrode of the NPN type triode 16; an emitting electrode of the NPN type triode 16 is grounded, a collector electrode of the NPN type triode 16 is connected with VCC voltage through a current limiting resistor 15, and the collector electrode of the NPN type triode 16 is connected with a GPIO pin of the CPU; the reverse conducting voltage of the voltage regulator tube 11 is greater than the input voltage of the backlight driving board 10 and less than the output voltage of the backlight driving board 10. In this embodiment, the surge tube 11 is of the type ZMM 15. The model of the NPN type triode 16 is: MMBT 3904. The VCC voltage is 3.3V; the resistance value of the current limiting resistor 15 is 10K. The resistance of the first divider resistor 13 is 51K, and the resistance of the second divider resistor 14 is 10K.
When the backlight driving board 10 works normally, the voltage output end of the backlight driving board 10 outputs normal LED backlight voltage; when the backlight driving board 10 fails to be driven, for example: the backlight driving board 10 is not normally driven in an overvoltage and overcurrent protection state, and the LED backlight voltage is the same as the voltage input by the power supply to the backlight driving board 10.
When the backlight driving board 10 is normally driven, the voltage output by the backlight driving board 10 is greater than the reverse conducting voltage of the voltage regulator tube 11, so that the voltage regulator tube 11 is conducted reversely, the voltage output by the backlight driving board 10 is output to the first voltage dividing resistor 13 and the second voltage dividing resistor 14, the base of the NPN type triode 16 is connected between the first voltage dividing resistor 13 and the second voltage dividing resistor 14, the base of the NPN type triode 16 also obtains a voltage, so that the collector and the emitter of the NPN type triode 16 are conducted, and the emitter of the NPN type triode 16 is grounded, so that the GPIO pin of the CPU of the collector of the NPN type triode 16 is pulled down. When the driving of the backlight driving board 10 fails, the voltage output by the voltage output end of the backlight driving board 10 is the same as the voltage input by the power supply and is smaller than the reverse conduction voltage of the voltage regulator tube 11, and the voltage regulator tube 11 cannot be conducted reversely, so that the collector and the emitter of the NPN type triode 16 are not conducted, and the GPIO pin of the CPU of the collector of the NPN type triode 16 is pulled high. The CPU acquires the height of the GPIO pin to know whether the backlight drive works normally in real time.
In this embodiment, the input voltage of the backlight driving board 10 is 12V, and the output voltage of the backlight driving board 10 is 20-70V; and the reverse conducting voltage of the voltage-regulator tube 11 is 15V.
To sum up, the utility model provides a drive plate operating condition detection circuitry is shaded, because the voltage of output is different when the drive plate is shaded normal drive and unusual drive, the circuit through this scheme just can give the different voltage signal of CPU to can let CPU learn in real time whether the drive plate is shaded normally to work.
The present invention is not limited to the above preferred embodiments, and any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.
Claims (5)
1. A backlight driving board working state detection circuit is characterized by comprising: the backlight driving circuit comprises a backlight driving board, a voltage stabilizing tube, a first divider resistor, a second divider resistor, a current limiting resistor and an NPN type triode, wherein the voltage output end of the backlight driving board is connected with the negative electrode of the voltage stabilizing tube, two ends of the first divider resistor are respectively connected with the positive electrode of the voltage stabilizing tube and the base electrode of the NPN type triode, one end of the second divider resistor is grounded, and the other end of the second divider resistor is connected with the base electrode of the NPN type triode; the emitting electrode of the NPN type triode is grounded, the collecting electrode of the NPN type triode is connected with VCC voltage through a current limiting resistor, and the collecting electrode of the NPN type triode is connected with one GPIO pin of the CPU; the reverse conducting voltage of the voltage stabilizing tube is larger than the input voltage of the backlight driving board and smaller than the output voltage of the backlight driving board.
2. The operation state detection circuit of a backlight driving board according to claim 1, wherein the input voltage of the backlight driving board is 9-12V, and the output voltage of the backlight driving board is 20-70V; the reverse conducting voltage of the voltage stabilizing tube is 14-18V.
3. The circuit for detecting the operating state of a backlight driving board according to claim 2, wherein the type of the voltage regulator tube is ZMM 15.
4. The circuit for detecting an operating state of a backlight driving board according to claim 1, wherein the NPN transistor has a type: MMBT 3904; the VCC voltage is 3.3V; the resistance value of the current limiting resistor is 10K.
5. A backlight driving board operation state detection circuit according to claim 1, wherein the first voltage-dividing resistor has a resistance of 51K, and the second voltage-dividing resistor has a resistance of 10K.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221502276.6U CN217521739U (en) | 2022-06-15 | 2022-06-15 | Backlight drive board operating condition detection circuitry |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221502276.6U CN217521739U (en) | 2022-06-15 | 2022-06-15 | Backlight drive board operating condition detection circuitry |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217521739U true CN217521739U (en) | 2022-09-30 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221502276.6U Active CN217521739U (en) | 2022-06-15 | 2022-06-15 | Backlight drive board operating condition detection circuitry |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217521739U (en) |
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2022
- 2022-06-15 CN CN202221502276.6U patent/CN217521739U/en active Active
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