CN202930901U - Power supply protection circuit for liquid crystal screen TCON plate - Google Patents
Power supply protection circuit for liquid crystal screen TCON plate Download PDFInfo
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- CN202930901U CN202930901U CN 201220580277 CN201220580277U CN202930901U CN 202930901 U CN202930901 U CN 202930901U CN 201220580277 CN201220580277 CN 201220580277 CN 201220580277 U CN201220580277 U CN 201220580277U CN 202930901 U CN202930901 U CN 202930901U
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Abstract
The utility model is suitable for power supply protection of a liquid crystal screen TCON plate, and provides a power supply protection circuit for a liquid crystal screen TCON plate, comprising a sampling detection circuit for sampling and detecting the output voltage of a movement plate, a switch circuit and a controller for controlling the switch circuit to switch on and off, wherein one end of the sampling detection circuit is connected with the voltage output end of the movement plate, the other end is connected with the input end of the controller, the output end of the controller is connected with the control end of the switch circuit, the input end of the switch circuit is connected with the voltage output end of the movement plate, and another end of the switch circuit is connected with the liquid crystal screen TCON plate. The power supply protection circuit can achieve the purpose of protecting a liquid crystal screen, and can protect a liquid crystal screen from being damaged when the power supply of the liquid crystal screen TCON plate does not accord with demands.
Description
Technical field
The utility model belongs to electronic technology field, relates in particular to a kind of power supply protection circuit of liquid crystal display screen TCON plate.
Background technology
At present the supply power voltage of liquid crystal display screen TCON plate (sequencing control plate) generally has three kinds of 3.3V, 5.0V and 12.0V.When the LCD product movement designs, liquid crystal display screen for the various supply power voltages of compatibility, can arrange three magnetic beads or 0 ohm of wire jumper as liquid crystal display screen supply power voltage option on machine core board, when joining different liquid crystal display screen, by selecting different magnetic beads or wire jumper to select the voltage that mates with the liquid crystal display screen supply power voltage, then through switching circuit of power supply, power delivery is arrived the TCON plate of liquid crystal display screen.
Although existing scheme can solve the compatibling problem of LCD product machine core board and liquid crystal display screen, if but the voltage of liquid crystal display screen is lower, and select magnetic bead or wire jumper to make a fault, the mistake gating magnetic bead or the wire jumper of high voltage, the TCON plate of liquid crystal display screen will be damaged, repair or scrap thereby cause screen to send, causing damage.
Therefore, need a kind of technical scheme, to address the above problem.
The utility model content
The purpose of this utility model is to provide a kind of power supply protection circuit of liquid crystal display screen TCON plate, is intended to solve the problem that liquid crystal display screen TCON plate is protected.
the utility model is to realize like this, a kind of power supply protection circuit of liquid crystal display screen TCON plate, described power supply protection circuit comprises the sample detecting circuit that the machine core board output voltage is carried out sample detecting, the controller of switching circuit and the described switching circuit conducting of control or shutoff, described sample detecting circuit one end connects the voltage output end of described machine core board, the other end connects described controller input, described controller output end connects the control end of described switching circuit, described switching circuit input connects the voltage output end of described machine core board, the other end connects described liquid crystal display screen TCON plate.
More specifically, described sample detecting circuit comprises the second resistance (R2) and the 3rd resistance (R3) to described machine core board output voltage dividing potential drop sampling.
More specifically, described sample detecting circuit also comprises the sampling filter electric capacity (C6) in parallel with described the 3rd resistance (R3).
More specifically, described sample detecting circuit also comprises the voltage stabilizing didoe (ZD1) in parallel with described the 3rd resistance (R3).
More specifically, described controller comprises MCU and control circuit.
6, power supply protection circuit according to claim 5, is characterized in that, described control circuit comprises triode (Q2), and the collector electrode of described triode (Q2) connects described switching circuit, grounded emitter, and base stage is connected to the output of described MCU.
More specifically, described switching circuit comprises MOS switching tube (Q1).
More specifically, described switching circuit also comprises soft the opening that be connected with described MOS switching tube (Q1)/soft shut-off circuit.
The utility model overcomes the deficiencies in the prior art; adopt power supply protection circuit to carry out sample detecting to the output voltage of machine core board; whether the output voltage that judges machine core board conforms to the supply power voltage of liquid crystal display screen TCON plate; if conform to the control switch circuit turn-on; otherwise the off state of maintained switch circuit; thereby reach the purpose of protection liquid crystal display screen, evade liquid crystal display screen TCON plate power supply undesirable and cause the generation of liquid crystal display screen damaged condition.
Description of drawings
Fig. 1 is the circuit theory diagrams of the utility model embodiment liquid crystal display screen TCON plate protective circuit;
Fig. 2 is the physical circuit figure of the utility model embodiment liquid crystal display screen TCON plate protective circuit.
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.
The liquid crystal display screen TCON plate protective circuit that the utility model embodiment provides comprises sample detecting circuit, controller and switching circuit as shown in Figure 1.Wherein: the magnetic bead on sample detecting circuit one end junctor central layer or the output of wire jumper S1, S2 and S3, the other end connects the input of controller, the control end of the output connecting valve circuit of controller; Magnetic bead on machine core board or wire jumper S1, S2 and S3 output be the input of connecting valve circuit also, and the output of switching circuit connects the TCON plate of liquid crystal display screen.
When joining screen, at first choose one in the magnetic bead on machine core board or wire jumper S1, S2 and S3, make the supply power voltage of the output voltage of machine core board and liquid crystal display screen adaptive, respectively 12V, 5V and 3.3V as magnetic bead or wire jumper S1, S2 and output voltage corresponding to S3, the supply power voltage of liquid crystal display screen is 5V, by magnetic bead or wire jumper S2 gating output voltage 5V.After the circuit gating, machine core board is to switching circuit output 5V voltage, magnetic bead on while sample detecting electric circuit inspection machine core board or the output of wire jumper S2, output voltage to machine core board carries out sample detecting, and the sample detecting result is transferred to controller, controller compares the sampled result of sample detecting circuit and the supply power voltage of liquid crystal display screen TCON plate, and according to conducting or the shutoff of comparative result control switch circuit.Specifically, the sample detecting electric circuit inspection to the output voltage of machine core board when satisfying the power supply voltage range of liquid crystal display screen TCON plate, controller control switch circuit turn-on; When the sample detecting electric circuit inspection to the output voltage of machine core board less than the supply power voltage lower limit of liquid crystal display screen TCON plate or on greater than the supply power voltage of liquid crystal display screen TCON plate in limited time; may be that magnetic bead or wire jumper are selected to make a fault; controller control switch circuit turn-offs; avoid to the voltage of liquid crystal display screen TCON plate output error, thereby protection liquid crystal display screen TCON plate is avoided damaging.
The physical circuit figure of the utility model embodiment as shown in Figure 2, comprise capacitor C 1 and capacitor C 2 to the filtering of machine core board output voltage, the sample detecting circuit comprises the second resistance R 2, the 3rd resistance R 3, voltage stabilizing didoe ZD1 and sampling filter capacitor C 6, the second resistance R 2 one end junctor central layer output voltage terminals, the other end is connected with in parallel the 3rd resistance R 3, voltage stabilizing didoe ZD1 and sampling filter capacitor C and is connected backward controller and exports sampled voltage (as shown in SAD in figure), the other end ground connection of the 3rd resistance R 3, voltage stabilizing didoe ZD1 and sampling filter capacitor C 6.Wherein the second resistance R 2 and 3 pairs of machine core board output voltages of the 3rd resistance R carry out dividing potential drop, and the voltage of voltage stabilizing didoe ZD1 subtend controller output carries out voltage stabilizing, and 6 pairs of sampled voltages of capacitor C carry out filtering.Controller comprises Micro-processor MCV (scheming not shown) and control circuit, control circuit comprises the 6th resistance R 6, the 7th resistance R 7 and triode Q2, the 7th resistance R 7 is connected across base stage and the emitter of triode Q2, the collector electrode connecting valve circuit of triode Q2, the base stage of the grounded emitter of triode Q2, triode Q2 is connected to the output (as shown in the VCC-PANEL-ON/OFF in Fig. 2) of MCU by the 6th resistance R 6, the input of MCU receives the sampled voltage of sample detecting circuit output.Switching circuit comprises MOS switching tube Q1, and soft the opening of switching tube that is made of the first resistance R 1, the 4th resistance R 4, the 5th resistance R 5 and diode D1, capacitor C 7/soft shut-off circuit.
After power on circuitry as shown in Figure 2, VCC is by magnetic bead or wire jumper S1, S2 or the selected supply power voltage of S3, correspond to 12V, 5V or 3.3V, and at this moment VCC-PANEL-ON/OFF is initialized as low level (if when MCU powers on, VCC-PANEL-ON/OFF is initialized as high level by MCU, needing to increase the one-level inverter circuit, to make VCC-PANEL-ON/OFF be low level, thereby when guaranteeing just to have powered on, MOS switching tube Q1 can conducting), triode Q2 is cut-off state, so not conducting of MOS switching tube Q1, VCC-PANEL is 0V, and liquid crystal display screen TCON plate is not powered.
After sampling by the second resistance R 2 and the 3rd resistance R 3 dividing potential drops, VCC delivers to the AD input port of MCU, signal is SAD, then read register value corresponding to SAD voltage by MCU, judge that whether the VCC voltage of SAD voltage corresponding to this register value before its sampling conform to the supply power voltage that liquid crystal display screen TCON plate requires, if conform to VCC-PANEL-ON/OFF is set to high level, triode Q2 saturation conduction, its current collection is low level very, MOS switching tube Q1 conducting is delivered to VCC-PANEL with VCC and is powered to liquid crystal display screen TCON plate; If do not conform to, VCC-PANEL-ON/OFF still keeps low level, and MOS switching tube Q1 continues to keep not conducting, thereby avoids the supply power voltage VCC of mistake is delivered to VCC-PANEL to the power supply of liquid crystal display screen TCON plate, reaches the purpose of protection liquid crystal display screen TCON plate.
Below just 8 AD mouths are illustrated take MCU AD mouth as 3.3V.
Owing to being 8 AD mouths of 3.3V, so the AD register value that 0V is corresponding is 0x00, the AD register value that 3.3V is corresponding is 0xFF.VCC has 12V, three kinds of situations of 5V and 3.3V, the SAD of maximum supply power voltage (being 12V) after the second resistance R 2 and the 3rd resistance R 3 dividing potential drops can not surpass 3.3V, because of SAD=VCC*R3/ (R2+R3), so 12V*R3/ (R2+R3)≤3.3V releases R3/R2≤33/87, so for example get the 3rd resistance R 3=3.3K, at this moment the second resistance R 2=10K can calculate different power voltage corresponding AD register value determination range such as following table:
| VCC(V) | R3(KΩ) | R2(KΩ) | SAD?(V) | SAD±10%(V) | AD register value determination range |
| 12.0 | 3.3 | 10 | 2.98 | 2.68～3.28 | 0xCF～0xFD |
| 5.0 | 3.3 | 10 | 1.24 | 1.12～1.36 | 0x56～0x69 |
| 3.3 | 3.3 | 10 | 0.82 | 0.74～0.90 | 0x39～0x46 |
Table one
In order to improve sampling precision, need to select sampling the second resistance R 2 and the 3rd resistance R 3 of ± 1% error, can suitably adjust in addition the determination range of SAD to adapt to the VCC voltage fluctuation.
As shown in Table 1, for example when joining the liquid crystal display screen of 5V, the scope of SAD ± 10% (V) is 1.12V～1.36V, corresponding AD register value scope is 0x56～0x69, if MCU reads register value corresponding to AD mouth voltage and drops in 0x56～0x69 scope, illustrate that the VCC supply power voltage conforms to the supply power voltage of liquid crystal display screen, VCC-PANEL-ON/OFF is set to high level, triode Q2 saturation conduction, its current collection is low level very, MOS switching tube Q1 conducting, thus VCC is delivered to VCC-PANEL to the power supply of liquid crystal display screen screen TCON plate; If MCU reads register value corresponding to AD mouth voltage not in 0x56～0x69 scope; illustrate that the VCC supply power voltage does not conform to the supply power voltage of liquid crystal display screen; VCC-PANEL-ON/OFF still keeps low level; MOS switching tube Q1 continues to keep not conducting; thereby avoid the supply power voltage VCC of mistake is delivered to VCC-PANEL to the power supply of screen TCON plate, reach the purpose of protection liquid crystal display screen TCON plate.Join the liquid crystal display screen of other supply power voltage by in like manner judging processing.
When Software for Design, join different liquid crystal display screens and can quote the different screen parameter code units of joining, in joining screen parameter code unit, AD register value determination range corresponding to liquid crystal display screen supply power voltage carried out predefine, can quote this predefine in the VCC-PANEL-ON/OFF control function, and the SAD register value that reads is judged, judge whether it drops in predefined AD register value determination range, thereby control the conducting of MOS switching tube Q1 and close.
In addition, when VCC and liquid crystal display screen supply power voltage were not inconsistent, MCU can control the LED LED flash and be pointed out.Voltage stabilizing didoe ZD1 is MCU AD mouth margin voltage protection diode; selecting the voltage stabilizing value of ZD1 is the margin voltage of MCU AD mouth; thereby can limit SAD voltage in the voltage stabilizing value of ZD1 or following, guarantee namely that also SAD voltage is no more than the margin voltage of MCU AD mouth, thereby protection MCU AD mouth.Sampled voltage filter capacitor C6 is used for burr and the noise of filtering SAD voltage, avoids software sampling to cause to the burr of fluctuation, noise voltage the action that opens by mistake logical MOS switching tube Q1.
The switching tube that is made of the first resistance R 1, the 4th resistance R 4, the 5th resistance R 5 and diode D1, capacitor C 7 is soft to be opened, soft shut-off circuit can be regulated rise time and the fall time of VCC-PANEL power supply, thereby satisfies the powering on of liquid crystal display screen TCON plate power reguirements, power-off sequential requirement.
When VCC-PANEL-ON/OFF is set to high level, triode Q2 saturation conduction, its current collection is low level very, at this moment capacitor C 7 is discharged by diode D1, the 4th resistance R 4 and triode Q2, the grid voltage of MOS switching tube Q1 descends gradually, when the grid voltage that discharges into MOS switching tube Q1 and source voltage pressure reduction reached its conduction threshold, MOS switching tube Q1 became conducting by closing, and can regulate the rise time of VCC-PANEL by adjusting resistance R4 and capacitor C 7.
When VCC-PANEL-ON/OFF is set to low level, triode Q2 cut-off, this moment is due to VCC ≈ VCC-PANEL, MOS switching tube Q1 source voltage and grid voltage pressure reduction are less than conduction threshold, so MOS switching tube Q1 cut-off, filter capacitor C4 and capacitor C 5 enter discharge condition, and VCC-PANEL descends gradually, and VCC charges by the first resistance R 1, the second resistance R 4,5 pairs of capacitor C 7 of the 5th resistance R simultaneously.when VCC-PANEL drops to enough low, when causing MOS switching tube Q1 source voltage and grid voltage pressure reduction to reach the critical conduction threshold value, MOS switching tube Q1 hangs down conducting, VCC process MOS switching tube Q1 is to capacitor C 4, capacitor C 5 chargings, VCC-PANEL rises, the grid voltage rising that VCC-PANEL rises and causes MOS switching tube Q1, the grid voltage of MOS switching tube Q1 raises and causes MOS switching tube Q1 source voltage and grid voltage pressure reduction to reduce, MOS switching tube Q1 source voltage and grid voltage pressure reduction reduce to cause MOS switching tube Q1 on-state rate to descend, MOS switching tube Q1 on-state rate descends and causes VCC-PANEL to descend, and the grid voltage rising that VCC charges and also causes MOS switching tube Q1 by the first resistance R 1, the 4th resistance R 4,5 pairs of capacitor C 7 of the 5th resistance R in like manner also causes VCC-PANEL to descend.Hence one can see that, and when VCC-PANEL finally dropped to 0V, VCC charged until the voltage on capacitor C 7 reaches the stable state that is about VCC by the first resistance R 1, the 4th resistance R 4,5 pairs of capacitor C of the 5th resistance R 7.Adjust the first resistance R 1, the 4th resistance R 4, the 5th resistance R 5 and capacitor C 7 and can regulate the fall time of VCC-PANEL, but affect simultaneously the rise time of VCC-PANEL owing to adjusting the 4th resistance R 4 and capacitor C 7, so after the rise time mixes up, can adjust by adjusting the first resistance R 1 fall time of VCC-PANEL, and the 5th resistance R 5 forms the charging path with capacitor C 7, generally is fixed on tens K Ω and gets final product.
The above is only preferred embodiment of the present utility model; not in order to limit the utility model; all any modifications of doing within spirit of the present utility model and principle, be equal to and replace and improvement etc., within all should being included in protection range of the present utility model.
Claims (8)
1. the power supply protection circuit of a liquid crystal display screen TCON plate, it is characterized in that, described power supply protection circuit comprises the sample detecting circuit that the machine core board output voltage is carried out sample detecting, the controller of switching circuit and the described switching circuit conducting of control or shutoff, described sample detecting circuit one end connects the voltage output end of described machine core board, the other end connects described controller input, described controller output end connects the control end of described switching circuit, described switching circuit input connects the voltage output end of described machine core board, the other end connects described liquid crystal display screen TCON plate.
2. power supply protection circuit according to claim 1, is characterized in that, described sample detecting circuit comprises the second resistance (R2) and the 3rd resistance (R3) to described machine core board output voltage dividing potential drop sampling.
3. power supply protection circuit according to claim 2, is characterized in that, described sample detecting circuit also comprises the sampling filter electric capacity (C6) in parallel with described the 3rd resistance (R3).
4. power supply protection circuit according to claim 2, is characterized in that, described sample detecting circuit also comprises the voltage stabilizing didoe (ZD1) in parallel with described the 3rd resistance (R3).
5. power supply protection circuit according to claim 1, is characterized in that, described controller comprises MCU and control circuit.
6. power supply protection circuit according to claim 5, is characterized in that, described control circuit comprises triode (Q2), and the collector electrode of described triode (Q2) connects described switching circuit, grounded emitter, and base stage is connected to the output of described MCU.
7. power supply protection circuit according to claim 1, is characterized in that, described switching circuit comprises MOS switching tube (Q1).
8. power supply protection circuit according to claim 1, is characterized in that, described switching circuit also comprises soft the opening that be connected with described MOS switching tube (Q1)/soft shut-off circuit.
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201220580277 CN202930901U (en) | 2012-11-06 | 2012-11-06 | Power supply protection circuit for liquid crystal screen TCON plate |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220580277 CN202930901U (en) | 2012-11-06 | 2012-11-06 | Power supply protection circuit for liquid crystal screen TCON plate |
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| CN202930901U true CN202930901U (en) | 2013-05-08 |
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| CN 201220580277 Expired - Fee Related CN202930901U (en) | 2012-11-06 | 2012-11-06 | Power supply protection circuit for liquid crystal screen TCON plate |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105528208A (en) * | 2015-12-04 | 2016-04-27 | 四川长虹电器股份有限公司 | TCON-less screen parameter separation control method |
| CN106786461A (en) * | 2016-12-29 | 2017-05-31 | 广东威创视讯科技股份有限公司 | A kind of voltage is counter to fill process circuit |
-
2012
- 2012-11-06 CN CN 201220580277 patent/CN202930901U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105528208A (en) * | 2015-12-04 | 2016-04-27 | 四川长虹电器股份有限公司 | TCON-less screen parameter separation control method |
| CN105528208B (en) * | 2015-12-04 | 2019-02-05 | 四川长虹电器股份有限公司 | TCON-less screen joins separation control method |
| CN106786461A (en) * | 2016-12-29 | 2017-05-31 | 广东威创视讯科技股份有限公司 | A kind of voltage is counter to fill process circuit |
| CN106786461B (en) * | 2016-12-29 | 2019-05-07 | 广东威创视讯科技股份有限公司 | A kind of voltage is counter to fill processing circuit |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130508 Termination date: 20171106 |
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| CF01 | Termination of patent right due to non-payment of annual fee |