CN209248376U - A kind of short-circuit protection circuit - Google Patents
A kind of short-circuit protection circuit Download PDFInfo
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- CN209248376U CN209248376U CN201920201365.9U CN201920201365U CN209248376U CN 209248376 U CN209248376 U CN 209248376U CN 201920201365 U CN201920201365 U CN 201920201365U CN 209248376 U CN209248376 U CN 209248376U
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Abstract
The utility model discloses a kind of short-circuit protection circuits, are related to backlight drive technical field.The circuit includes: backlight load, further includes: driving boost module, constant current detection module and detection protective module, the load input terminal for driving the voltage output end of boost module to load with backlight are connected；The voltage input end of constant current detection module is connected with the load outputs that backlight loads, and first voltage output end is connected with the feedback signal input terminal of driving boost module, second voltage output end ground connection；The protection input terminal of detection protective module is connected with the voltage input end of constant current detection module; protection output end is connected with the first voltage output end of constant current detection module or second voltage output end; when load input terminal for loading when backlight and load outputs short circuit, reduce input constant current detection module short circuit current.Solve the problems, such as that device damages due to short-circuit generation instantaneous large-current in constant current driver circuit, realizes the protection to constant current detection module using the circuit.
Description
Technical field
The utility model relates to backlight drive technical field more particularly to a kind of short-circuit protection circuits.
Background technique
In normal work, operating current has to more stable LED light bar, not so can damage LED light bar.Therefore,
Existing LED light bar mostly uses greatly the boost type LED constant current driver circuit of simulation dimming mode, makes to export to the electric current of LED light bar
For constant current value.
The boost type LED constant current driver circuit of existing simulation dimming mode includes boost module and backlight load (LED light
Item), output after tens volts of boost in voltage of input are more than 100 volts or are higher by boost module.Since output end is user's use
End, unavoidably will appear the abnormal conditions of output short-circuit.When exporting terminal shortcircuit, due to entirely simulating the boosting of dimming mode
Formula LED constant current driver circuit impedance very little, so that generating tens amperes or bigger of immediate current in circuit, it is easy to lead to device
Part is because heavy current impact damages.Therefore, how to inhibit simulate dimming mode boost type LED constant current driver circuit in device because
Short circuit generate instantaneous large-current and damage and be a problem to be solved.
Utility model content
A kind of short-circuit protection circuit provided by the utility model efficiently solves device in constant current driver circuit and produces because short-circuit
The problem of giving birth to instantaneous large-current and damaging.
The utility model embodiment provides a kind of short-circuit protection circuit, comprising:
Backlight load, further includes: driving boost module, constant current detection module and detection protective module,
The voltage output end of the driving boost module is connected with the load input terminal that the backlight loads, and is used for described
Voltage after backlight load output boosting；
The voltage input end of the constant current detection module is connected with the load outputs that the backlight loads, and first voltage is defeated
Outlet is connected with the feedback signal input terminal of the driving boost module, and second voltage output end ground connection is used for the driving
Boost module feeds back whether the backlight load is constant current output；
The protection input terminal of the detection protective module is connected with the voltage input end of the constant current detection module, protects defeated
Outlet is connected with the first voltage output end of the constant current detection module or second voltage output end, for loading when the backlight
Load input terminal and when load outputs short circuit, reduce and input the constant current detection module short circuit current.
The utility model embodiment provides a kind of short-circuit protection circuit.Using above-mentioned technical proposal, driving can be passed through
Boost module and constant current detection module load for backlight provides constant current.When backlight load short circuits, generated in circuit loop
Biggish short circuit current, due to the voltage input end phase of the protection input terminal and the constant current detection module of detection protective module
Even, protection output end is connected with the first voltage output end of the constant current detection module or second voltage output end, effectively reduces
The electric current for flowing through constant current detection module, realizes the protection to constant current detection module.Through carrying out verification experimental verification, board in board
Output voltage 180V when normal work, if detection protective module is not added, when backlight load short circuits, constant current detection module is at once
Overcurrent punch through damage, spoilage are up to 100%.After increasing detection protective module, same short-circuit test is done, repeatedly more than 20
Secondary, constant current detection module will not all damage.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of one of the utility model embodiment one short-circuit protection circuit；
Fig. 2 is the circuit diagram of one of the utility model embodiment one short-circuit protection circuit；
Fig. 3 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one；
Fig. 4 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one；
Fig. 5 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one；
Fig. 6 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one；
Fig. 7 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one.
Specific embodiment
The utility model is described in further detail with reference to the accompanying drawings and examples.It is understood that herein
Described specific embodiment is used only for explaining the utility model, rather than the restriction to the utility model.It further needs exist for
It is bright, part relevant to the utility model is illustrated only for ease of description, in attached drawing rather than entire infrastructure.
Embodiment one
Fig. 1 is the structural schematic diagram of one of the utility model embodiment one short-circuit protection circuit, and the present embodiment can fit
The case where for carrying out short-circuit protection to device in constant current driver circuit, such as constant current detection module in constant current driver circuit is carried out
The case where short-circuit protection.
Although existing LED constant current driver circuit itself (control IC) part has had the protection function of output overcurrent and short circuit
Can, but the short-circuit protection function for controlling IC is started after detecting transcient short circuit time high current.From detecting high current signal
Certain delay is needed to short-circuit protection is executed, so the short-circuit protection function of control IC itself can not effectively inhibit short-circuit wink
Between high current.
Short-circuit protection circuit can effectively solve the problem that device in constant current driver circuit by detecting protective module in the present embodiment
The problem of being damaged because of short circuit.As shown in Figure 1, a kind of short-circuit protection circuit that the utility model embodiment one provides, comprising:
Backlight load 11, further includes: driving boost module 12, constant current detection module 13 and detection protective module 14,
The voltage output end of boost module 12 and the load input terminal of backlight load 11 is driven to be connected, for loading to backlight
Voltage after 11 output boostings；
The voltage input end of constant current detection module 13 is connected with the load outputs of backlight load 11, first voltage output end
It is connected with the feedback signal input terminal of driving boost module 12, second voltage output end ground connection is used for driving boost module 12
Feed back whether backlight load 11 is constant current output；
The protection input terminal of detection protective module 14 is connected with the voltage input end of constant current detection module 13, protects output end
It is connected with the first voltage output end of constant current detection module 13 or second voltage output end, the load for loading 11 when backlight is defeated
When entering end and load outputs short circuit, reduce input 13 short circuit current of constant current detection module.
In the present embodiment, the working principle of the short-circuit protection circuit is: the load input terminal of backlight load 11, which receives, to be driven
Voltage after the boosting of the voltage output end output of dynamic boost module 12, since backlight load 11 mentions in normal work for circuit
For certain impedance, so that the electric current in circuit is direct current constant value.The voltage input end and backlight of constant current detection module 13 are negative
The load outputs of load 11 are connected, second voltage output end ground connection, then pass through first voltage output end and drive boost module
12 feedback signal input terminals are connected, to feed back whether backlight load 11 is constant current output to driving boost module 12.Detection is protected
The protection input terminal of shield module 14 is connect with the voltage input end of constant current detection module 13, the protection output of detection protective module 14
End is connected with the first voltage output end of constant current detection module 13 or second voltage output end, thus when the load of backlight load 11
When input terminal and load outputs short circuit, detection protective module 14 and constant current detection module 13 are shunted, and flow through constant current to reduce
The electric current of detection module 13, to realize the protection to constant current detection module 13.
In the present embodiment, backlight load 11 can be understood as providing the device of brightness, backlight load 11 to display equipment
Luminous intensity can determine display equipment brightness.In backlight 11 work of load, operating current will keep stable, not so
It is easily damaged backlight load 11.Driving boost module 12 can be understood as loading 11 offer voltages to backlight, so that backlight loads
The constant module of 11 electric current.Constant current detection module 13 can be understood as the whether constant mould of electric current of detection backlight load 11
Block.The signal that driving boost module 12 can be fed back based on constant current detection module 13 keeps the electric current of backlight load 11 constant.Detection
Protective module 14 can be understood as the module that short-circuit protection is carried out to constant current detection module 13.
Wherein, backlight load 11 can connect the LED light bar to be formed for N number of LED light；N is the positive integer greater than 1.Driving
Boost module 12 is connected by voltage output end with the load input terminal of backlight load 11, and backlight loads 11 load outputs and perseverance
The voltage input end for flowing detection module 13 is connected, and is then grounded by the second voltage output end of constant current detection module 13, thus
Pressure drop is generated in backlight load 11.
13 voltage input end of constant current detection module is connected with the load outputs of backlight load 11, second voltage output termination
Ground, first voltage output end are connected with the feedback signal input terminal of driving boost module 12, to the driving feedback back of boost module 12
Whether the electric current of light load 11, the electric current to judge backlight load 11 are constant.If the electric current of backlight load 11 is non-constant, driving
Boost module 12 can be adjusted the voltage of backlight load 11 by the data detected, to guarantee constant current output.
It is understood that loading the difference of 11 quantity according to backlight, constant current detection module 13 may include different device
Part.Illustratively, if backlight load 11 is one, constant current detection module 13 can be set to resistance, and (resistance value can basis
Actual conditions are set), the voltage value by detecting the resistance determines the current value for flowing through backlight load 11；If backlight is negative
Carrying 11 is at least two, and constant current detection module 13 may include flowing unit and detection unit.Stream unit can the road Shi Ge back
Light 11 electric currents of load are identical, and detection unit is determined for whether each backlight load 11 is constant current output.Wherein, detection unit
It can be set to resistance (resistance value can be set according to the actual situation).
It is understood that can be several ohm or smaller since 13 resistance value of constant current detection module is smaller, thus it is short in circuit
Lu Shi, constant current detection module 13 are easy to be damaged.Therefore in the present embodiment, can will test the protection input terminal of protective module 14 with
The voltage input end of constant current detection module 13 is connected, the first voltage output end of protection output end and constant current detection module 13 or the
Two voltage output ends are connected, and to shunt with constant current detection module 13, realize the protection to constant current detection module 13.In addition, ability
Constant current detection module 13 can be connected in parallel to random devices both ends according to demand by field technique personnel, to carry out short-circuit guarantor to the device
Shield.
A kind of short-circuit protection circuit is present embodiments provided, it is negative for backlight by driving boost module and constant current detection module
It carries and constant current is provided.When backlight load short circuits, biggish short circuit current is generated in circuit loop, due to detecting protective module
Protection input terminal be connected with the voltage input end of the constant current detection module, protection output end and the constant current detection module
First voltage output end or second voltage output end are connected, and effectively reduce the electric current for flowing through constant current detection module, realize pair
The protection of constant current detection module.Through the output voltage 180V when board carries out verification experimental verification, and board works normally, if inspection is not added
Protective module is surveyed, when backlight load short circuits, constant current detection module horse back overcurrent punch through damage, spoilage is up to 100%.Work as increasing
After adding detection protective module, same short-circuit test is done, more than 20 times repeatedly, constant current detection module will not all damage.
Fig. 2 is the circuit diagram of one of the utility model embodiment one short-circuit protection circuit.Further, when backlight is negative
When to carry 11 numbers be 1, constant current detection module 13 is first resistor R1, the first end of first resistor R1 as voltage input end with
First voltage output end, second end is as second voltage output end.
As shown in Fig. 2, first resistor R1 is used to feed back whether backlight load 11 is constant current output to driving boost module 12.
When backlight load 11 be 1 when, it can be understood as the short-circuit protection circuit be export all the way, therefore can be set first resistor R1 into
Row constant current detection.Specifically, it drives the voltage output end of boost module 12 to load 11 load input terminal LED+ with backlight to be connected, carry on the back
Light loads 11 load outputs LED- and is connected with first resistor R1 first end, the connection of load outputs LED- and first resistor R1
It holds and is connected with the feedback signal input terminal LED_FB of driving boost module 12, to feed back first resistor R1 to driving boost module 12
Voltage.Drive the feedback signal input terminal LED_FB of boost module 12 according to the voltage and resistance value of first resistor R1, it can be true
Determine the electric current of first resistor R1, the i.e. electric current (backlight load 11 is connected with first resistor R1) of backlight load 11, so that it is determined that back
Whether light load 11 is constant current output.
Fig. 3 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one.In the base of above-mentioned optimization
On plinth, when it is at least two that backlight, which loads 11 numbers, constant current detection module 13 includes second resistance R2 and flows unit 2；Flow
The number of unit 2 is identical as the number of backlight load 11；It is each flow unit 2 stream input terminal as voltage input end with it is corresponding
Backlight load 11 load outputs be connected, it is each flow unit 2 stream output end be shorted after as first voltage output end with
The first end of second resistance R2 is connected, for adjusting the output electric current of corresponding backlight load 11, so that 11 output of each backlight load
Electric current is identical；The second end of second resistance R2 is as second voltage output end, for feeding back each backlight to driving boost module 12
Whether the total current of load 11 is constant current output.
As shown in figure 3, when the number of backlight load 11 is at least two, it is believed that short-circuit protection circuit is that at least 2 roads are defeated
Out.Each backlight load 11 can be made of n light emitting diode, and each light emitting diode can have identical parameter.The first via
Middle backlight load 11 can be made of first the second light emitting diode of light emitting diode D11 ... D1n.Backlight loads in second tunnel
11 can be made of the 4th light emitting diode D2n of third light emitting diode D21 ....
It when short-circuit protection circuit includes at least two backlight load 11, is flowed for the road Shi Ge backlight load 11, constant current detection
Module 13 includes second resistance R2 and flows unit 2.It is identical to flow number and backlight 11 numbers of load of unit 2, each stream is single
Member 2 is connected between second resistance R2 and corresponding backlight load 11, is loaded 11 electric currents to adjust corresponding backlight, is kept each backlight negative
It is identical to carry 11 output electric currents.
It is understood that each stream unit 2 can be made of identity unit, can also be made of different components, as long as
It is identical to can be realized each 11 output electric current of road backlight load.Illustratively, each stream unit 2 can pass through coupling inductance reality
The now stream of each backlight load 11.
The first end of second resistance R2 can be used as first voltage output end and drive the feedback signal of boost module 12 defeated
Enter end to be connected, to drive boost module 12 that can obtain the voltage value of second resistance R2, then according to the electricity of second resistance R2
Pressure value and resistance value determine the electric current of second resistance R2, which can be the total current of each backlight load 11.Drive boost module
12 by monitor the total current of each backlight load 11 it is whether constant can determine each backlight load 11 whether constant current.
Further, the number for detecting protective module 14 is identical as stream 2 numbers of unit, each guarantor for detecting protective module 14
It protects input terminal to be connected with the corresponding stream input terminal for flowing unit 2, protects the first end or second of output end and second resistance R2
The second end of resistance R2 is connected.
As shown in figure 3, respectively detecting the protection input terminal of protective module 14 and the stream input terminal phase of corresponding stream unit 2
Even, each protection output end for detecting protective module 14 is connected with the first end of second resistance R2.
Fig. 4 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one.As shown in figure 4, each inspection
The protection input terminal for surveying protective module 14 is connected with the corresponding stream input terminal for flowing unit 2, each guarantor for detecting protective module 14
Shield output end is connected with the second end of second resistance R2.
Further, the protection input terminal for detecting protective module 14 is connected with the first end of second resistance R2, protection output
End is connected with the second end of second resistance R2.
Fig. 5 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one.As shown in figure 5, detection
The protection input terminal of protective module 14 is connected with the first end of second resistance R2, detects the protection output end and the of protective module 14
The second end of two resistance R2 is connected, i.e. detection protective module 14 is connected in parallel on the both ends second resistance R2, realizes to second resistance R2's
Protection.Wherein, the number for detecting protective module 14 can be one.
Fig. 6 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one.As shown in fig. 6, into one
Step ground, stream unit 2 further include flowing subelement 21 and 3rd resistor 22；The input terminal of subelement 21 is flowed as stream unit
2 stream input terminal, output end are connect with one end of 3rd resistor 22, for adjusting the electric current of corresponding backlight load 11；Third
The other end of resistance 22 is as the stream output end for flowing unit 2, for monitoring the electric current of corresponding backlight load 11.
The input terminal for flowing subelement 21 is connected with corresponding backlight load 11, for adjusting the electricity of corresponding backlight load 11
Stream.Each particular circuit configurations for flowing subelement 21 are not construed as limiting, and can be made of identity unit, can also be by different components group
At as long as the electric current of corresponding backlight load 11 can be adjusted, so that each backlight 11 electric currents of load are identical.
3rd resistor 22 is connected serially between corresponding stream subelement 21 and second resistance R2, passes through the electricity for detecting 3rd resistor 22
Stream realizes the monitoring that 11 electric currents are loaded to backlight.
Further, detection protective module 14 is first capacitor；One end of first capacitor is as protection input terminal, the other end
As protection output end.
Referring to fig. 2, first capacitor is connected in parallel to the realization of the both ends first resistor R1 to the short-circuit protection of first resistor.Specifically
Ground, in normal work, it is assumed that the voltage on the load input terminal LED+ and load outputs LED- of backlight load 11 is 100V,
When 11 short circuit of backlight load (i.e. load input terminal LED+ and load outputs LED- short circuit) moment, the 100V of output will be added in
On first resistor R1.Due to (only several ohm or smaller, it is believed that be most crisp in entire circuit of first resistor R1 resistance value very little
Weak device), 100V voltage can generate a very big electric current and flow through first resistor R1 at this time.In addition, driving boost module 12
In output filter capacitor C1 on the energy that stores can also release, form a very big instantaneous peak current and flow through the
One resistance R1.
When the both ends first resistor R1 parallel connection first capacitor, due to the physical characteristic that capacitance voltage cannot be mutated, in short circuit
Moment, 100V voltage can first give first capacitor charging, and most of electric current can flow through first capacitor, and only fraction electric current flows through the
One resistance R1, to realize the protection to first resistor R1, avoids first resistor R1 so short circuit current can also greatly reduce
It is damaged.
Change the size of first capacitor, the adjustable ratio for flowing through first capacitor and first resistor R1 electric current.As it can be seen that only
It is low in cost, electric by the way that the protection to the device can be realized in a device both ends to be protected polarity free capacitor in parallel
Road it is simple and when making pcb board without increasing too many space.
It is understood that only illustrate when constant current detection module 13 is first resistor R1 (at this point it is possible to think short herein
It is to export all the way that circuit is protected on road) when, detect the working principle that protective module 14 protects constant current detection module 13.When constant current is examined
(as in Figure 3-5, short-circuit protection circuit may be considered multiple-channel output at this time, and each road is mutual when survey module 13 is other devices
It is independent), it is protected respectively per detection protective module 14 (such as first capacitor) can be increased all the way, first capacitor can be according to reality
Circuit conditions are added in the position of most fragile.As shown in figure 3, can will test protective module 14 be added in flow unit 2 per all the way
On.As shown in figure 4, can will test on all devices that protective module 14 is connected in parallel under backlight load 11, such as it is connected in parallel on and flows
Unit 2 and the both ends second resistance R2 can play a protective role when short circuit occurs for any road.As shown in figure 5, can will examine
It surveys protective module 14 and is connected in parallel on the both ends second resistance R2, realize the protection to second resistance R2.When constant current detection module 13 is it
When his device, working principle and first capacitor that detection protective module 14 protects constant current detection module 13 to first resistor R1 into
The principle of row short-circuit protection is identical, and details are not described herein.
Fig. 7 is the circuit diagram of another short-circuit protection circuit in the utility model embodiment one.As shown in fig. 7, into one
Step ground, driving boost module 12 include driving unit 121 and boosting unit 122；The signal output end GATE of driving unit 121 with
The controlled end of boosting unit 122 is connected, for exporting control signal to boosting unit 122；The boosting output end of boosting unit 122
As the voltage output end of driving boost module 12, for the voltage after being boosted according to control signal to 11 output of backlight load.
On the basis of above scheme, driving unit 121 further includes detection input LED_FB, detection input LED_FB
It is connected with first voltage output end, whether is constant current output for monitoring backlight load 11.
Driving unit 121 receives the external pwm signal provided, the isolation through over-drive unit 121 by outside port PWM
Control signal is exported to the controlled end of boosting unit 122 in signal output port GATE after amplification.Boosting unit 122 is according to the control
After signal processed boosts to tens volts of voltages of input boosting unit, by the boosting output end of boosting unit 122 to backlight
The voltage of more than 100 volt of 11 output of load.
More specifically, boosting unit 122 includes first switch tube Q1, the 4th resistance R4, the first inductance L1, diode
D1, the 5th resistance R5, the 6th resistance R6 and filter capacitor C1.Wherein, the 4th resistance R4 can be driving resistance, the 6th resistance R6
It can be sampling resistor.Since the 4th one end resistance R4 is defeated as the signal of the controlled end and driving unit 121 of boosting unit 122
Outlet GATE is connected, and the other end is connected with first switch tube Q1 control terminal.When signal output end GATE is supplied to the 4th resistance R4
When high level signal, voltage is increased to the conducting voltage up to first switch tube Q1 on the 4th resistance R4, first switch tube is connected
Q1.When signal output end GATE is supplied to the 4th resistance R4 low level signal, voltage on the 4th resistance R4 is added in lower than the
The conducting voltage of one switching tube Q1, first switch tube Q1 shutdown.
Wherein, the first inductance L1 can be energy storage inductor, and filter capacitor C1 can be storage capacitor.Driving unit 121 connects
It receives pwm signal and exports control signal and give first switch tube Q1.When controlling signal control first switch tube Q1 conducting, first
Tens volts of voltages of input are carried out energy storage by inductance L1.It is powered at this time from filter capacitor C1 to backlight load 11.Diode D1 is set
Electric current backflow can be effectively prevent between the first inductance L1 and filter capacitor C1 by setting.When control signal control first switch tube Q1 is closed
When disconnected, the first inductance L1 releases energy to 11 power supply of backlight load, and filter capacitor C1 charges at this time.Boosting unit 122 is logical
The high voltage (volt or higher more than 100) for meeting driving backlight load 11 can be exported after crossing energy storage boosting.
Since the 6th resistance R6 is connect with first switch tube Q1 output end, when first switch tube Q1 conducting, first is flowed through
The electric current of switching tube Q1 passes through the 6th resistance R6, and generates pressure drop on the 6th resistance R6.Generated pressure drop and first switch
Pipe Q1 electric current is proportional, therefore the current detecting end CS of driving unit 121 can be by the voltage on the 6th resistance R6 of detection to sentence
The size of electric current of the cutout through first switch tube Q1.When the controller of first switch tube Q1, driving unit 121 can be opened
Dynamic overcurrent protection, prevents first switch tube Q1 from damaging because of overcurrent.In addition, detection input LED_FB can monitor backlight load
11 electric current, if backlight loads 11 controllers, driving unit 121 can star overcurrent protection, entire circuit meeting
Constantly it is restarted.
Note that above are only the preferred embodiment and institute's application technology principle of the utility model.Those skilled in the art's meeting
Understand, the utility model is not limited to specific embodiment described here, is able to carry out for a person skilled in the art various bright
Aobvious variation, readjustment and substitution is without departing from the protection scope of the utility model.Therefore, although passing through above embodiments
The utility model is described in further detail, but the utility model is not limited only to above embodiments, is not departing from
It can also include more other equivalent embodiments in the case that the utility model is conceived, and the scope of the utility model is by appended
Scope of the claims determine.
Claims (9)
1. a kind of short-circuit protection circuit, comprising: backlight load, which is characterized in that further include: driving boost module, constant current detection
Module and detection protective module,
The voltage output end of the driving boost module is connected with the load input terminal that the backlight loads, and is used for the backlight
Voltage after load output boosting；
The voltage input end of the constant current detection module is connected with the load outputs that the backlight loads, first voltage output end
It is connected with the feedback signal input terminal of the driving boost module, second voltage output end ground connection, for boosting to the driving
Whether the load of backlight described in module feedback is constant current output；
The protection input terminal of the detection protective module is connected with the voltage input end of the constant current detection module, protects output end
It is connected with the first voltage output end of the constant current detection module or second voltage output end, for bearing when backlight load
When carrying input terminal and load outputs short circuit, reduces and input the constant current detection module short circuit current.
2. circuit according to claim 1, which is characterized in that when backlight load number is 1, the constant current inspection
Survey module is first resistor, and the first end of the first resistor is as the voltage input end and first voltage output end, second
End is used as the second voltage output end.
3. circuit according to claim 1, which is characterized in that when backlight load number is at least two, the perseverance
Stream detection module includes second resistance and flows unit；
The number for flowing unit is identical as the number that the backlight loads；Each stream input terminal conduct for flowing unit
The voltage input end is connected with the load outputs that corresponding backlight loads, after each stream output end for flowing unit is shorted
It is connected as the first voltage output end with the first end of the second resistance, for adjusting the output electricity of corresponding backlight load
Stream, so that each backlight load output electric current is identical；
The second end of the second resistance is as the second voltage output end, for feeding back each institute to the driving boost module
Whether the total current for stating backlight load is constant current output.
4. circuit according to claim 3, which is characterized in that the number of the detection protective module and the stream unit
Number is identical, and the protection input terminal of each detection protective module is connected with the corresponding stream input terminal for flowing unit, protects defeated
Outlet is connected with the second end of the first end of the second resistance or the second resistance.
5. circuit according to claim 3, which is characterized in that the protection input terminal and described the of the detection protective module
The first end of two resistance is connected, and protection output end is connected with the second end of the second resistance.
6. circuit according to claim 3, which is characterized in that the stream unit further includes flowing subelement and third electricity
Resistance；
The input terminal for flowing subelement is as the stream input terminal for flowing unit, output end and the 3rd resistor
One end connection, for adjusting the electric current of corresponding backlight load；
The other end of the 3rd resistor is as the stream output end for flowing unit, for monitoring the corresponding backlight load
Electric current.
7. circuit according to claim 1, which is characterized in that the detection protective module is first capacitor；Described first
One end of capacitor is as the protection input terminal, and the other end is as the protection output end.
8. circuit according to claim 1, which is characterized in that the driving boost module includes that driving unit and boosting are single
Member；
The signal output end of the driving unit is connected with the controlled end of the boosting unit, for exporting to the boosting unit
Control signal；
Voltage output end of the boosting output end of the boosting unit as the driving boost module, for according to the control
Signal loads the voltage after output boosting to the backlight.
9. circuit according to claim 8, which is characterized in that the driving unit further includes detection input, the inspection
The feedback signal input terminal that input terminal is surveyed as the driving boost module is connected with the first voltage output end, for monitoring
Whether the backlight load is constant current output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920201365.9U CN209248376U (en) | 2019-02-15 | 2019-02-15 | A kind of short-circuit protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920201365.9U CN209248376U (en) | 2019-02-15 | 2019-02-15 | A kind of short-circuit protection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN209248376U true CN209248376U (en) | 2019-08-13 |
Family
ID=67537158
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| Application Number | Title | Priority Date | Filing Date |
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| CN201920201365.9U Active CN209248376U (en) | 2019-02-15 | 2019-02-15 | A kind of short-circuit protection circuit |
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| Country | Link |
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2019
- 2019-02-15 CN CN201920201365.9U patent/CN209248376U/en active Active
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