CN103596322B - A kind of constant current comparison circuit for LED drive circuit - Google Patents
A kind of constant current comparison circuit for LED drive circuit Download PDFInfo
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- CN103596322B CN103596322B CN201210298581.2A CN201210298581A CN103596322B CN 103596322 B CN103596322 B CN 103596322B CN 201210298581 A CN201210298581 A CN 201210298581A CN 103596322 B CN103596322 B CN 103596322B
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Abstract
A kind of constant current comparison circuit for LED drive circuit, including the first sampling resistor, the second sampling resistor, the first gain adjustment module, the second gain adjustment module, the first indicating module, the second indicating module and voltage amplification module.The above-mentioned constant current comparison circuit for LED drive circuit is sampled the voltage of the first LED light group and the second LED light group respectively by the first sampling resistor and the second sampling resistor, and by the control source of sampling to voltage amplification module, and the first gain adjustment module and the second gain adjustment module being connected with voltage amplification module can adjust the gain amplifier of voltage amplification module, the first indicating module and the second indicating module is allowed to show the voltage difference between the first LED light group and the second LED light group so as to provide enough voltage, and then can interpolate that the higher lamp group of electric current in the first LED light group and the second LED light group.
Description
Technical field
The present invention relates to current comparison circuit, more particularly to a kind of constant current comparison circuit for LED drive circuit.
Background technology
LED light group in the market is using generally in LED display, and general every LED light group is all using independent
Drive circuit, therefore, the electric current of every LED light group can have certain deviation.When current deviation exceedes certain limit, it can make
It is uneven into luminous intensity distribution, so that the leading aged deterioration of the LED light group for causing electric current too high, and then influence making for whole LED display
Use the life-span.
The content of the invention
Based on this, it is necessary to provide a kind of constant current ratio for LED drive circuit that can show that LED light group electric current is higher
Compared with circuit.
A kind of constant current comparison circuit for LED drive circuit, including the first sampling resistor, the second sampling resistor, first
Gain adjustment module, the second gain adjustment module, the first indicating module, the second indicating module and voltage amplification module；
Described first sampling resistor one end is used to be connected with the first LED light group, other end ground connection；
Described second sampling resistor one end is used to be connected with the second LED light group, other end ground connection；
The input of first gain adjustment module and first sampling resistor and first LED light group it is public
End connection, the control end of first gain adjustment module is connected with the inverting input of the voltage amplification module, and described the
The output end of one gain adjustment module is connected with the output end of the voltage amplification module；
The input of second gain adjustment module and first sampling resistor and second LED light group it is public
End connection, the control end of second gain adjustment module is connected with the normal phase input end of the voltage amplification module, and described the
The output head grounding of two gain adjustment modules；
First indicating module is connected with second indicating module, and first indicating module is indicated with described second
One common port of module is connected with the output end of the voltage amplification module, another common end grounding.
In wherein one embodiment, first gain adjustment module includes divider resistance R3 and divider resistance R5, institute
State divider resistance R3 one end to be connected with the divider resistance R5, the other end of the divider resistance R3 is first gain-adjusted
The input of module, the other end of the divider resistance R5 is the output end of first gain adjustment module, the partial pressure electricity
The common port for hindering the R3 and divider resistance R5 is the control end of first gain adjustment module.
In wherein one embodiment, second gain adjustment module includes divider resistance R4 and divider resistance R6, institute
State divider resistance R4 one end to be connected with the divider resistance R6, the other end of the divider resistance R4 is second gain-adjusted
The input of module, the other end of the divider resistance R6 is the output end of second gain adjustment module, the partial pressure electricity
The common port for hindering the R4 and divider resistance R6 is the control end of second gain adjustment module.
In wherein one embodiment, the voltage amplification module is operational amplifier U1B, the operational amplifier U1B
Normal phase input end be the voltage amplification module normal phase input end, the inverting input of the operational amplifier U1B is institute
The inverting input of voltage amplification module is stated, the output end of the operational amplifier U1B is the output of the voltage amplification module
End.
In wherein one embodiment, first indicating module is LED7, and second indicating module is LED8, described
LED7 negative electrode is connected with the anode of the LED8, and the negative electrode of the LED8 is connected with the anode of the LED7, the LED7 and
A common port of the LED8 is connected with the output end of the voltage amplification module, and the LED7 and the LED8's is another public
End ground connection.
In wherein one embodiment, also including current-limiting resistance R7, the current-limiting resistance R7 is series at the voltage amplification
Between one common port of the output end of module and first indicating module and second indicating module.
The above-mentioned constant current comparison circuit for LED drive circuit is adopted respectively by the first sampling resistor and the second sampling resistor
The voltage of the LED light group of sample first and the second LED light group, and by the control source of sampling to voltage amplification module, and put with voltage
The first gain adjustment module and the second gain adjustment module of big module connection can adjust the gain amplifier of voltage amplification module,
The first indicating module and the second indicating module is allowed to show the first LED light group and the second LED so as to provide enough voltage
Voltage difference between group, and then can interpolate that the higher lamp group of electric current in the first LED light group and the second LED light group.
It can show that LED light group electric current is higher further, it would be desirable to provide a kind of and higher LED light group driving current can be adjusted
LED light group current monitoring device.
A kind of LED light group current monitoring device, including above-mentioned constant current comparison circuit for LED drive circuit, collection mould
Block and feedback control module, the acquisition module and the constant current comparison circuit for LED drive circuit and the feedback control
Molding block is connected, and the feedback control module is connected with the constant current comparison circuit for LED drive circuit,
The acquisition module is used for the output signal for gathering the constant current comparison circuit of the LED drive circuit, and will collection
Output signal be transferred to the feedback control module, the feedback control module is used according to the control of the output signal of reception is described
The voltage of the first LED light group and the second LED light group two ends in the constant current comparison circuit of LED drive circuit.
Above-mentioned LED light group current monitoring device judges that LED light group is by the constant current comparison circuit for LED drive circuit
No electric current is higher and is shown by the first indicating module and the second indicating module, acquisition module collection the first indicating module and second
The output signal of indicating module, and the output signal of collection is transferred to feedback control module, feedback control module is according to reception
Output signal control the voltage at the first LED light group and the second LED light group two ends.So as to above-mentioned LED light group current monitoring device
It ensure that LED light group in time can reduce higher electric current when electric current is higher, it is to avoid LED light group luminous intensity distribution is uneven and causes
Lamp group aged deterioration.
Brief description of the drawings
Fig. 1 is the module map of the constant current comparison circuit for LED drive circuit；
Fig. 2 is the module map of LED light group current monitoring device；
Fig. 3 is the schematic diagram of the constant current comparison circuit for LED drive circuit.
Embodiment
As shown in figure 1, being the constant current comparison circuit for LED drive circuit.A kind of constant current ratio for LED drive circuit
Compared with circuit, including the first sampling resistor 101, the second sampling resistor 103, the first gain adjustment module 105, the second gain-adjusted mould
Block 107, the first indicating module 109, the second indicating module 111 and voltage amplification module 113.
The one end of first sampling resistor 101 is used to be connected with the first LED light group, other end ground connection.
The one end of second sampling resistor 103 is used to be connected with the second LED light group, other end ground connection.
The input of first gain adjustment module 105 and the first sampling resistor 101 and the common port of the first LED light group connect
Connect, the control end of the first gain adjustment module 105 is connected with the inverting input of voltage amplification module 113, the first gain-adjusted
The output end of module 105 is connected with the output end of voltage amplification module 113.
The input of second gain adjustment module 107 and the first sampling resistor 101 and the common port of the second LED light group connect
Connect, the control end of the second gain adjustment module 107 is connected with the normal phase input end of voltage amplification module 113, the second gain-adjusted
The output head grounding of module 107.
First indicating module 109 is connected with the second indicating module 111, the first indicating module 109 and the second indicating module 111
A common port be connected with the output end of voltage amplification module 113, another common end grounding.
First sampling resistor 101 and the second sampling resistor 103 are respectively the electric current of the first LED light group and the second LED light group
Sampling resistor.
First gain module 105 and the second gain module 107 are increased for adjusting the voltage of voltage amplification module 113
Benefit, because LED needs constant current to drive, LED luminance can be influenceed when electric current is fluctuated, it is therefore desirable to by two groups of LED
The current deviation of lamp group is controlled in a small range, so using high-gain so that when current deviation occur in two groups of LED light groups, energy
It is enough to find in time, and adjust in controlled range the electric current of two groups of LED light groups.
Voltage amplification module 113 is used to amplify the sampling electricity of the first sampling resistor 101 and the second sampling resistor 102 between the two
The difference of pressure.And the difference of the sampled voltage of the first sampling resistor 101 and the second sampling resistor 102 between the two is sign first
The current differential of LED light group and the second LED light group between the two.Therefore, the sampled voltage amplified by voltage amplification module 113
Difference, can reflect the current differential of the first LED light group and the second LED light group between the two.
First indicating module 109 and the second indicating module 111 are used for the current bias of indication LED lamp group.When the first instruction
When module 109 sends indication signal, represent that the electric current of the first LED light group is higher, when the second indicating module 111 sends indication signal
When, represent that the electric current of the second LED light group is higher, when the first indicating module 109 and the second indicating module 111 do not send instruction letter
Number when, represent the electric current basis equalization of the first LED light group and the second LED light group.Therefore, the first indicating module 109 and are passed through
Two indicating modules 111 just can interpolate that whether the electric current of LED light group is higher, if higher, then can adjust higher LED in time
The electric current of group, it is to avoid electric current is higher to cause damage to LED light group.
Incorporated by reference to Fig. 2.
Specifically, the first sampling resistor is resistance R1, and the second sampling resistor is resistance R2.
First gain adjustment module 105 includes divider resistance R3 and divider resistance R5, divider resistance R3 one end and partial pressure electricity
R5 connections are hindered, the divider resistance R3 other end is the input of the first gain adjustment module 105, and the divider resistance R5 other end is
The output end of first gain adjustment module 105, divider resistance R3 and divider resistance R5 common port are the first gain adjustment module
105 control end.
Second gain adjustment module 107 includes divider resistance R4 and divider resistance R6, divider resistance R4 one end and partial pressure electricity
R6 connections are hindered, the divider resistance R4 other end is the input of the second gain adjustment module 107, and the divider resistance R6 other end is
The output end of second gain adjustment module 107, divider resistance R4 and divider resistance R6 common port are the second gain adjustment module
107 control end.
Voltage amplification module 113 is operational amplifier U1B, and operational amplifier U1B normal phase input end is voltage amplification mould
The normal phase input end of block 113, operational amplifier U1B inverting input is the inverting input of voltage amplification module 113, computing
Amplifier U1B output end is the output end of voltage amplification module 113.
First indicating module 109 is LED7, and the second indicating module 111 is LED8, and LED7 negative electrode and LED8 anode connect
Connect, LED8 negative electrode and LED7 anode are connected, and LED7 and LED8 a common port connect with the output end of voltage amplification module 113
Connect, LED7 and LED8 another common end grounding.
Constant current comparison circuit for LED drive circuit also includes current-limiting resistance R7, and current-limiting resistance R7 is series at voltage and put
Greatly between the output end of module 113 and a common port of the first indicating module 109 and the second indicating module 111.
In the present embodiment, the first sampling resistor 101 is equal with the resistance of the second sampling resistor 103, the first gain-adjusted
The resistance of the gain adjustment module 107 of module 105 and second is also equal.Specifically, i.e. R1=R2, R3=R4, R5=R6.Generally subtract
The power consumption of small circuit, resistance R1 and resistance R2 resistance are smaller.
Based on above-mentioned all embodiments, the operation principle for the constant current comparison circuit of LED drive circuit is as follows：
The pressure drop V1 and V2 of equivalence can be produced when the electric current of two LED light groups passes through resistance R1 and resistance R2.Ear two
The operating current of bar LED light group is of substantially equal, i.e., when the current differential of two paths of LED lamp group is no more than 5%, even if current differential is passed through
After by voltage amplification module 113 being amplified, also it is not enough to light LED7 or LED8 via the voltage exported after current-limiting resistance R7.
When the electric current on the electric current ratio resistance R2 on resistance R1 it is big 5% when, according to the amplification formula of voltage amplification module 113
V0=（V1-V2）* R5/R3, can calculate the output voltage of voltage amplification module 113, and R5/R3 value is by setting in advance
Put, as long as the difference between i.e. V1 and V2 is more than 5%, output voltage V0 is enough to light LED7.
When resistance R1 electric current ratio resistance R2 electric current it is small 5% when, principle is ibid.
After LED7 or LED8 are lit, LED brightness is higher, represents that the current differential between two groups of LED light groups is bigger.
In one embodiment, it is assumed that the operating current of two LED light groups is designed as 700mA, R5=560K Ω, R3=10K
Ω, passes through R1/R2（0.1Ω）When, then V1/V2 is 700*0.2=140mV, due to V1=V2, Vo=0V, LED7 and LED8 not
It is bright, represent the current difference of two LED light groups not less than 5%.When two LED operating current difference is more than 5%, such as V2 electricity
Pressure is more than V1, after voltage amplification module 113, output voltage Vo=（700-700*0.95）* 560/1=1.96V, this positive voltage
LED8 is just lighted, if V1 is more than V2, after voltage amplification module 113, output voltage Vo=（700-700*1.05）*
560/1=-1.96V, negative voltage just lights LED7.
The above-mentioned constant current comparison circuit for LED drive circuit is adopted respectively by the first sampling resistor and the second sampling resistor
The voltage of the LED light group of sample first and the second LED light group, and by the control source of sampling to voltage amplification module, and put with voltage
The first gain adjustment module and the second gain adjustment module of big module connection can adjust the gain amplifier of voltage amplification module,
The first indicating module and the second indicating module is allowed to show the first LED light group and the second LED so as to provide enough voltage
Voltage difference between group, and then can interpolate that the higher lamp group of electric current in the first LED light group and the second LED light group.
As shown in figure 3, being the module map of LED light group current monitoring device.A kind of LED light group current monitoring device, including
Above-mentioned constant current comparison circuit 10, acquisition module 20 and feedback control module 30 for LED drive circuit, acquisition module 20 is with using
Connected in the constant current comparison circuit 10 and feedback control module 30 of LED drive circuit, feedback control module 30 for LED with driving
The constant current comparison circuit 10 of circuit is connected,
Acquisition module 20 is used for the output signal for gathering the constant current comparison circuit 10 of LED drive circuit, and by the defeated of collection
Go out signal transmission to feedback control module 30, feedback control module 30 controls to be used for LED driving electricity according to the output signal of reception
The voltage of the first LED light group and the second LED light group two ends in the constant current comparison circuit 10 on road.
Above-mentioned LED light group current monitoring device judges LED light group by the constant current comparison circuit 10 for LED drive circuit
Whether electric current is higher and shown by the first indicating module 109 and the second indicating module 111, and the collection of acquisition module 20 first is indicated
The output signal of the indicating module 111 of module 109 and second, and the output signal of collection is transferred to feedback control module 30, instead
Present the voltage that control module 30 controls the first LED light group and the second LED light group two ends according to the output signal of reception.If first refers to
Show that the LED7 in module 109 is lighted, then feedback control module 30 controls the driving current of the first LED light group to reduce, if second refers to
Show that the LED8 in module 111 is lighted, then feedback control module 30 controls the driving current of the first LED light group to reduce.If first refers to
Show the non-output signal of the indicating module 111 of module 109 and first, then it represents that two LED light groups are working properly.
So as to which above-mentioned LED light group current monitoring device ensure that LED light group can in time will be higher when electric current is higher
Electric current reduce, it is to avoid LED light group luminous intensity distribution is uneven and causes lamp group aged deterioration.
Embodiment described above only expresses the several embodiments of the present invention, and it describes more specific and detailed, but simultaneously
Therefore the limitation to the scope of the claims of the present invention can not be interpreted as.It should be pointed out that for one of ordinary skill in the art
For, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to the guarantor of the present invention
Protect scope.Therefore, the protection domain of patent of the present invention should be determined by the appended claims.
Claims (6)
1. a kind of constant current comparison circuit for LED drive circuit, it is characterised in that including the first sampling resistor, the second sampling
Resistance, the first gain adjustment module, the second gain adjustment module, the first indicating module, the second indicating module and voltage amplification mould
Block；
Described first sampling resistor one end is used to be connected with the first LED light group, other end ground connection；
Described second sampling resistor one end is used to be connected with the second LED light group, other end ground connection；
The input of first gain adjustment module connects with first sampling resistor and the common port of first LED light group
Connect, the control end of first gain adjustment module is connected with the inverting input of the voltage amplification module, described first increases
The output end of beneficial adjustment module is connected with the output end of the voltage amplification module；
The input of second gain adjustment module connects with first sampling resistor and the common port of second LED light group
Connect, the control end of second gain adjustment module is connected with the normal phase input end of the voltage amplification module, described second increases
The output head grounding of beneficial adjustment module；
First indicating module is connected with second indicating module, first indicating module and second indicating module
A common port be connected with the output end of the voltage amplification module, another common end grounding；
First indicating module is LED7, and second indicating module is LED8, and the negative electrode of the LED7 is with the LED8's
Anode is connected, and the negative electrode of the LED8 is connected with the anode of the LED7, the LED7 and the LED8 common port and institute
State another common end grounding of the output end connection of voltage amplification module, the LED7 and the LED8.
2. the constant current comparison circuit according to claim 1 for LED drive circuit, it is characterised in that described first increases
Beneficial adjustment module includes divider resistance R3 and divider resistance R5, and described divider resistance R3 one end is connected with the divider resistance R5,
The other end of the divider resistance R3 is the input of first gain adjustment module, and the other end of the divider resistance R5 is
The output end of first gain adjustment module, the divider resistance R3 and the divider resistance R5 common port are described first
The control end of gain adjustment module.
3. the constant current comparison circuit according to claim 1 for LED drive circuit, it is characterised in that described second increases
Beneficial adjustment module includes divider resistance R4 and divider resistance R6, and described divider resistance R4 one end is connected with the divider resistance R6,
The other end of the divider resistance R4 is the input of second gain adjustment module, and the other end of the divider resistance R6 is
The output end of second gain adjustment module, the divider resistance R4 and the divider resistance R6 common port are described second
The control end of gain adjustment module.
4. the constant current comparison circuit according to claim 1 for LED drive circuit, it is characterised in that the voltage is put
Module is that the positive that operational amplifier U1B, the operational amplifier U1B normal phase input end are the voltage amplification module is defeated greatly
Enter end, the inverting input of the operational amplifier U1B is the inverting input of the voltage amplification module, the operation amplifier
Device U1B output end is the output end of the voltage amplification module.
5. the constant current comparison circuit according to claim 1 for LED drive circuit, it is characterised in that also including current limliting
Resistance R7, the current-limiting resistance R7 are series at the output end and first indicating module of the voltage amplification module and described the
Between one common port of two indicating modules.
6. a kind of LED light group current monitoring device, it is characterised in that including being used for LED as described in claim 1-5 any one
Constant current comparison circuit, acquisition module and the feedback control module of drive circuit, the acquisition module drive electricity with the LED that is used for
The constant current comparison circuit on road and feedback control module connection, the feedback control module are used for LED drive circuit with described
Constant current comparison circuit connection,
The acquisition module is used for the output signal for gathering the constant current comparison circuit of the LED drive circuit, and by the defeated of collection
Go out signal transmission to the feedback control module, the feedback control module is used for according to being controlled the output signal of reception
The voltage of the first LED light group and the second LED light group two ends in the constant current comparison circuit of LED drive circuit.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201210298581.2A CN103596322B (en) | 2012-08-16 | 2012-08-16 | A kind of constant current comparison circuit for LED drive circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210298581.2A CN103596322B (en) | 2012-08-16 | 2012-08-16 | A kind of constant current comparison circuit for LED drive circuit |
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| CN103596322A CN103596322A (en) | 2014-02-19 |
| CN103596322B true CN103596322B (en) | 2017-07-14 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104267249A (en) * | 2014-10-09 | 2015-01-07 | 长智光电（四川）有限公司 | Device for measuring voltage difference between LED string lights |
| CN104375549B (en) * | 2014-10-30 | 2016-08-31 | 中国电子科技集团公司第三十六研究所 | A kind of anti-latch circuit of cmos device |
| CN108375634A (en) * | 2018-01-31 | 2018-08-07 | 苏州智能制造研究院有限公司 | A kind of difference frequency continuation sinusoidal radiating circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201967204U (en) * | 2011-01-07 | 2011-09-07 | 英飞特电子（杭州）有限公司 | Multi-output constant-current driving circuit of light-emitting diode |
| CN201967183U (en) * | 2010-10-22 | 2011-09-07 | 英飞特电子（杭州）有限公司 | LED multi-way output current-sharing circuit |
| CN102256421A (en) * | 2011-07-28 | 2011-11-23 | 林万炯 | High-precision multipath LED (light-emitting diode) current-equalizing circuit |
| CN202143271U (en) * | 2011-07-28 | 2012-02-08 | 林万炯 | High accuracy multipath LED current sharing circuit |
-
2012
- 2012-08-16 CN CN201210298581.2A patent/CN103596322B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201967183U (en) * | 2010-10-22 | 2011-09-07 | 英飞特电子（杭州）有限公司 | LED multi-way output current-sharing circuit |
| CN201967204U (en) * | 2011-01-07 | 2011-09-07 | 英飞特电子（杭州）有限公司 | Multi-output constant-current driving circuit of light-emitting diode |
| CN102256421A (en) * | 2011-07-28 | 2011-11-23 | 林万炯 | High-precision multipath LED (light-emitting diode) current-equalizing circuit |
| CN202143271U (en) * | 2011-07-28 | 2012-02-08 | 林万炯 | High accuracy multipath LED current sharing circuit |
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