CN203251462U - LED drive device capable of changing series-parallel composition along input voltage - Google Patents
LED drive device capable of changing series-parallel composition along input voltage Download PDFInfo
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- CN203251462U CN203251462U CN 201320157246 CN201320157246U CN203251462U CN 203251462 U CN203251462 U CN 203251462U CN 201320157246 CN201320157246 CN 201320157246 CN 201320157246 U CN201320157246 U CN 201320157246U CN 203251462 U CN203251462 U CN 203251462U
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Abstract
An LED drive device capable of dynamically changing series-parallel composition along input voltage comprises the following elements: an input voltage sensing module comparing the input voltage with different preset voltage scopes and outputting an input voltage state signal; a circuit series-parallel composition control module outputting corresponding control signals according to the input voltage state signal to a switch assembly and a constant current source capable of dynamically changing total current; the switch assembly capable of changing LED matrix series-parallel composition and dynamically changing the series-parallel composition of the LED matrix according to different control signals; and the constant current source capable of dynamically changing the total current. The constant current source is used for dynamically changing the total current of the constant current source according to different control signals so as to cooperate with the switch assembly, so the current on a single series LED path is kept in a constant current scope. The LED drive device capable of changing the series-parallel composition along input voltage can effectively solve the phenomenon of clear zone and dark zone of the LED lamp, and further reduces a stroboscopic problem of the LED lamp when a conventional drive with DC low voltage.
Description
Technical field
The utility model belongs to the electronic circuit control field, particularly a kind of LED drive unit that changes series parallel structure with input voltage.
Background technology
LED illumination is more and more universal, exists a lot of general LED to drive chips and module in the market, and the driving power of LED slowly forms the industry universal standard, often can intercommunication use between the driving power of various brands.
For the cost of the driving power that reduces LED, produced the LED drive unit of resistance-capacitance depressurization and the direct step-down dual mode of constant-current source chip.Because the merit that resistance-capacitance depressurization causes is because of too low, in greater than the application of certain wattage, rejected by a lot of units, therefore the regional developments such as the U.S., Europe, Taiwan and Korea S according to the height of input voltage or electric current and with driven LED stage by stage progressively conducting and the technology that progressively disconnects, can provide at lower cost high merit because of high efficiency LED driving power, but there are two very large problems in this technology, the firstth, the LED at each power supply string ON time weak point in period of wave in the fluorescent tube is just darker, produces obvious dark space in fluorescent tube; The secondth,, segmentation conducting method only has the LED of small part light when low pressure, has caused the dark space on the time domain, although so the segmentation conducting solved efficient and merit because of problem, effectively do not solve LED stroboscopic problem.
Summary of the invention
The utility model is intended to solve the technical problem of the upper stroboscopic in dark space and time in the space that the LED drive unit brings in the prior art, and a kind of LED drive unit is provided, and solves dark space, space and time domain stroboscopic problem in LED light fixture, especially the LED fluorescent tube.
In embodiment of the utility model, the LED drive unit that dynamically changes series parallel structure with input voltage is used for the driving LED matrix, described LED drive unit comprises an input voltage sensing module, a circuit series parallel structure control module, switch combination and the constant-current source that can change the total current size that can change the series parallel structure of LED in the LED matrix;
Described input voltage sensing module compares the critical value of input voltage from the different voltage ranges of presetting, and arrives described circuit series parallel structure control module according to input voltage status signal of comparative result output;
Described circuit series parallel structure control module, according to control signal corresponding to input voltage status signal output to described switch combination and the constant-current source that can change the total current size;
Described switch combination is connected to described constant-current source and the driven LED matrix that changes the total current size, change the series parallel structure of switch combination according to described different control signal, the described constant-current source that changes the total current size is diverted in driven LED matrix according to the series parallel structure of switch combination;
The described constant-current source that changes the total current size, the total current size that changes this constant-current source according to described different control signal cooperates described switch combination so that the electric current on unitary series of operations LED path remains on a continuous current scope.
Further, when described input voltage sensing module detected input voltage and is positioned at the minimum voltage scope, described circuit series parallel structure control module control switch matrix system drove LED all in driven LED matrix in the mode of multichannel parallel connection;
When described input voltage sensing module detected input voltage and is positioned at the ceiling voltage scope, described circuit series parallel structure control module control switch combination drove the mode of LED all in driven LED matrix multichannel series connection in parallel and with minimum road;
Wherein, under the control of described circuit series parallel structure control module, the number in parallel of LED reduces with the rising of input voltage in described driven LED matrix.
Further, the total current size of the described constant-current source that changes the total current size variation that when changing, is directly proportional with the number in parallel of LED in driven LED matrix.
Further, described circuit series parallel structure control module is controlled described switch combination under different LED series parallel structures so that all together conducting or shutoffs of the LED in described driven LED matrix, when conducting, the total current that the described constant-current source that changes the total current size provides is diverted in LED all in the described driven LED matrix path in parallel via described switch combination.
Further, described switch combination has two kinds of series parallel structures, and described predeterminated voltage scope is a low pressure range and a high pressure range;
When the input voltage sensing module detected input voltage and is positioned at low pressure range, described circuit series parallel structure control module control switch was combined in the first series parallel structure;
When the input voltage sensing module detected input voltage and is positioned at high pressure range, described circuit series parallel structure control module control switch was combined in the second series parallel structure;
Wherein, the number in parallel of driven LED is the twice of the number in parallel of driven LED in described the second series parallel structure in described the first series parallel structure.
For so that LED drive unit of the present utility model has higher power-efficient, further, described switch matrix has three kinds of series parallel structures, and described predeterminated voltage scope is pressure scope and high pressure range in the low pressure range;
When the input voltage sensing module detected input voltage and is positioned at low pressure range, described circuit series parallel structure control module control switch was combined in the first series parallel structure;
When the input voltage sensing module detected input voltage and is arranged in the pressure scope, described circuit series parallel structure control module control switch was combined in the second series parallel structure;
When the input voltage sensing module detected input voltage and is positioned at high pressure range, described circuit series parallel structure control module control switch was combined in the third series parallel structure;
Wherein, the number in parallel of driven LED is three times of number in parallel of driven LED in described the third series parallel structure in described the first series parallel structure, and the number in parallel of driven LED is the twice of the number in parallel of driven LED in described the third series parallel structure in described the second series parallel structure.
Further, the LED in the described LED matrix has three kinds of series parallel structures, and described predeterminated voltage scope is pressure scope and high pressure range in the low pressure range;
When the input voltage sensing module detected input voltage and is positioned at low pressure range, described circuit series parallel structure control module control switch was combined in the first series parallel structure;
When the input voltage sensing module detected input voltage and is arranged in the pressure scope, described circuit series parallel structure control module control switch was combined in the second series parallel structure;
When the input voltage sensing module detected input voltage and is positioned at high pressure range, described circuit series parallel structure control module control switch was combined in the third series parallel structure;
Wherein, the number in parallel of different from forenamed three kinds of structures is driven LED in described the first series parallel structure is three times of number in parallel of driven LED in described the third series parallel structure, and the number in parallel of driven LED is the twice of the number in parallel of driven LED in described the second series parallel structure in described the first series parallel structure.
Further, described input voltage sensing module, switch combination, the constant-current source that can change the total current size and circuit series parallel structure control module all are integrated on the same chip, and described driven LED arranged in matrix is in chip exterior; Described chip also is provided with to connect the interface of outer member, according to the size of current on the single LED series circuit in the driven LED matrix of the capable setting parameter of described outer member, and the critical value of adjusting described different voltage ranges.
The above technical scheme, by the critical value of input voltage from the different voltage ranges of presetting compared, and change the series parallel structure of LED in the driven LED matrix according to control signal corresponding to comparative result output, and so that the electric current on unitary series of operations LED path remains on a continuous current scope, realized that all LED are in the together conducting or extinguish in period of wave of each power supply string, efficiently solving LED in the fluorescent tube has the phenomenon of dark space, clear zone in the space, also so that significantly shorten the dark space on the time shaft, further reduced the stroboscopic problem of conventional ADS driving LED light fixture when dc low-voltage.
Description of drawings
Fig. 1 is the LED driving device structure schematic diagram of the utility model the first embodiment;
Fig. 2 is the current distributing path schematic diagram under arranging of the LED matrix of the utility model the first embodiment and gate-controlled switch and the different series parallel structure;
Fig. 3 is the current distributing path schematic diagram under arranging of the LED matrix of the utility model the second embodiment and gate-controlled switch and the different series parallel structure;
Fig. 4 is the current distributing path schematic diagram under arranging of the LED matrix of third embodiment of the invention and gate-controlled switch and the different series parallel structure.
Embodiment
Clearer for technical problem, technical scheme and beneficial effect that the utility model is solved, 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.
According to shown in Figure 1, the utility model provides a kind of LED drive unit that dynamically changes series parallel structure with input voltage, described LED drive unit is used for driving LED matrix 40, described LED drive unit comprises an input voltage sensing module 10, a circuit series parallel structure control module 20, capable of dynamic changes the constant-current source 30 of total current size, and capable of dynamic changes the switch combination 50 of the series parallel structure of LED in the LED matrix 40;
Described LED matrix 40 has high-pressure side and low-pressure end, but the high-pressure side of LED matrix 40 and low-pressure end and between form the multiple branch road with different LED series parallel structure of conducting work, for example, all LED in the described LED matrix 40 can mutually connect and form a single tandem paths, or the path that all LED in the LED matrix 40 can all LED parallel forms of formation parallel with one another;
Described input voltage sensing module 10, the input voltage that is used for the monitoring power supply, and input voltage compared from the critical value of default different voltage ranges, and according to input voltage status signal of comparative result output to described circuit series parallel structure control module 20.The critical value of default different voltage ranges described here can set in advance according to the input voltage of power supply, such as, be arranged to the high pressure range of low pressure range and the 110Vac ~ 220Vac of 0 ~ 110Vac; If will make light fixture for American market, the critical value of LED number and voltage range will be changed so into the numerical value of the input voltage range of the 110Vac that can adapt to the U.S..
Described circuit series parallel structure control module 20 is used for receiving described input voltage status signal, and according to control signal corresponding to described input voltage status signal output to described switch combination 50 and the constant-current source 30 that can change the total current size;
Described switch combination 50, be connected to constant-current source 30 and driven LED matrix 40 that can change the total current size, switch combination 50 dynamically changes series parallel structure according to described different control signal, again that each tandem paths is in parallel after allowing part LED in driven LED matrix 40 connect first, concrete series connection number and number in parallel can set in advance according to country variant supply voltage standard the configuration of driven LED matrix and control signal, when being integrated into circuit in the chip, can reserving and set the critical value that interface is adjusted voltage range.
The forward conducting voltage that electric current on the unitary series of operations path multiply by total LED number and LED is total wattage of LED matrix approximately just, neutralization keeps stable brightness in time in the space in order to make every LEDs, will keep the constant current state of fixing to the drive current of each LEDs, namely constant-current source 30 dynamically changes its total current size according to control signal corresponding to different voltage ranges together in company with switch combination 50, so that the electric current on unitary series of operations LED path keeps fixing, because driven LED connects first again each tandem paths to be carried out parallel connection behind the bunchiness, the variation that can be directly proportional with way in parallel of the described total current value that changes the constant-current source 30 of total current size, but the proportionate relationship that is difficult to when making hardware guarantee to change is with theoretical just the same, therefore as long as it is all right to allow electric current on unitary series of operations LED path remain in a certain continuous current scope, the hot spot that cause the less then bright dark space of this scope and the flicker in the time domain are just less.
Further, when described input voltage sensing module 10 monitors input voltage and is positioned at lower predeterminated voltage scope, the described input voltage status signal of output drives the work of namely switching on LED all in driven LED matrix 40 for described circuit series parallel structure control module control switch combination 50 in the mode than the multichannel parallel connection; When described input voltage sensing module 10 detects input voltage when being positioned at higher predeterminated voltage scope, the described input voltage status signal of output drives LED all in driven LED matrix for described circuit series parallel structure control module control switch combination 50 in the mode of less road parallel connection; When described input voltage sensing module detected input voltage and is positioned at the minimum voltage scope, described circuit series parallel structure control module control switch combination 50 drove LED all in driven LED matrix in the mode of multichannel parallel connection; When described input voltage sensing module detected input voltage and is positioned at the ceiling voltage scope, described circuit series parallel structure control module control switch combination 50 drove the mode of LED all in driven LED matrix 40 multichannel series connection in parallel and with minimum road; Wherein, under the control of described circuit series parallel structure control module, the number in parallel of LED reduces with the rising of input voltage in described driven LED matrix 40.
In the above technical scheme, for the electric current on the series LED path single in LED matrix 40 is remained in a certain continuous current scope, the number in parallel of LED variations that the be directly proportional when series parallel structure of total current size all LED in LED matrix 40 of the described constant-current source that changes the total current size changes and in the LED matrix 40, so so that the current value that electric current is diverted to by described switch combination 50 in the single LED tandem paths of each parallel connection can maintain in the fixing scope.The simultaneously described switch combination of described circuit series parallel structure control module 20 controls under different LED series parallel structures so that all together conducting or shutoffs of the LED in the described LED matrix 40, when conducting, the total current that the described constant-current source that changes the total current size provides is diverted in LED all in described driven LED matrix 40 path in parallel via described switch combination.
A nearlyer step ground, described input voltage sensing module 10, switch combination 50, the constant-current source 30 that can change the total current size and circuit series parallel structure control module 20 can be integrated on the same chip, and described driven LED matrix 40 is arranged on chip exterior; Described chip also is provided with to connect outer member and gets interface, according to the parameter of described outer member, can set size of current on the single LED series circuit and the critical value of adjusting described different voltage ranges by described interface.
For instance, can utilize a non-essential resistance to adjust electric current on the single LED tandem paths, adjust the critical value of different voltage ranges with other resistance.With Chinese supply voltage for example, if the LED light fixture is excessively dark when being afraid of the unusual step-down of supply voltage, not necessarily fully proportional the cutting apart of input supply voltage scope of standard, can reduce the LED number on the tandem paths, and all voltage range critical values reduce together when adjusting critical value so; If but lie in very much the power-efficient of normal input supply voltage scope, do not mind the unusual step-down of supply voltage, so just can increase the number of LED and heighten the critical value of each voltage range.
The below will be further detailed LED drive unit and the operation principle thereof with input voltage change series parallel structure of the present invention by embodiment.
The first embodiment:
In conjunction with shown in Figure 2, described LED matrix 40 is provided with two LED strings between its high-pressure side and low-pressure end, suppose that this is the circuit of doing for city's electrical specification of China, at present the forward conducting voltage of the white light LEDs of industry is 3.0V to about the 3.6V, so LED string 53 and 57 each the naturally 39 LEDs series connection of LED string, it is series connection 78 LEDs altogether that two string LED add up, so forward conducting voltage at 234Vdc to about the 302Vdc, 220Vac is through the nearly 310Vdc of heap that passes a bridge, can directly promote this 78 LEDs, and there is enough voltage to stablize the constant-current source electric current, if worry that AC supply voltage is unstable, LED is bright not during AC supply voltage peak value step-down, the unitary series of operations number can be reduced to 36 ~ 38 by 39 series connection so, and the brightness meeting becomes stable, but the pressure drop meeting of electric current on constant-current source increases, this pressure drop is not luminous on LED, but generates heat on constant-current source, has therefore reduced power-efficient.Two LED string of giving an example among Fig. 2 is serially connected with respectively 39 LEDs, during general supply voltage peak reduction the brightness meeting slightly dimmed, but can't extinguish fully.
Simultaneously, suppose that described predeterminated voltage scope is a low pressure range and a high pressure range, when power input voltage drops on low pressure range, the input voltage status signal of described input voltage sensing module 10 outputs gives LED all in the described LED matrix 40 of described circuit series parallel structure control module 20 controls with more way conducting in parallel, be among Fig. 2, LED in the described circuit series parallel structure control module 20 control LED matrixes 40 drives in the mode of two-way parallel connection, gate-controlled switch 55 is off-state, gate-controlled switch 52,54,56 and 58 is closure state, first LED branch current in the two-way parallel connection is with single-point line expression, by the high-pressure side gate-controlled switch 52 of flowing through, LED string 53 and gate-controlled switch 54 are to low-pressure end, second LED branch current in the two-way parallel connection be also with single-point line expression, by the high-pressure side gate-controlled switch 56 of flowing through, LED string 57 and gate-controlled switch 58 are to low-pressure end.
When power input voltage drops on high pressure range, the input voltage status signal of described input voltage sensing module 10 outputs gives LED all in the described LED matrix 40 of described circuit series parallel structure control module 20 controls with less way conducting in parallel, be among Fig. 2, LED in the described circuit series parallel structure control module 20 control LED matrixes 40 drives in the mode of one tunnel parallel connection, at this moment, gate-controlled switch 55 becomes closure state, gate-controlled switch 54 and 56 becomes open-circuit condition, electric current in this LED branch road is represented by dotted lines, by the high-pressure side gate-controlled switch 52 of flowing through, LED string 53, gate-controlled switch 55, LED string 57 and gate-controlled switch 58 are to low-pressure end, wherein gate-controlled switch 52 and gate-controlled switch 58 are the state of always conducting, configuration shares if this drive circuit does not need can change with other multi-segment voltage scope frameworks, switch 52 and switch 58 do not need to make gate-controlled switch so, it is all right directly to make guiding path, although therefore in Fig. 2, indicated numeral, but directly be drawn as the guiding path of closure state, can save cost.
In the above control procedure, no matter form what kind of LED branch road path between the high-pressure side of LED matrix 40 and the low-pressure end, the operating current that current source 30 offers each LED string is identical, in other words, the variation that is directly proportional with the way in parallel that LED goes here and there of the size of the total current of described current source output, therefore total output current of current source is the twice of total output current during in 53 and 57 series connection of LED string when LED string 53 and LED string 57 are parallel connection, when producing light fixture, will LED go here and there 53 and LED string 57 match, allow both forward conducting voltage is consistent as far as possible, this operation can so that current source when two LED connection in series-parallel work, shunting is consistent to the electric current of each LED branch road, current balance type when the adding series resistance can be strengthened parallel connection in LED string 53 and 57, but this series resistance will reduce power-efficient, if constant-current source is splitted into two parts, in LED string 53 and 57, respectively put a constant-current source, still meet above-mentioned patent working method, but can increase cost, and can reduce power-efficient when causing in that constant-current source is not of uniform size when series connection.
The second embodiment:
Fig. 3 is the current distributing path under arrange schematic diagram and the different series parallel structures of the LED matrix of the utility model the second embodiment and gate-controlled switch; In conjunction with shown in Figure 3, Fig. 3 is the example that can form three kinds of LED connection in series-parallel combinations in the LED matrix 40, the predeterminated voltage scope is divided into three sections voltage ranges, respectively low pressure range, middle pressure scope and high pressure range, embodiment compares with the first, present embodiment can reduce power loss that the voltage on the constant-current source 30 causes to improve the overall efficiency of circuit, can also shorten temporal dark space at lower input supply voltage shorting advance LED.In described LED matrix 40, series-parallel switch combination and six LED strings are arranged between high-pressure side and the low-pressure end, we are still to give an example in implementation of China, suppose that each LED string is serially connected with respectively 13 LEDs, a LED string is 13 LEDs, two LED strings are 26 LEDs, three LED go here and there 39, by that analogy, the longest LED string is that LED series connection sum is 78 when the situation of six string LED strings in the series connection of single road, if worry that supply voltage is unstable, LED is bright not during AC supply voltage peak value step-down, the LED series connection number of each LED string can be reduced to 12 by 13 series connection so, and the brightness meeting is more relatively stable.
When the input supply voltage that detects when input voltage sensing module 10 is positioned at low pressure range, the output-input voltage status signal gives described circuit series parallel structure control module 20 control switchs combination 50 with the mode conducting of LED all in the described LED matrix 40 with three tunnel parallel connections, i.e. gate-controlled switch 640 in Fig. 3,650,654 and 660 is off-state, gate-controlled switch 610,612,620,652,622,630 and 632 is closure state, first LED branch current in three road parallel connection LEDs is represented by dotted lines, by the high-pressure side gate-controlled switch 610 of flowing through, two LED strings are connected in series 26 LEDs that form and arrive low-pressure end through gate-controlled switch 612 again; Second LED branch current in three tunnel parallel connections also is represented by dotted lines, by high-pressure side through gate-controlled switch 620 13 LEDs that LED string forms of flowing through, through gate-controlled switch 652,13 LEDs that form through another LED string again arrive low-pressure end through gate-controlled switch 622 more again; The 3rd LED branch current in three tunnel parallel connections also is represented by dotted lines, by high-pressure side 26 LEDs that gate-controlled switch 630, two LED string serial connection form of flowing through, again through gate-controlled switch 632 to low-pressure end.
When the input supply voltage that detects when input voltage sensing module 10 is arranged in the pressure scope, the output-input voltage status signal gives described circuit series parallel structure control module 20 control switchs combination 50 with the mode conducting of LED all in the described LED matrix 40 with the two-way parallel connection, it is controlled switch 612,620,622,630 and 652 is off-state, gate-controlled switch 610,650,660,640,654 and 632 is closure state, first LED branch current in the two-way parallel connection is with single-point line expression, by high-pressure side flow through gate-controlled switch 610 then through 26 LEDs again through gate-controlled switch 650, through 13 LEDs, arrive low-pressure end finally by gate-controlled switch 660 again; Second LED branch current in the two-way parallel connection be also with single-point line expression, by high-pressure side flow through gate-controlled switch 640 then through 13 LEDs again through gate-controlled switch 654, again through 26 LEDs, finally by gate-controlled switch 632 to low-pressure end.
When the input supply voltage that detects when input voltage sensing module 10 is positioned at high pressure range, the output-input voltage status signal gives described circuit series parallel structure control module 20 control switchs combination 50 with the mode conducting of LED all in the described LED matrix 40 with one tunnel parallel connection, gate-controlled switch 612,620,640,630,660 and 622 is off-state, gate-controlled switch 610,650,652,654 and 632 is closure state, the electric current of all LED of single channel conducting represents with double dot dash line, by high-pressure side flow through gate-controlled switch 610 then through 26 LEDs again through gate-controlled switch 650, again through 13 LEDs, again through gate-controlled switch 652 then through 13 LEDs again through gate-controlled switch 654, through 26 LEDs, arrive low voltage rail finally by gate-controlled switch 632 again.
In above-described three kinds of series parallel structure modes, no matter which kind of series parallel structure mode, described circuit series parallel structure control module 20 is all controlled constant-current source 30 provides same size to the single LED string in the described LED matrix 40 operating current, therefore, in the present embodiment, the variation that also is directly proportional with the way in parallel of LED string of the total current size of constant-current source 30 output, when the total current of the constant-current source 30 when in parallel in three paths of LEDs string paths is a paths of LEDs connection in series-parallel three times, twice when the total current of the constant-current source 30 when in parallel in two paths of LED string path is paths of LEDs string path parallel connection, so no matter be that several roads are in parallel, the electric current in the single LED string all is to maintain an identical definite value.
The third embodiment:
Fig. 4 is the current distributing path under arrange schematic diagram and the different series parallel structures of the LED matrix of the third embodiment of the utility model and gate-controlled switch; In conjunction with shown in Figure 4, Fig. 4 is the example that can form three kinds of LED series parallel structure combinations in the another kind of LED matrix 40, the series LED number of three of the second embodiment kinds of structures is respectively 26 among Fig. 3,39 and 78, corresponding conducting voltage ratio is 2:3:6, therefore the low pressure conducting is interval, middle pressure conducting is interval, the voltage range ratio in high pressure conducting interval roughly is 2:(3-2): (6-3)=2:1:3, although so design is more excellent than the first embodiment, but so that constant-current source 30 is at the different height of efficient meeting of different voltage ranges, for further optimization efficiency, take new series connection number ratio, the number of three kinds of series connection is respectively 26,52 and 78, so, the ratio of three sections voltage ranges has been exactly 1:1:1, and constant-current source 30 is equally high in the efficient of each voltage range, can promote whole power-efficient.
Series-parallel switch combination and six LED strings are arranged between the high-pressure side of LED matrix 40 and the low-pressure end among Fig. 4, we suppose that each LED string is serially connected with respectively 26 LEDs, a string have 26, and two strings have 52, and three strings just have 78, and previous embodiments, if it is unstable that supply voltage is worried in puzzlement, LED is bright not when the maximum mains voltage step-down, and the number of single-string LED can being connected so reduces to 25 or 24 series connection by 26 series connection, the brightness meeting is stable, but can lose efficient.
Predeterminated voltage scope among Fig. 4 embodiment also is divided into three sections voltage ranges, is respectively low pressure range, middle pressure scope and high pressure range.When the input supply voltage that detects when input voltage sensing module 10 is positioned at low pressure range, the output-input voltage status signal is given the mode conducting of LED all in the described LED matrix 40 of described circuit series parallel structure control module 20 controls with six tunnel parallel connections, controlling corresponding gate-controlled switch makes the electric current in the LED matrix 40 mobile by the direction of dotted line, first LED branch current gone here and there and 712 flow to low-pressure end through a gate-controlled switch again after in parallel by high-pressure side 700 LED that flows through with second LED branch current first through a gate-controlled switch again by the high-pressure side 700 LED string 710 of flowing through, in like manner the 3rd LED branch current gone here and there and 722 flow to low-pressure end through a gate-controlled switch again after in parallel by high-pressure side 700 LED that flows through with the 4th LED branch current first through a gate-controlled switch again by the high-pressure side 700 LED string 720 of flowing through, in like manner the 5th LED branch current gone here and there and 732 flow to low-pressure end through a gate-controlled switch again after in parallel by high-pressure side 700 LED that flows through with the 6th LED branch current first through a gate-controlled switch again by the high-pressure side 700 LED string 730 of flowing through, because identical in the control principle of gate-controlled switch and the previous embodiment, just gate-controlled switch is closed different from the combination that disconnects, so the control details to gate-controlled switch is not described in detail in the present embodiment.
When the input supply voltage that detects when input voltage sensing module 10 is arranged in the pressure scope, the output-input voltage status signal is given the mode conducting of LED all in the described LED matrix 40 of described circuit series parallel structure control module 20 controls with three tunnel parallel connections, under this kind control mode, the corresponding gate-controlled switch of circuit series parallel structure control module 20 controls makes the electric current in the LED matrix 40 flow by single dashdotted direction, first LED branch current flowed through LED string 710 and LED string 720 tandem pathss that form to low-pressure end by high-pressure side, second LED branch current flowed through LED string 712 and LED string 730 tandem pathss that form to low-pressure end by high-pressure side, and the 3rd LED branch current gone here and there 732 tandem pathss that form to low-pressure end by flow through LED string 722 and LED of high-pressure side.
When the input supply voltage that detects when input voltage sensing module 10 is positioned at high pressure range, the output-input voltage status signal is given the mode conducting of LED all in the described LED matrix 40 of described circuit series parallel structure control module 20 controls with the two-way parallel connection, under this kind control mode, the corresponding gate-controlled switch of circuit series parallel structure control mould 20 controls makes the electric current in the LED matrix 40 mobile by the direction of double dot dash line, first LED branch current is by the high-pressure side LED string 710 of flowing through, LED string 720, flow to low-pressure end behind the path that 730 series connection of LED string form, second LED branch current is by the high-pressure side LED string 712 of flowing through, LED string 722, flow to low-pressure end behind the path that 732 series connection of LED string form.
In above-described three kinds of control modes, no matter which kind of control mode, described control module 20 is all controlled current source 30 and is provided same operating current to the string of the LED in the described LED matrix 40, therefore, in the present embodiment, the variation that also is directly proportional with the way in parallel of LED string of the total current size of current source 30 output, when therefore the total current of current source is the two paths of LED connection in series-parallel when six paths of LEDs connection in series-parallel three times, twice when the current source total current when six paths of LEDs connection in series-parallel is three paths of LEDs connection in series-parallel, so no matter be that several roads are in parallel, electric current in the single LED string all is to maintain definite value, and voltage range all is take 26 LEDs as a scope, therefore obtains best balanced constant-current source efficient, and then obtains better whole power-efficient, but the number of gate-controlled switch has been Duoed some than the second embodiment, has increased some costs.
Above-described the second embodiment and the third embodiment, embodiment compares with the first, is divided into three sections voltage ranges and can improves power-efficient and power factor, and increasing number of switches can improve hardware cost; When the mode of voltage range two-part can't reach the power-efficient of customer demand and power factor, it is the mode of 3:2:1 that the meeting of intuition develops top the first number in parallel, the roughly direct ratio of number but the upper limit of each supply voltage scope is connected with LED in this scope, be 2:3:6, first paragraph scope namely: second segment scope: the 3rd segment limit=2:(3-2): (6-3)=2:1:3, the distribution of this supply voltage scope is also inhomogeneous, therefore be ready to spend more slightly again under the prerequisite of some costs, just can adopt the mode that number ratio in parallel is 6:3:2 in three scopes of the second, the series connection number ratio of its correspondence is 2:4:6, first paragraph scope namely: second segment scope: the 3rd segment limit=2:(4-2): (6-4)=2:2:2, the distributing very evenly of this supply voltage scope.
The switch cost of paying above-mentioned increase obtains uniform voltage range, can reduce maximum pressure drop and total heating above the constant-current source, and provide higher merit because of and higher power-efficient.
The led drive circuit that above embodiment of the present utility model provides, can certain more than the specific wattage (for example 5 watts) realize that large merit is because of the usefulness of (for example merit because of greater than 0.8), the efficient of this LED driving power effectively improves simultaneously, and all LED are in the together conducting or extinguish together in period of wave of each power supply string, in fluorescent tube, do not have the difference of dark space, clear zone, solve high merit because of, the problem of high efficiency led drive circuit, and since when low pressure all LED be conducting together, so that the dark space on the time shaft significantly shortens, further reduced conventional ADS driving causes the LED light fixture when dc low-voltage stroboscopic problem.
Claims (8)
1. LED drive unit that changes series parallel structure with input voltage, described LED drive unit is used for the driving LED matrix, it is characterized in that: described LED drive unit comprises an input voltage sensing module, a circuit series parallel structure control module, switch combination and the constant-current source that can change the total current size that can change the series parallel structure of LED in the LED matrix;
Described input voltage sensing module compares the critical value of input voltage from the different voltage ranges of presetting, and arrives described circuit series parallel structure control module according to input voltage status signal of comparative result output;
Described circuit series parallel structure control module, according to control signal corresponding to input voltage status signal output to described switch combination and the constant-current source that can change the total current size;
Described switch combination is connected to described constant-current source and the driven LED matrix that changes the total current size, change the series parallel structure of switch combination according to described different control signal, the described constant-current source that changes the total current size is diverted in driven LED matrix according to the series parallel structure of switch combination;
The described constant-current source that changes the total current size, the total current size that changes this constant-current source according to described different control signal cooperates described switch combination so that the electric current on unitary series of operations LED path remains on a continuous current scope.
2. LED drive unit as claimed in claim 1 is characterized in that:
When described input voltage sensing module detected input voltage and is positioned at the minimum voltage scope, described circuit series parallel structure control module was controlled described switch combination LED all in driven LED matrix is driven in the mode of multichannel parallel connection;
When described input voltage sensing module detected input voltage and is positioned at the ceiling voltage scope, described circuit series parallel structure control module was controlled described switch combination the mode of LED all in driven LED matrix multichannel series connection in parallel and with minimum road is driven;
Wherein, under the control of described circuit series parallel structure control module, the number in parallel of described switch combination reduces with the rising of input voltage.
3. LED drive unit as claimed in claim 2 is characterized in that: the variation that is directly proportional with the number in parallel of LED in driven LED matrix when changing of the total current size of the described constant-current source that changes the total current size.
4. LED drive unit as claimed in claim 3, it is characterized in that: described circuit series parallel structure control module is controlled described switch combination under different LED series parallel structures so that all together conducting or shutoffs of the LED in described driven LED matrix, when conducting, the total current that the described constant-current source that changes the total current size provides is diverted in LED all in the described LED matrix path in parallel via described switch combination.
5. LED drive unit as claimed in claim 4, it is characterized in that: described switch combination has two kinds of series parallel structures, and described predeterminated voltage scope is a low pressure range and a high pressure range;
When the input voltage sensing module detected input voltage and is positioned at low pressure range, described circuit series parallel structure control module control switch was combined in the first series parallel structure;
When the input voltage sensing module detected input voltage and is positioned at high pressure range, described circuit series parallel structure control module control switch was combined in the second series parallel structure;
Wherein, the number in parallel of driven LED is the twice of the number in parallel of driven LED in described the second series parallel structure in described the first series parallel structure.
6. LED drive unit as claimed in claim 4, it is characterized in that: described switch matrix has three kinds of series parallel structures, and described predeterminated voltage scope is pressure scope and high pressure range in the low pressure range;
When the input voltage sensing module detected input voltage and is positioned at low pressure range, described circuit series parallel structure control module control switch was combined in the first series parallel structure;
When the input voltage sensing module detected input voltage and is arranged in the pressure scope, described circuit series parallel structure control module control switch was combined in the second series parallel structure;
When the input voltage sensing module detected input voltage and is positioned at high pressure range, described circuit series parallel structure control module control switch was combined in the third series parallel structure;
Wherein, the number in parallel of driven LED is three times of number in parallel of driven LED in described the third series parallel structure in described the first series parallel structure, and the number in parallel of driven LED is the twice of the number in parallel of driven LED in described the third series parallel structure in described the second series parallel structure.
7. LED drive unit as claimed in claim 4, it is characterized in that: the LED in the described LED matrix has three kinds of series parallel structures, and described predeterminated voltage scope is pressure scope and high pressure range in the low pressure range;
When the input voltage sensing module detected input voltage and is positioned at low pressure range, described circuit series parallel structure control module control switch was combined in the first series parallel structure;
When the input voltage sensing module detected input voltage and is arranged in the pressure scope, described circuit series parallel structure control module control switch was combined in the second series parallel structure;
When the input voltage sensing module detected input voltage and is positioned at high pressure range, described circuit series parallel structure control module control switch was combined in the third series parallel structure;
Wherein, the number in parallel of driven LED is three times of number in parallel of driven LED in described the third series parallel structure in described the first series parallel structure, and the number in parallel of driven LED is the twice of the number in parallel of driven LED in described the second series parallel structure in described the first series parallel structure.
8. such as the described LED drive unit of claim 1-7 any one, it is characterized in that: described input voltage sensing module, switch combination, the constant-current source that can change the total current size and circuit series parallel structure control module all are integrated on the same chip, and described driven LED arranged in matrix is in chip exterior; Described chip also is provided with to connect the interface of outer member, according to the size of current on the single LED series circuit in the driven LED matrix of the setting parameter of described outer member, and the critical value of adjusting described different voltage ranges.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320157246 CN203251462U (en) | 2013-04-01 | 2013-04-01 | LED drive device capable of changing series-parallel composition along input voltage |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320157246 CN203251462U (en) | 2013-04-01 | 2013-04-01 | LED drive device capable of changing series-parallel composition along input voltage |
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| CN203251462U true CN203251462U (en) | 2013-10-23 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103167701A (en) * | 2013-04-01 | 2013-06-19 | 黄世蔚 | Light emitting diode (LED) driving device for changing series-parallel structure along with input voltage and working method |
| CN104080250A (en) * | 2014-06-27 | 2014-10-01 | 深圳市明微电子股份有限公司 | Stroboscopic-free LED lighting circuit and device |
-
2013
- 2013-04-01 CN CN 201320157246 patent/CN203251462U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103167701A (en) * | 2013-04-01 | 2013-06-19 | 黄世蔚 | Light emitting diode (LED) driving device for changing series-parallel structure along with input voltage and working method |
| CN103167701B (en) * | 2013-04-01 | 2015-09-16 | 黄世蔚 | LED drive device and the method for work of series parallel structure is changed with input voltage |
| CN104080250A (en) * | 2014-06-27 | 2014-10-01 | 深圳市明微电子股份有限公司 | Stroboscopic-free LED lighting circuit and device |
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