CN201976304U - Multichannel light emitting diode driving system - Google Patents
Multichannel light emitting diode driving system Download PDFInfo
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- CN201976304U CN201976304U CN2011201358928U CN201120135892U CN201976304U CN 201976304 U CN201976304 U CN 201976304U CN 2011201358928 U CN2011201358928 U CN 2011201358928U CN 201120135892 U CN201120135892 U CN 201120135892U CN 201976304 U CN201976304 U CN 201976304U
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Abstract
The utility model discloses a multichannel light emitting diode driving system which comprises a power converter, a rectification and filter unit, a plurality of serial light emitting diodes, a plurality of linear regulators, a constant current/constant voltage controller, an optically coupled isolator and a pulse-width modulation (PWM) controller, wherein the constant current/constant voltage controller detects current conducted on the serial light emitting diodes in the multichannel light emitting diode driving system and detects the output voltage value of the rectification and filter unit so as to provide voltage compensation; the linear regulators are used for regulating the current difference between the serial light emitting diodes to realize even flow control; and the light emitting diodes light with stable luminance.
Description
Technical field
The utility model relates to a kind of LED drive system, relates in particular to a kind of multichannel LED drive system.
Background technology
Light-emitting diode (light emitting diode, LED) having high-luminous-efficiency, long service life, operating temperature range extensively reaches environmental protection and does not have characteristics such as mercury, make it surmount incandescent lamp and fluorescent lamp bulb, and leader's lighting field enter the New Times of a solid-state illumination.
But since LED itself forward voltage and electric current can influence the life-span of LED and the intensity of light source output to the relation of temperature characterisitic, therefore need to use constant current source make LED can reach optimization and can improve power-efficient in the illumination occasion.Again, multichannel circuit of LED is because of driving a plurality of light-emitting diode serials that are connected in parallel simultaneously, and wherein respectively this light-emitting diode serial is made up of a plurality of light-emitting diodes; When using a voltage source to drive this multichannel circuit of LED, may cause conducting in the electric current of different light-emitting diode serials difference to some extent because of the difference of light-emitting diode internal resistance, cause the uneven problem of luminosity to produce, and then reduce the efficient of whole multichannel LED driving circuit.
The utility model content
A purpose of the present utility model is to provide a kind of multichannel LED drive system, can reach the drive circuit of this multichannel circuit of LED of sharing control.
To achieve these goals, the utility model provides a kind of multichannel LED drive system, comprises:
One power supply changeover device;
One rectification and filter unit are electrically connected at this power supply changeover device;
A plurality of light-emitting diode serials are made up of a plurality of light-emitting diodes that are connected in series, and these a plurality of light emitting diode string behaviors are connected in parallel in this rectification and filter unit;
A plurality of linear regulators, comprise quantity a plurality of switching diodes corresponding and the quantity a plurality of metal oxide semiconductcor field effect transistors corresponding, and respectively this linear regulator is electrically connected at respectively this light-emitting diode serial respectively accordingly with described light-emitting diode serial with described light-emitting diode serial;
Certain electric current/decide voltage controller is electrically connected at this a plurality of linear regulators;
One optically coupled isolator has a luminous end and a sensitization end, and this luminous end is electrically connected at this and decides electric current/decide voltage controller, decides electric current/decide the conducting electric current of voltage controller to receive this, and is sent to this sensitization end isolator;
One PWM controller is electrically connected at this power supply changeover device and this optically coupled isolator, to receive the perceptual signal that this optically coupled isolator transmitted and to control this power supply changeover device.
Above-mentioned multichannel LED drive system wherein, also comprises a protected location, is electrically connected at this and decides electric current and decide voltage controller and this linear regulator, and this protected location comprises:
One pressurizer;
One in order to first operational amplifier of this rectification and filter unit output voltage and this stabilizer output voltage relatively, and the one negative input is electrically connected at this pressurizer; And
A plurality of protective resistors are electrically connected at a positive input and this rectification and the filter unit of this pressurizer.
Above-mentioned multichannel LED drive system, wherein, this protected location also comprises:
One second operational amplifier is electrically connected at this pressurizer;
A plurality of first switch elements are electrically connected at the drain electrode of this second operational amplifier and these a plurality of metal oxide semiconductcor field effect transistors; And
A plurality of second switch elements are electrically connected at the source electrode of this second operational amplifier and these a plurality of metal oxide semiconductcor field effect transistors.
Above-mentioned multichannel LED drive system, wherein, this protected location also comprises a short-circuit protection circuit, and this short-circuit protection circuit comprises:
One in order to detect the auxiliary winding of voltage that this power supply changeover device provides, and is electrically coupled to this power supply changeover device;
One protection diode is electrically connected at this auxiliary winding;
One the first transistor is electrically connected at this protection diode;
One transistor seconds is electrically connected at this protection diode and this first transistor; And
One the 3rd transistor is electrically connected at this protection diode.
Above-mentioned multichannel LED drive system, wherein, this first transistor is a positive-negative-positive two-carrier junction transistor, this transistor seconds is a NPN type two-carrier junction transistor.
Above-mentioned multichannel LED drive system, wherein, this power supply changeover device is an isolated DC/DC transducer.
Above-mentioned multichannel LED drive system, wherein, this is decided electric current/decide voltage controller and comprises the resistance-capacitance network that a pressurizer and is electrically connected at this pressurizer.
Above-mentioned multichannel LED drive system, wherein, this resistance-capacitance network comprises a resistor and a capacitor and decides electric current/the decide frequency response of voltage controller to determine this.
Above-mentioned multichannel LED drive system also comprises a PWM dim signal, be electrically connected on this linear regulator with should decide electric current/decide voltage controller.
Effect of the present utility model is, utilize this to decide electric current/decide voltage controller and detect conducting in the electric current of these a plurality of light-emitting diode serials, and the output voltage values of this rectification and filter unit, so that being provided, this power supply changeover device does the compensation of voltage, and by these a plurality of linear regulators to adjust these a plurality of light emitting diode string current difference in the ranks, to reach sharing control.
The utility model is decided electric current/decide voltage controller 50 by this and is detected conductings in the electric current of these a plurality of light-emitting diode serials 30, reaches the output voltage values of this rectification and filter unit, to control the compensation that this electric pressure converter reaches voltage; And, these a plurality of linear regulators 40 are fine to adjust the current difference of conducting in 30 of this light-emitting diode serials, make these a plurality of light-emitting diode serials 30 be able to the electric current that conducting equates and reach sharing control, cause luminous with light stable intensity of these a plurality of light-emitting diodes.
Below in conjunction with the drawings and specific embodiments the utility model is described in detail, but not as to qualification of the present utility model.
Description of drawings
Fig. 1 is the circuit block diagram of multichannel LED drive system of the present utility model;
Fig. 2 is electric current/the decide circuit diagram of voltage controller and linear controller of deciding of the present utility model;
Fig. 3 is the circuit diagram of excess voltage protection of the present utility model and circuit overcurrent protection;
Fig. 4 is the circuit diagram of short-circuit protection circuit of the present utility model.
Wherein, Reference numeral
The Cf capacitor
Dp protects diode
The Ds switching diode
The Q1 the first transistor
The Q2 transistor seconds
R1, R2, R3 voltage grading resistor
R5, R6, R7 protective resistor
The Rf resistor
The Rs sense resistor
Sw1 first switch element
Sw2 second switch element
1 multichannel LED drive system
10 power supply changeover devices
20 rectifications and filter unit
30 light-emitting diode serials
40 linear regulators
42 metal oxide semiconductcor field effect transistors
50 decide electric current/decide voltage controller
60 optically coupled isolators
62 luminous ends
The 70PWM controller
80 protected locations
82 short-circuit protection circuits
The 90PWM dim signal
Embodiment
Cooperate and consult Fig. 1, be the circuit block diagram of multichannel LED drive system of the present utility model.This multichannel LED drive system is electrically connected at the DC power supply of an outside, to multi-group light-emitting diode serial power supply, (backlight) backlight to be applied to field.This multichannel LED driving circuit 1 comprises a power supply changeover device 10, a rectification and filter unit 20, a plurality of light-emitting diode serial 30, a plurality of linear regulator (linear regulator) 40, certain electric current/decide voltage controller (CC/CVcontroller) 50, an optically coupled isolator 60, a PWM (pulse width modulation) controller 70 and a protected location 80.
This power supply changeover device 10 is electrically connected at this DC power supply, and in present embodiment, this power supply changeover device 10 is an isolated DC/DC transducer, and this isolated DC/DC transducer comprises a main transformer (figure does not show).This isolated DC/DC transducer carries out the adjustment of voltage potential at this DC power supply of input, and this DC power supply is the primary side input by this main transformer, and via exporting by this its secondary side after the power conversion; Its voltage potential adjustment mode comprises boosts or step-down, and makes adjusted voltage be stabilized in the magnitude of voltage that sets, for driving these a plurality of light-emitting diode serials 30.Wherein, this power supply changeover device 10 can be flyback (flyback) transducer, a forward type (forward) transducer, a push-pull type (push-pull) transducer, a semibridge system (half-bridge) transducer or a full-bridge type (full-brige) transducer.
This rectification and filter unit 20 are electrically connected to this power supply changeover device 10, with voltage commutation that will be behind buck or boost and be filtered into a direct voltage source stably, for driving these a plurality of light-emitting diode serials 30.
These a plurality of light-emitting diode serials 30 are to be electrically connected at this rectification and filter unit 20 with parallel way respectively, and respectively this light-emitting diode serial 30 is made up of a plurality of light-emitting diodes that are connected in series (figure does not show).
Cooperate and consult Fig. 2, be the circuit diagram of multichannel LED drive system of the present utility model.Respectively this linear regulator 40 is electrically connected at respectively this light-emitting diode serial 30 respectively accordingly, make and have identical conducting electric current (current-sharing) fine to adjust respectively this light-emitting diode serial 30, make these a plurality of light-emitting diode serials 30 reach the output of light stable intensity.Respectively this linear regulator 40 comprises a switching diode Ds, a metal oxide semiconductcor field effect transistor (MOSFET) 42 and a sense resistor Rs, by the control width of the conductive channel of this metal oxide semiconductcor field effect transistor 42 respectively, can control conducting effectively in the magnitude of current of this light-emitting diode serial 30 respectively.
Consult Fig. 1 and Fig. 2 again, should decide electric current/decide voltage controller 50 be electrically connected at this a plurality of light-emitting diode serials 30 and reach these a plurality of linear regulators 40, to detect conducting in the electric current of respectively this light-emitting diode serial 30 and the output voltage of this rectification and filter unit 20, the compensation of the secondary side voltage of this power supply changeover device 10 is provided, and then make respectively that this light-emitting diode serial 30 has identical conducting electric current, reach the output of light stable intensity.Should decide electric current/decide voltage controller 50 comprise a TL431 pressurizer and a resistance-capacitance network, this TL431 pressurizer is that a plurality of voltage grading resistor R1, R2, the R3 by this resistance-capacitance network obtains the driving voltage of the reference edge REF of TL431 pressurizer in the dividing potential drop mode, and then the conducting of controlling this TL431 pressurizer whether.In addition, the resistor R f of this resistance-capacitance network and capacitor Cf can determine this to decide electric current/the decide frequency response of voltage controller 50.
This optically coupled isolator 60 is electrically connected at this and decides electric current/decide voltage controller 50, and more particularly, a luminous end 62 of this optically coupled isolator 60 is electrically connected at the negative electrode (K pin) of this TL431 pressurizer.Wherein, when this TL431 pressurizer opens circuit (turn-off), be to drive this optically coupled isolator 60, so its luminous end 62 is not luminous, and a sensitization end (not shown) output one that is positioned at these optically coupled isolator 60 other ends corresponds to the perceptual signal of zero luminous intensity; And when this TL431 pressurizer conducting, produce an electric current to drive this optically coupled isolator 60, and its luminous end 62 is emitted beam, this its light of sensitization end sensing, and export the perceptual signal of a corresponding luminous intensity size.And, when the voltage by this rectification and filter unit 20 outputs becomes big gradually, the voltage of the reference edge REF of this TL431 pressurizer also increases gradually, cause conducting to increase in the electric current of this TL431 pressurizer, so the luminous intensity of the luminous end 62 of this optically coupled isolator 60 strengthens, the detected light signal strength of its sensitization end is also big more.
In addition, this a plurality of linear regulators 40 and decide electric current/decide voltage 50 to receive a PWM dim signal 90 respectively, with the conducting of the metal oxide semiconductcor field effect transistor 42 of controlling these a plurality of linear regulators 40 or close, and these a plurality of light-emitting diode serials 30 are carried out the control of light modulation.
This PWM controller 70 is electrically connected at this sensitization end of this electric pressure converter 10 and this optically coupled isolator 60, the sensitization end of this optically coupled isolator 60 is after the luminous intensity that senses this luminous end 62, provide the perceptual signal of a corresponding luminous intensity size to give this PWM controller 70, for the corresponding responsibility cycle (duty cycle) of adjusting this PWM controller 70, also i.e. switching time of this PWM controller, to increase and decrease this electric pressure converter 10 of control effectively in the changing voltage value of the secondary side of its principal voltage device, and then make the current stabilization of conducting in these a plurality of light-emitting diode serials 30, for these a plurality of light-emitting diode serial 30 uniform bright dippings.
When FEEDBACK CONTROL was carried out in these a plurality of light-emitting diode serials 30, conducting was gone up in these a plurality of sense resistor Rs that are connected to these a plurality of linear regulators 40 in the electric current of these a plurality of light-emitting diode serials 30 and is produced a sensing voltage.When conducting in the conducting current value of wherein a light-emitting diode serial 30 during less than a predetermined current value, make magnitude of voltage correspondence less of this sensing voltage; And when cross-over connection in the voltage difference at switching diode Ds two ends during greater than its conducting voltage, this switching diode Ds conducting.Side by side, should decide the reference edge REF voltage of electric current/decide this TL431 pressurizer of voltage controller 50 dragged down, and when the voltage of the reference edge REF of TL431 pressurizer during less than its preset reference voltage (2.5V), then this TL431 pressurizer is just as opening circuit, these optically coupled isolator 60 not conductings, promptly the luminous end 62 of this optically coupled isolator 60 is not luminous yet.The light signal that also do not have that the sensitization end of this optically coupled isolator 60 is relative receives, then export a perceptual signal and give this PWM controller, changing voltage with the secondary side that improves this power supply changeover device 10, make conducting in the electric current of these a plurality of light-emitting diode serials 30 along with the voltage that power supply changeover device 10 is provided rises, until conducting in the electric current of these a plurality of light-emitting diode serials 30 more than or equal to this predetermined current value, then these a plurality of switching diode Ds open circuit.
After these a plurality of switching diode Ds opened circuit, whether the bleeder circuit that this this TL431 pressurizer of deciding electric current/decide voltage controller 50 constitutes by resistor R 1, R2, R3 was too high with the magnitude of voltage that detects this power supply changeover device 10 and provided in the dividing potential drop of its K pin (negative electrode).When the voltage of K pin during greater than a predeterminated voltage value, then this TL431 pressurizer conducting, this moment, optically coupled isolator 60 was driven, and also was that luminous end 62 emits beam, and was passed to this sensitization end isolator.This sensitization end is sent the perceptual signal of a pair of luminous intensity size that should the luminous end light-emitting line to this PWM controller 70, and, avoid excessive voltage to cause the damage of these a plurality of light-emitting diode serials 30 via the output voltage of modulation with the main transformer secondary side of stablizing this power supply changeover device 10.
Because different light-emitting diode serial 30 its conducting voltage (Vf) may not all equate, therefore with conducting the light-emitting diode serial 30 of minimum current being arranged by above-mentioned drives mechanism is basis for estimation, whether increase the changing voltage value of the main transformer secondary side of this power supply changeover device 10 with decision, and then make conducting all can be equal to or greater than the predetermined current value in the electric current of other light-emitting diode serial 30.Then, respectively this metal oxide semiconductcor field effect transistor 42 of this linear regulator 40 carries out the adjustment of electric current at the conducting electric current greater than respectively this light-emitting diode serial 30 of predetermined current value.Respectively this metal oxide semiconductcor field effect transistor 42 can be adjusted its conducting width according to the difference of conducting electric current and predetermined current, so that the conducting electric current of these a plurality of light-emitting diode serials 30 all equates.The pressure drop that causes this sense resistor Rs when the conducting electric current of arbitrary light-emitting diode serial 30 is during greater than a scheduled voltage, then the magnitude of voltage at the drain electrode (drain) of Dui Ying this metal oxide semiconductcor field effect transistor 42 and source electrode (source) two ends improves, meaning promptly reduces the channel width of this metal oxide semiconductcor field effect transistor 42, make drain electrode and the resistance between source electrode (RDS) that should metal oxide semiconductcor field effect transistor 42 be improved, and make the pressure drop at this sense resistor Rs two ends descend, and then conducting is descended in the electric current of this light-emitting diode serial 30.So, make conducting equal this predetermined current value, and then it is all identical to reach the electric current of these a plurality of light-emitting diode serials 30 of conducting, and makes the luminous intensity unanimity of these a plurality of light-emitting diodes in the current value of these a plurality of light-emitting diode serials 30.
Cooperate and consult Fig. 3, be the circuit diagram of excess voltage protection of the present utility model and circuit overcurrent protection.This protected location 80 is electrically connected at this rectification and filter unit 20 and this linear regulator 40, and this protected location 80 includes one first operational amplifier U1, one second operational amplifier U2, a TL431 pressurizer, a plurality of first switch element Sw1 and a plurality of second switch element Sw2.The positive input of this first operational amplifier U1 is electrically connected at the output of this rectification and filter unit 20 by this three protective resistor R5, R6, R7; its negative input electrically connects this TL431 pressurizer, and wherein this TL431 pressurizer has a reference voltage level (2.5V).The positive input of this second operational amplifier U2 is electrically connected at the drain electrode and the source electrode of this metal oxide semiconductcor field effect transistor 42 of this linear regulator 40 respectively by these a plurality of first switch element Sw1 and this a plurality of second switch element Sw2, and its negative input is electrically connected at this TL431 pressurizer.
When the partial pressure value of these a plurality of protective resistor R5, R6, R7 during greater than this reference voltage level; this first operational amplifier U1 sends a guard signal; to close voltage source; cause these a plurality of light-emitting diode serials 30 to stop action; so with reach overvoltage protection (over voltage protection, OVP) and the effect of light-emitting diode open-circuit-protection.Also promptly this first operational amplifier U1 is by this rectification relatively and the voltage of filter unit 20 outputs and the voltage of this TL431 pressurizer, so that over-voltage protection function and light-emitting diode open-circuit-protection function to be provided.
And when the light-emitting diodes tube short circuit of wherein arbitrary light-emitting diode serial 30, then the conducting voltage Vf of this light-emitting diode serial 30 descends, for keeping the electric current of conducting in this light-emitting diode serial 30, the voltage difference at the drain electrode of this corresponding metal oxide semiconductcor field effect transistor 42 and source electrode two ends certainly will strengthen.For avoiding this metal oxide semiconductcor field effect transistor 42 to burn, need be set with a critical voltage value.When the drain electrode of arbitrary metal oxide semiconductcor field effect transistor 42 and source electrode moment, cross-pressure was greater than this critical voltage value the time; then Dui Ying this first switch element Sw1 conducting; and this second operational amplifier U2 sends a guard signal; closing voltage source, and reach the effect of light-emitting diode short-circuit protection.
When conducting when the conducting electric current of arbitrary light-emitting diode serial 30 is excessive; this excessive conducting electric current is to go up in the sense resistor Rs of this linear regulator 40 to produce corresponding excessive sensing voltage value; and then cause corresponding this second switch element Sw2 conducting; and become to making this second operational amplifier U2 to send a guard signal; to close voltage source; and reach overcurrent protection (over current protection, effect OCP).Also promptly this second operational amplifier U2 passes through the voltage of the relatively drain electrode of metal oxide semiconductcor field effect transistor 42 and the voltage of TL431 pressurizer; so that the light-emitting diode short-circuit protection function to be provided; this second operational amplifier U2 is by the voltage of the source electrode of comparison mos field effect transistor 42 and the voltage of this TL431 pressurizer, so that excess current protective function to be provided.
In addition; this multichannel LED drive system 1 also comprises a short-circuit protection circuit (short circuit protection; SCP) 82; this short-circuit protection circuit 82 comprises an auxiliary winding T, a protection diode Dp, a first transistor Q1, a transistor seconds Q2 and one the 3rd transistor Q3; should assist winding T to be electrically coupled to the primary side of the principal voltage device of this power supply changeover device 10; therefore, when power supply changeover device 10 1 starts, also open the short circuit current defencive function simultaneously.The negative electrode of this protection diode Dp is electrically connected at this auxiliary winding T, and its anode is electrically connected on the base stage of these a plurality of the first transistor Q1 and this transistor seconds Q2 and the collection utmost point of the 3rd transistor Q3 respectively.Short-circuit protection circuit 82 detects the voltage that power supply changeover device 10 is provided by this auxiliary winding T, and by the on off state of this protection diode Dp with control the first transistor Q1 and transistor seconds Q2, and reach short-circuit protection function.Wherein this first transistor Q1 and this transistor seconds Q2 are the two-carrier junction transistor of positive-negative-positive, and the 3rd transistor Q3 is the two-carrier junction transistor of NPN type.
In generally speaking; this power supply changeover device 10 provides a non-vanishing voltage to supply to give this a plurality of light-emitting diode serials 30; therefore; not conducting of this protection diode Dp; then these a plurality of the first transistor Q1 and the 3rd transistor Q3 conducting; and transistor seconds Q2 ends, and the power supply of changing through this power supply changeover device 10 directly is output in this a plurality of light-emitting diode serials 30.And when a filtering capacitor C short circuit of this rectification and filter unit 20, then should protection diode Dp conducting, and then make this transistor seconds Q2 conducting, to reach the function of short-circuit protection.
Comprehensive the above, the utility model is decided electric current/decide voltage controller 50 to detect conductings in the electric current of these a plurality of light-emitting diode serials 30 by this, reaches the output voltage values of this rectification and filter unit, to control the compensation that this electric pressure converter reaches voltage; And, these a plurality of linear regulators 40 are fine to adjust the current difference of conducting in 30 of this light-emitting diode serials, make these a plurality of light-emitting diode serials 30 be able to the electric current that conducting equates and reach sharing control, cause luminous with light stable intensity of these a plurality of light-emitting diodes.
Certainly; the utility model also can have other various embodiments; under the situation that does not deviate from the utility model spirit and essence thereof; those of ordinary skill in the art work as can make various corresponding changes and distortion according to the utility model, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the utility model.
Claims (9)
1. a multichannel LED drive system is characterized in that, comprises:
One power supply changeover device;
One rectification and filter unit are electrically connected at this power supply changeover device;
A plurality of light-emitting diode serials are made up of a plurality of light-emitting diodes that are connected in series, and these a plurality of light emitting diode string behaviors are connected in parallel in this rectification and filter unit;
A plurality of linear regulators, comprise quantity a plurality of switching diodes corresponding and the quantity a plurality of metal oxide semiconductcor field effect transistors corresponding, and respectively this linear regulator is electrically connected at respectively this light-emitting diode serial respectively accordingly with described light-emitting diode serial with described light-emitting diode serial;
Certain electric current/decide voltage controller is electrically connected at this a plurality of linear regulators;
One optically coupled isolator has a luminous end and a sensitization end, and this luminous end is electrically connected at this and decides electric current/decide voltage controller, decides electric current/decide the conducting electric current of voltage controller to receive this, and is sent to this sensitization end isolator;
One PWM controller is electrically connected at this power supply changeover device and this optically coupled isolator, to receive the perceptual signal that this optically coupled isolator transmitted and to control this power supply changeover device.
2. multichannel LED drive system according to claim 1 is characterized in that, also comprises a protected location, is electrically connected at this and decides electric current and decide voltage controller and this linear regulator, and this protected location comprises:
One pressurizer;
One in order to first operational amplifier of this rectification and filter unit output voltage and this stabilizer output voltage relatively, and the one negative input is electrically connected at this pressurizer; And
A plurality of protective resistors are electrically connected at a positive input and this rectification and the filter unit of this pressurizer.
3. multichannel LED drive system according to claim 2 is characterized in that, this protected location also comprises:
One second operational amplifier is electrically connected at this pressurizer;
A plurality of first switch elements are electrically connected at the drain electrode of this second operational amplifier and these a plurality of metal oxide semiconductcor field effect transistors; And
A plurality of second switch elements are electrically connected at the source electrode of this second operational amplifier and these a plurality of metal oxide semiconductcor field effect transistors.
4. multichannel LED drive system according to claim 2 is characterized in that this protected location also comprises a short-circuit protection circuit, and this short-circuit protection circuit comprises:
One in order to detect the auxiliary winding of voltage that this power supply changeover device provides, and is electrically coupled to this power supply changeover device;
One protection diode is electrically connected at this auxiliary winding;
One the first transistor is electrically connected at this protection diode;
One transistor seconds is electrically connected at this protection diode and this first transistor; And
One the 3rd transistor is electrically connected at this protection diode.
5. multichannel LED drive system according to claim 4 is characterized in that, this first transistor is a positive-negative-positive two-carrier junction transistor, and this transistor seconds is a NPN type two-carrier junction transistor.
6. multichannel LED drive system according to claim 1 is characterized in that, this power supply changeover device is an isolated DC/DC transducer.
7. multichannel LED drive system according to claim 1 is characterized in that, this is decided electric current/decide voltage controller and comprises the resistance-capacitance network that a pressurizer and is electrically connected at this pressurizer.
8. multichannel LED drive system according to claim 7 is characterized in that, this resistance-capacitance network comprises a resistor and a capacitor and decides electric current/the decide frequency response of voltage controller to determine this.
9. multichannel light-emitting diodes according to claim 1 shop drive system also comprises a PWM dim signal, be electrically connected on this linear regulator with should decide electric current/decide voltage controller.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011201358928U CN201976304U (en) | 2011-02-22 | 2011-04-26 | Multichannel light emitting diode driving system |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201120045539.0 | 2011-02-22 | ||
| CN201120045539 | 2011-02-22 | ||
| CN2011201358928U CN201976304U (en) | 2011-02-22 | 2011-04-26 | Multichannel light emitting diode driving system |
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| CN201976304U true CN201976304U (en) | 2011-09-14 |
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| CN2011201358928U Expired - Fee Related CN201976304U (en) | 2011-02-22 | 2011-04-26 | Multichannel light emitting diode driving system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104160782A (en) * | 2012-03-08 | 2014-11-19 | 赤多尼科英国有限公司 | Lamp unit power supply system |
| CN105322936A (en) * | 2015-12-02 | 2016-02-10 | 上海航空电器有限公司 | PBA switch circuit with insulation blocking function |
-
2011
- 2011-04-26 CN CN2011201358928U patent/CN201976304U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104160782A (en) * | 2012-03-08 | 2014-11-19 | 赤多尼科英国有限公司 | Lamp unit power supply system |
| US10057947B2 (en) | 2012-03-08 | 2018-08-21 | Tridonic Uk Ltd | Lamp unit power supply system |
| CN105322936A (en) * | 2015-12-02 | 2016-02-10 | 上海航空电器有限公司 | PBA switch circuit with insulation blocking function |
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