CN202679724U - LED drive circuit - Google Patents
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- CN202679724U CN202679724U CN 201220257301 CN201220257301U CN202679724U CN 202679724 U CN202679724 U CN 202679724U CN 201220257301 CN201220257301 CN 201220257301 CN 201220257301 U CN201220257301 U CN 201220257301U CN 202679724 U CN202679724 U CN 202679724U
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Abstract
Disclosed is an LED drive circuit, comprising a DC input power supply and at least one branch, wherein all the branches are connected between the positive terminal and the negative terminal of the DC input power supply; the branches comprise a plurality of LED sets composed of at least one LED via serial connection, bypass circuits corresponding to the LED sets, and a constant current source circuit; the input terminal of the bypass circuit is connected with the anode of the LED set while the output terminal of the bypass circuit is connected with the cathode of the LED set; the individual LED set and the corresponding single bypass circuit form an unit junction; a plurality of the unit junctions form a unit junction set via serial connection; the unit junction set is serially connected between the positive terminal of the DC input power supply and the input terminal of the constant current source circuit; the output terminal of the constant current source circuit is connected with the negative terminal of the DC input power supply; and the control terminals of all the bypass circuits are connected with the drive terminal of the constant current source circuit. The LED drive circuit of the utility model features little linear loss, high reliability, simple circuit structure, and small size, and the drive circuit can be partly or completely integrated.
Description
Technical field
The utility model relates to LED general illumination field, refers in particular to a kind of led drive circuit.
Background technology
LED has the remarkable advantages such as luminous efficiency is high, the life-span is long as a kind of new type light source.Because LED is the current mode device, therefore, must control the electric current that flows through LED during use, usually adopt current constant mode to drive.In addition, drive circuit also should have high efficiency, low cost, small size and can be suitable with LED useful life etc. advantage.
The simplest led drive circuit as shown in Figure 1, usually many LED are cascaded with a current-limiting resistance, are connected to the DC power supply after DC power supply or AC power are passed through rectifying and wave-filtering again, the non-constant of sort circuit constant current effect, the current-limiting resistance loss is also very large.
More, can adopt the Linear CCS drives, as shown in Figure 2, the Linear CCS circuit tandem drive of a plurality of LED by being consisted of by devices such as field effect transistor (or triode) Q1.Well controlled the electric current that flows through LED under this type of drive certain condition, but, to the input voltage that has certain limit to change, input voltage is crossed when hanging down, LED can't light, when input voltage is higher, removes the outer voltage of LED conduction voltage drop and drop to fully on the constant-current source, the linear impairments of whole drive circuit is still very large.
The input voltage of input voltage, especially wider range that certain limit is changed, industrial quarters adopts the Switching Power Supply with constant current function to come driving LED usually, as shown in Figure 3.In constant-current driving LED, this drive circuit can reduce linear impairments to the full extent, but, usually Switching Power Supply must be used the devices such as the large volume such as electric capacity, inductance and power semiconductor, integrated circuit, has that volume is large, circuit is complicated, cost is high and produces the shortcoming such as electromagnetic interference.
China Patent Publication No. CN101137261B, open day on March 23rd, 2011, the utility model patent that name is called " device and the method that are used for driving LED " discloses a kind of AC power drive-type LED lamp device, to carry out the voltage of the signal after the rectification and the reference voltage of regulation compares to AC power, control flows into conducting and the cut-off of the drive current of the LED in the led array according to comparative result.According to this structure, can make when AC supply voltage is large more that the LED of more number lights, when alternating voltage hour lights the LED of lesser number, can improve thus the power efficiency of LED lamp device.But this utility model is very complicated, especially control unit 200, need to provide galvanic current to press by current-limiting resistor 104, maintenance capacitor 106 and voltage stabilizing didoe 201, also comprise reference resistance row 202, a plurality of comparator 203, a plurality of selection circuit of lighting LED, a plurality of switching circuit 205 that is consisted of by the or element, and its switching circuit 205 can only be in the state of being switched on or switched off, when certain switching circuit circuit operation, the variation of its terminal voltage can be applied on the floating current source, has increased the electric energy loss of circuit.
China Patent Publication No. CN102287785A, open day on December 21st, 2011, name is called " a kind of LED matrix and driving method thereof " and discloses a kind of LED matrix and driving method thereof, comprise rectification circuit, LED lamp string, be connected on constant-current source and switch control unit between rectification circuit and the LED lamp string, wherein, LED lamp string is divided into the n group, the connection in series-parallel of every group of LED lamp has control switch Ki, described control switch Ki links to each other with switch control unit, and LED lamp number is more than or equal to LED lamp number in the i group in the i+1 group.This utility model is by dividing into groups LED lamp string, every group of LED that different numbers are set, and control respectively the current switching of every group of LED lamp string by paralleling switch, simplify circuit design, reduced certain power loss, but the switch of this utility model LED lamp string controlled by control switch, and also will use forward-backward counter, voltage comparator, logic are selected the modules such as circuit, and structure is still very complicated.Equally, during the break-make of certain control switch Ki, the variation of control switch terminal voltage can be applied on the constant-current source, has increased the electric energy loss of circuit in this utility model.
The utility model content
The purpose of this utility model is to overcome defective of the prior art, and a kind of led drive circuit is provided.
The purpose of this utility model is to be achieved by following technical proposals:
A kind of led drive circuit, comprise direct-current input power supplying and at least one branch road, all branch roads are connected between direct-current input power supplying anode and the negative terminal, wherein branch road comprises the LED group that several are in series by at least one LED, can be operated in short circuit, bypass circuit and a constant-current source circuit that several of open circuit or linear zone are corresponding with the LED group, the anodic bonding of the input of bypass circuit and LED group, the output of bypass circuit is connected with the negative electrode of LED group, the single led group of single bypass circuit Component units joint corresponding with it, Component units joint group after several unit joint series connection, unit joint group is connected between the input of the anode of direct-current input power supplying and constant-current source circuit, the output of constant-current source circuit is connected with the negative terminal of direct-current input power supplying, and the control end of all bypass circuits is connected with the drive end of constant-current source circuit.
The operation principle of drive circuit is that constant-current source circuit detection branch size of current drives bypass circuit and is operated in short circuit, open circuit or linear zone.Be specially: constant-current source circuit detects the electric current that flows through this branch road, when electric current during less than the constant current value set, constant-current source circuit drive end level changes (rising), so that certain bypass circuit terminal voltage that is operated in linear zone reduces, or the bypass circuit of some is operated in short-circuit condition, thereby so that the terminal voltage of corresponding LED group reduces or by short circuit, branch current increases; On the contrary, when electric current during greater than the constant current value set, the drive end level of constant-current source circuit changes (reduction), so that certain bypass circuit terminal voltage that is operated in linear zone raises, or the bypass circuit of some is operated in open-circuit condition, the terminal voltage of corresponding LED group raises or conducting, and branch current reduces.
Branch road of the utility model has and only has a bypass circuit to be operated in linear zone, this linear voltage drop is less than the forward voltage drop of parallel connection LED group with it, remaining bypass circuit or open-circuit working are at cut-off region, perhaps short circuit is operated in the conducting district, and the pressure drop on the constant-current source circuit is also very little in this case, therefore, the utility model linear impairments is very little.
When the input overvoltage, during the input range that exceeds design such as input voltage surpasses all LED in other words when organizing all conductings forward voltage drop, all bypass circuits are all opened a way, the outer overvoltage part of forward voltage drop when removing all LED group conductings all drops on the constant-current source circuit, have linear impairments on the constant-current source circuit this moment, and this loss increases with superpotential increase.
Bypass circuit can also have the voltage limit function: bypass circuit and LED organize parallel operation, can improve the reliability of drive circuit.The voltage limit function can lose efficacy in the LED group in parallel with this bypass circuit, under some LED open circuit situation, the voltage at restriction bypass circuit two ends, prevent whole branch road open circuit, bypass circuit self lost efficacy, also only affect LED group in parallel with it such as open circuit or short circuit, do not affect the work of other LED group.
As a kind of preferred version, branch road comprises that also at least one LED is connected between the anode of the anode of direct-current input power supplying and unit joint group.If part LED group is in parallel with bypass circuit, whole drive circuit has reduced the quantity of bypass circuit, has further reduced cost.
As a kind of preferred version, bypass circuit comprises field effect transistor Q30, and the drain electrode of field effect transistor Q30 connects the input of bypass circuit, and the source electrode of field effect transistor Q30 connects the output of bypass circuit, and the grid of field effect transistor Q30 connects the control end of bypass circuit.
As a kind of preferred version, bypass circuit comprises field effect transistor Q30, diode D30 and resistance R 30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, the source electrode of field effect transistor Q30 connects the output of bypass circuit, the control end of the anodic bonding bypass circuit of diode D30, the negative electrode of diode D30 connects the grid of field effect transistor Q30, and an end of resistance R 30 connects the negative electrode of diode D30, and the other end of resistance R 30 connects the source electrode of field effect transistor Q30.Resistance R 30 and diode D30 are used to protect field effect transistor Q30, prevent that the grid of field effect transistor Q30, source electrode from being punctured by counter voltage.
As a kind of preferred version, bypass circuit comprises field effect transistor Q30, diode D30, diode D31 and resistance R 30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, the source electrode of field effect transistor Q30 connects the output of bypass circuit, the control end of the anodic bonding bypass circuit of diode D30, the negative electrode of diode D30 connects the grid of field effect transistor Q30, one end of resistance R 30 connects the negative electrode of diode D30, the other end of resistance R 30 connects the source electrode of field effect transistor Q30, the drain electrode of the anodic bonding field effect transistor Q30 of diode D31, the negative electrode of diode D31 connects the grid of field effect transistor Q30.Diode D31 provide overvoltage protection: when some LED of LED group open a way; the drain electrode of field effect transistor Q30, voltage between source electrodes raise; diode D31 conducting; the relative source voltage of the grid of field effect transistor pipe Q30 raises; field effect transistor pipe Q30 will be operated in the linear zone of voltage limit, improve the reliability of drive circuit.
As a kind of preferred version, bypass circuit comprises field effect transistor Q30, diode D30, diode D31, resistance R 30 and voltage-stabiliser tube Z30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, the source electrode of field effect transistor Q30 connects the output of bypass circuit, the control end of the anodic bonding bypass circuit of diode D30, the negative electrode of diode D30 connects the grid of field effect transistor Q30, one end of resistance R 30 connects the negative electrode of diode D30, the other end of resistance R 30 connects the source electrode of field effect transistor Q30, the anode of the anodic bonding voltage-stabiliser tube Z30 of diode D31, the negative electrode of voltage-stabiliser tube Z30 connects the drain electrode of field effect transistor Q30, and the negative electrode of diode D31 connects the grid of field effect transistor Q30.Puncture voltage by voltage-stabiliser tube Z30 and field effect transistor pipe Q30 open threshold and improve or adjust and set voltage limiting value.
As a kind of preferred version, constant-current source circuit comprises field effect transistor Q40, triode Q41, resistance R 40 and resistance R 41, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 is the base stage of connecting triode Q41 also, the emitter of triode Q41 connects the output of constant-current source circuit, the end of the collector electrode while contact resistance R41 of triode Q41 and the drive end of constant-current source circuit, the other end of resistance R 41 connects the anode of direct-current input power supplying, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit, and the grid of field effect transistor Q40 connects the drive end of constant-current source circuit.
As a kind of preferred version, constant-current source circuit comprises field effect transistor Q40, triode Q41, resistance R 40, resistance R 41, NPN type triode Q42 and positive-negative-positive triode Q43, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 is the base stage of connecting triode Q41 also, the emitter of triode Q41 connects the output of constant-current source circuit, the end of the collector electrode contact resistance R41 of triode Q41, the other end of resistance R 41 connects the anode of direct-current input power supplying, triode Q42 and triode Q43 consist of the totem connection, the base stage of the base stage of triode Q42 and triode Q43 is connected to the collector electrode of triode Q41 jointly, the collector electrode of triode Q42 connects the anode of direct current input source, the collector electrode of triode Q43 connects the output of constant-current source circuit, the emitter of triode Q42 is connected emitter and is jointly connected the drive end of constant-current source circuit with triode Q43, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit, and the grid of field effect transistor Q40 connects the drive end of constant-current source circuit.The totem connection of triode Q42 and triode Q43 has promoted the driving force of constant-current source circuit, has alleviated the loss of resistance R 41.
As a kind of preferred version, constant-current source circuit comprises field effect transistor Q40, integrated circuit (IC) 40, resistance R 40, resistance R 41, NPN type triode Q42 and positive-negative-positive triode Q43, integrated circuit (IC) 40 is the TL431 circuit, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 also connects the reference edge of integrated circuit (IC) 40, the output of the anodic bonding constant-current source circuit of integrated circuit (IC) 40, the end of the negative electrode contact resistance R41 of integrated circuit (IC) 40, the other end of resistance R 41 connects the anode of direct-current input power supplying, triode Q42 and triode Q43 consist of the totem connection, the base stage of the base stage of triode Q42 and triode Q43 is connected to the anode of integrated circuit (IC) 40 jointly, the collector electrode of triode Q42 connects the anode of direct current input source, the collector electrode of triode Q43 connects the output of constant-current source circuit, the emitter of triode Q42 is connected emitter and is jointly connected the drive end of constant-current source circuit with triode Q43, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit, and the grid of field effect transistor Q40 connects the drive end of constant-current source circuit.Q41 compares with triode, and the reference voltage of the reference edge of integrated circuit (IC) 40 is more stable, and the electric current of constant-current source is also just more stable.
As a kind of preferred version, constant-current source circuit comprises field effect transistor Q40, integrated operational amplifier IC41, resistance R 40 and reference circuit, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 also connects the negative input of integrated operational amplifier IC41, the electrode input end of integrated operational amplifier IC41 connects reference circuit, reference circuit also connects the output of constant-current source circuit, the output of integrated operational amplifier IC41 is connected grid and is jointly connected the drive end of constant-current source circuit with field effect transistor Q40, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit.
As a kind of preferred version, direct-current input power supplying is the power supply of exporting after the rectification of AC power process rectifier bridge.
As a kind of preferred version, direct-current input power supplying is the rectification of AC power process rectifier bridge, and the power supply of exporting behind the paddy circuit is filled out in series connection.Fill out the paddy circuit and can improve the power factor (PF) of AC/DC conversion, improve the operating efficiency of drive circuit.
As a kind of preferred version, driving circuit section or all integrate.Wherein, LED group can be integrated with bypass circuit, and bypass circuit can be integrated with constant-current source circuit, and LED group, bypass circuit and constant-current source circuit can be jointly integrated, and is more, LED group, bypass circuit, constant-current source circuit, rectification circuit and fill out the paddy circuit can be jointly integrated.
The beneficial effects of the utility model are, linear impairments is very little, and reliability is very high, and circuit structure is very simple, and volume is little, and drive circuit can be partly or entirely integrated.
Description of drawings
Fig. 1 is a kind of drive circuit figure of prior art;
Fig. 2 is the another kind of drive circuit figure of prior art;
Fig. 3 is the third drive circuit figure of prior art;
Fig. 4 is a kind of circuit theory connection layout of the present utility model;
Fig. 5 is a kind of circuit diagram of the utility model bypass circuit;
Fig. 6 is the another kind of circuit diagram of the utility model bypass circuit;
Fig. 7 is the third circuit diagram of the utility model bypass circuit;
Fig. 8 is the 4th kind of circuit diagram of the utility model bypass circuit;
Fig. 9 is a kind of circuit diagram of the utility model constant-current source circuit;
Figure 10 is the another kind of circuit diagram of the utility model constant-current source circuit;
Figure 11 is the third circuit diagram of the utility model constant-current source circuit;
Figure 12 is the 4th kind of circuit diagram of the utility model constant-current source circuit;
Figure 13 be the utility model AC power through the rectifier bridge rectification and the circuit diagram of direct-current input power supplying;
Figure 14 rectification that is the utility model AC power through rectifier bridge connect again fill out the paddy circuit and the circuit diagram of direct-current input power supplying;
Figure 15 is another kind of circuit theory connection layout of the present utility model;
Figure 16 is the circuit theory connection layout that drive circuit of the present utility model has two branch roads.
Wherein: 1, direct-current input power supplying, 2, LED group, 3, bypass circuit, 4, constant-current source circuit, 5, rectifier bridge, 6, fill out the paddy circuit, 31, the input of bypass circuit, 32, the output of bypass circuit, 33, the control end of bypass circuit, 41, the input of constant-current source circuit, 42, the output of constant-current source circuit, 43, the drive end of constant-current source circuit.
Embodiment
Below in conjunction with drawings and Examples the utility model is further described.
Embodiment 1: a kind of led drive circuit, its circuit theory connection layout as shown in Figure 4, comprise direct-current input power supplying 1 and a branch road, branch road comprises the LED group 2 that several are in series by at least one LED, bypass circuit 3 and constant-current source circuit 4, the input 31 of bypass circuit and the anodic bonding of LED group, the output 32 of bypass circuit is connected with the negative electrode of LED group, the single led group of single bypass circuit Component units joint corresponding with it, Component units joint group after several unit joint series connection, unit joint group is connected between the input 41 of the anode of direct-current input power supplying and constant-current source circuit, the output 42 of constant-current source circuit is connected with the negative terminal of direct-current input power supplying, and the control end 33 of all bypass circuits is connected with the drive end 43 of constant-current source circuit.The circuit diagram of bypass circuit comprises field effect transistor Q30 as shown in Figure 5, and the drain electrode of field effect transistor Q30 connects the input of bypass circuit, and the source electrode of field effect transistor Q30 connects the output of bypass circuit, and the grid of field effect transistor Q30 connects the control end of bypass circuit.The circuit diagram of constant-current source circuit as shown in Figure 9, comprise field effect transistor Q40, triode Q41, resistance R 40 and resistance R 41, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 is the base stage of connecting triode Q41 also, the emitter of triode Q41 connects the output of constant-current source circuit, the end of the collector electrode while contact resistance R41 of triode Q41 and the drive end of constant-current source circuit, the other end of resistance R 41 connects the anode of direct-current input power supplying, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit, and the grid of field effect transistor Q40 connects the drive end of constant-current source circuit.
Constant-current source circuit detects the electric current that flows through branch road, when electric current during less than the constant current value set, constant-current source circuit drive end level changes (rising), so that certain bypass circuit terminal voltage that is operated in linear zone reduces, or the bypass circuit of some is operated in short-circuit condition, thereby so that the terminal voltage of corresponding LED group reduces or by short circuit, branch current increases; On the contrary, when electric current during greater than the constant current value set, the drive end level of constant-current source circuit changes (reduction), so that certain bypass circuit terminal voltage that is operated in linear zone raises, or the bypass circuit of some is operated in open-circuit condition, the terminal voltage of corresponding LED group raises or conducting, and branch current reduces.When the input overvoltage, during the input range that exceeds design such as input voltage surpasses all LED in other words when organizing all conductings forward voltage drop, all bypass circuits are all opened a way, the outer overvoltage part of forward voltage drop when removing all LED group conductings all drops on the constant-current source circuit, have linear impairments on the constant-current source circuit this moment, and this loss increases with superpotential increase.
Embodiment 2: a kind of led drive circuit, the circuit diagram of its bypass circuit as shown in Figure 6, bypass circuit comprises field effect transistor Q30, diode D30 and resistance R 30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, the source electrode of field effect transistor Q30 connects the output of bypass circuit, the control end of the anodic bonding bypass circuit of diode D30, the negative electrode of diode D30 connects the grid of field effect transistor Q30, one end of resistance R 30 connects the negative electrode of diode D30, and the other end of resistance R 30 connects the source electrode of field effect transistor Q30.Added resistance R 30 and diode D30, be used for protecting field effect transistor Q30, prevented that the grid of field effect transistor Q30, source electrode from being punctured by counter voltage.Other circuit structure is identical with embodiment 1 with principle.
Embodiment 3: a kind of led drive circuit, the circuit diagram of its bypass circuit as shown in Figure 7, bypass circuit comprises field effect transistor Q30, diode D30, diode D31 and resistance R 30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, the source electrode of field effect transistor Q30 connects the output of bypass circuit, the control end of the anodic bonding bypass circuit of diode D30, the negative electrode of diode D30 connects the grid of field effect transistor Q30, one end of resistance R 30 connects the negative electrode of diode D30, the other end of resistance R 30 connects the source electrode of field effect transistor Q30, the drain electrode of the anodic bonding field effect transistor Q30 of diode D31, the negative electrode of diode D31 connects the grid of field effect transistor Q30.Diode D31 provide overvoltage protection: when some LED of LED group open a way; the drain electrode of field effect transistor Q30, voltage between source electrodes raise; diode D31 conducting; the relative source voltage of the grid of field effect transistor Q30 raises; field effect transistor Q30 will be operated in the linear zone of voltage limit, improve the reliability of drive circuit.Other circuit structure is identical with embodiment 2 with principle.
Embodiment 4: a kind of led drive circuit, the circuit diagram of its bypass circuit as shown in Figure 8, bypass circuit comprises field effect transistor Q30, diode D30, resistance R 30, diode D31 and voltage-stabiliser tube Z30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, the source electrode of field effect transistor Q30 connects the output of bypass circuit, the control end of the anodic bonding bypass circuit of diode D30, the negative electrode of diode D30 connects the grid of field effect transistor Q30, one end of resistance R 30 connects the negative electrode of diode D30, the other end of resistance R 30 connects the source electrode of field effect transistor Q30, the anode of the anodic bonding voltage-stabiliser tube Z30 of diode D31, the negative electrode of voltage-stabiliser tube Z30 connects the drain electrode of field effect transistor Q30, and the negative electrode of diode D31 connects the grid of field effect transistor Q30.Puncture voltage by voltage-stabiliser tube Z30 and field effect transistor Q30 open threshold and improve or adjust and set voltage limiting value.Other circuit structure is identical with embodiment 2 with principle.
Embodiment 5: a kind of led drive circuit, the circuit diagram of constant-current source circuit as shown in figure 10, comprise field effect transistor Q40, triode Q41, resistance R 40, resistance R 41, NPN type triode Q42 and positive-negative-positive triode Q43, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 is the base stage of connecting triode Q41 also, the emitter of triode Q41 connects the output of constant-current source circuit, the end of the collector electrode contact resistance R41 of triode Q41, the other end of resistance R 41 connects the anode of direct-current input power supplying, triode Q42 and triode Q43 consist of the totem connection, the base stage of the base stage of triode Q42 and triode Q43 is connected to the collector electrode of triode Q41 jointly, the collector electrode of triode Q42 connects the anode of direct current input source, the collector electrode of triode Q43 connects the output of constant-current source circuit, the emitter of triode Q42 is connected emitter and is jointly connected the drive end of constant-current source circuit with triode Q43, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit, and the grid of field effect transistor Q40 connects the drive end of constant-current source circuit.
Embodiment: 6: a kind of led drive circuit, the circuit diagram of constant-current source circuit as shown in figure 11, comprise field effect transistor Q40, integrated circuit (IC) 40, resistance R 40, resistance R 41, NPN type triode Q42 and positive-negative-positive triode Q43, integrated circuit (IC) 40 is the TL431 circuit, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 also connects the reference edge of integrated circuit (IC) 40, the output of the anodic bonding constant-current source circuit of integrated circuit (IC) 40, the end of the negative electrode contact resistance R41 of integrated circuit (IC) 40, the other end of resistance R 41 connects the anode of direct-current input power supplying, triode Q42 and triode Q43 consist of the totem connection, the base stage of the base stage of triode Q42 and triode Q43 is connected to the anode of integrated circuit (IC) 40 jointly, the collector electrode of triode Q42 connects the anode of direct current input source, the collector electrode of triode Q43 connects the output of constant-current source circuit, the emitter of triode Q42 is connected emitter and is jointly connected the drive end of constant-current source circuit with triode Q43, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit, and the grid of field effect transistor Q40 connects the drive end of constant-current source circuit.Other circuit structure is identical with embodiment 1 with principle.
Embodiment 7: a kind of led drive circuit, the circuit diagram of constant-current source circuit as shown in figure 12, constant-current source circuit comprises field effect transistor Q40, integrated operational amplifier IC41, resistance R 40 and reference circuit, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 also connects the negative input of integrated operational amplifier IC41, the electrode input end of integrated operational amplifier IC41 connects reference circuit, reference circuit also connects the output of constant-current source circuit, the output of integrated operational amplifier IC41 is connected grid and is jointly connected the drive end of constant-current source circuit with field effect transistor Q40, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit.Other circuit structure is identical with embodiment 1 with principle.
Embodiment 8: a kind of led drive circuit, its direct-current input power supplying part as shown in figure 13, alternating current AC is that civil power is such as 220V or 110V alternating current, through the required DC power supply of output after rectifier bridge 5 rectifications.Other circuit structure is identical with embodiment 1 with principle.
Embodiment 9: a kind of led drive circuit, its direct-current input power supplying part as shown in figure 14, alternating current AC be civil power such as 220V or 110V alternating current, after rectifier bridge 5 rectifications, fill out the required DC power supply of paddy circuit 6 rear outputs by series connection.Other circuit structure is identical with embodiment 1 with principle.
Embodiment 10: a kind of led drive circuit, its circuit theory connection layout as shown in figure 15, branch road comprises that also a plurality of LED are connected between the anode of the anode of direct-current input power supplying and unit joint group.Other circuit structure is identical with embodiment 1 with principle.
Embodiment 11: the circuit theory connection layout that a kind of led drive circuit, drive circuit have two branch roads as shown in figure 16, two branch roads share direct-current input power supplyings.
Specific embodiment described herein only is to the explanation for example of the utility model spirit.The utility model person of ordinary skill in the field can make various modifications or replenishes or adopt similar mode to substitute described specific embodiment; such as the field effect transistor of using in the alternative drive circuits such as employing triode; or increase signal amplification circuit further to reduce the loss on the sampling resistor; or adopt other circuital current to detect; or increase constant flow regulation to reach the purpose of light modulation; etc., all should be regarded as belonging to protection range of the present utility model.
Although this paper has more used the terms such as linear impairments, cut-off, conducting, do not get rid of the possibility of using other term.Using these terms only is in order to describe more easily and explain essence of the present utility model, and they are construed to any additional restriction all is contrary with the utility model spirit.
Claims (10)
1. led drive circuit, it is characterized in that, comprise direct-current input power supplying (1) and at least one branch road, all branch roads are connected between direct-current input power supplying anode and the negative terminal, wherein branch road comprises the LED group (2) that several are in series by at least one LED, can be operated in short circuit, bypass circuit (3) and a constant-current source circuit (4) that several of open circuit or linear zone are corresponding with the LED group, the anodic bonding of the input of bypass circuit (31) and LED group, the output of bypass circuit (32) is connected with the negative electrode of LED group, the single led group of single bypass circuit Component units joint corresponding with it, Component units joint group after several unit joint series connection, unit joint group is connected between the anode of direct-current input power supplying and the input of constant-current source circuit (41), the output of constant-current source circuit (42) is connected with the negative terminal of direct-current input power supplying, and the control end of all bypass circuits (33) is connected with the drive end (43) of constant-current source circuit.
2. a kind of led drive circuit according to claim 1 is characterized in that, branch road comprises that also at least one LED is connected between the anode of the anode of direct-current input power supplying and unit joint group.
3. a kind of led drive circuit according to claim 1 and 2, it is characterized in that, bypass circuit comprises field effect transistor Q30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, the source electrode of field effect transistor Q30 connects the output of bypass circuit, and the grid of field effect transistor Q30 connects the control end of bypass circuit.
4. a kind of led drive circuit according to claim 1 and 2, it is characterized in that, bypass circuit comprises field effect transistor Q30, diode D30 and resistance R 30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, field effect transistor Q30 source electrode connects the output of bypass circuit, the control end of the anodic bonding bypass circuit of diode D30, the negative electrode of diode D30 connects the grid of field effect transistor Q30, one end of resistance R 30 connects the negative electrode of diode D30, and the other end of resistance R 30 connects the source electrode of field effect transistor Q30.
5. a kind of led drive circuit according to claim 1 and 2, it is characterized in that, bypass circuit comprises field effect transistor Q30, diode D30, diode D31, resistance R 30 and voltage-stabiliser tube Z30, the drain electrode of field effect transistor Q30 connects the input of bypass circuit, the source electrode of field effect transistor Q30 connects the output of bypass circuit, the control end of the anodic bonding bypass circuit of diode D30, the negative electrode of diode D30 connects the grid of field effect transistor Q30, one end of resistance R 30 connects the negative electrode of diode D30, the other end of resistance R 30 connects the source electrode of field effect transistor Q30, the anode of the anodic bonding voltage-stabiliser tube Z30 of diode D31, the negative electrode of voltage-stabiliser tube Z30 connects the drain electrode of field effect transistor Q30, and the negative electrode of diode D31 connects the grid of field effect transistor Q30.
6. a kind of led drive circuit according to claim 1 and 2, it is characterized in that, described constant-current source circuit comprises field effect transistor Q40, triode Q41, resistance R 40 and resistance R 41, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 is the base stage of connecting triode Q41 also, the emitter of triode Q41 connects the output of constant-current source circuit, the end of the collector electrode while contact resistance R41 of triode Q41 and the drive end of constant-current source circuit, the other end of resistance R 41 connects the anode of direct-current input power supplying, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit, and the grid of field effect transistor Q40 connects the drive end of constant-current source circuit.
7. a kind of led drive circuit according to claim 1 and 2, it is characterized in that, described constant-current source circuit comprises field effect transistor Q40, triode Q41, resistance R 40, resistance R 41, NPN type triode Q42 and positive-negative-positive triode Q43, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 is the base stage of connecting triode Q41 also, the emitter of triode Q41 connects the output of constant-current source circuit, the end of the collector electrode contact resistance R41 of triode Q41, the other end of resistance R 41 connects the anode of direct-current input power supplying, triode Q42 and triode Q43 consist of the totem connection, the base stage of the base stage of triode Q42 and triode Q43 is connected to the collector electrode of triode Q41 jointly, the collector electrode of triode Q42 connects the anode of direct current input source, the collector electrode of triode Q43 connects the output of constant-current source circuit, the emitter of triode Q42 is connected emitter and is jointly connected the drive end of constant-current source circuit with triode Q43, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit, and the grid of field effect transistor Q40 connects the drive end of constant-current source circuit.
8. a kind of led drive circuit according to claim 1 and 2, it is characterized in that, described constant-current source circuit comprises field effect transistor Q40, integrated operational amplifier IC41, resistance R 40 and reference circuit, resistance R 40 is current sense resistor, one end of resistance R 40 connects the source electrode of field effect transistor Q40, the other end of resistance R 40 connects the output of constant-current source circuit, the source electrode of field effect transistor Q40 also connects the negative input of integrated operational amplifier IC41, the electrode input end of integrated operational amplifier IC41 connects reference circuit, reference circuit also connects the output of constant-current source circuit, the output of integrated operational amplifier IC41 is connected grid and is jointly connected the drive end of constant-current source circuit with field effect transistor Q40, the drain electrode of field effect transistor Q40 connects the input of constant-current source circuit.
9. a kind of led drive circuit according to claim 1 and 2 is characterized in that, direct-current input power supplying (1) is AC power through rectifier bridge (5) rectification, or AC power through rectifier bridge (5) rectification connect again and fill out the power supply of output behind the paddy circuit (6).
10. a kind of led drive circuit according to claim 1 and 2 is characterized in that, driving circuit section or all integrate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220257301 CN202679724U (en) | 2012-06-04 | 2012-06-04 | LED drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220257301 CN202679724U (en) | 2012-06-04 | 2012-06-04 | LED drive circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202679724U true CN202679724U (en) | 2013-01-16 |
Family
ID=47500591
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220257301 Withdrawn - After Issue CN202679724U (en) | 2012-06-04 | 2012-06-04 | LED drive circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202679724U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102740561A (en) * | 2012-06-04 | 2012-10-17 | 杭州展顺科技有限公司 | LED (Light Emitting Diode) driving circuit |
| WO2014173200A1 (en) * | 2013-04-25 | 2014-10-30 | 合肥云杉光电科技有限公司 | Integrated circuit, and method of taking electric power from low voltage bypass for alternating current directly driven led |
-
2012
- 2012-06-04 CN CN 201220257301 patent/CN202679724U/en not_active Withdrawn - After Issue
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102740561A (en) * | 2012-06-04 | 2012-10-17 | 杭州展顺科技有限公司 | LED (Light Emitting Diode) driving circuit |
| WO2014173200A1 (en) * | 2013-04-25 | 2014-10-30 | 合肥云杉光电科技有限公司 | Integrated circuit, and method of taking electric power from low voltage bypass for alternating current directly driven led |
| US9301355B2 (en) | 2013-04-25 | 2016-03-29 | Hefei Spruce Optoelectronic Technology Co., Ltd. | Method of taking power with low-voltage bypass by integrated circuit for AC direct driving LEDs and the integrated circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20130116 Effective date of abandoning: 20140604 |
|
| RGAV | Abandon patent right to avoid regrant |