CN207219119U - A kind of HVDC LED constant current circuit - Google Patents

Abstract

The utility model discloses a kind of HVDC LED constant current circuit, including centrally connected power supply supply unit, multiple LED strings, multiple current regulator diodes, it is characterised in that：Connected on each described LED string a corresponding current regulator diode, the LED string forms a branch road with the current regulator diode, and described branch circuit parallel connection is between the output bus anode and output bus negative terminal of centrally connected power supply supply unit.The utility model uses HVDC centrally connected power supply mode power, power supply output connects LED string and constant-current circuit, and every a string of high-voltage LEDs use independent constant-current circuit constant current, and every group of circuit supports PWM light modulations, the application of the circuit solves the problems such as conventional low LED power supplies and constant-current circuit device cost are high, input power factor is low, power-efficient is low, controllability is low.

Description

A kind of HVDC LED constant current circuit

Technical field

It the utility model is related to LED circuit technical field, more particularly to a kind of HVDC LED constant current circuit.

Background technology

Light emitting diode (LED) solid light source has the advantages that high luminous efficiency, environmental protection, long-life, is described as the 5th generation Lighting source.Development of Novel LED illumination is current light source and an important directions of lighting engineering development.LED light source is in many In, it is trend of the times that incandescent lamp and fluorescent lamp are replaced in particularly extraordinary application, as traffic lights, extraordinary landscape shine The high extraordinary application of the security requirements such as bright, colliery railway.But LED engineering use cost is higher at present, to LED illumination light Certain resistance also be present in the popularization in source.

In LED drive circuit, low-voltage LED constant-current drive technology is more, and low-voltage driving technical difficulty is smaller, main suitable Together in LED flashlight, and some portable equipments, to the occasion applied to 220V Alternating Current Power Supplies, to increase AC/DC power supply Part, there is provided relatively low DC voltage, this scheme can greatly improve cost.Using constant-current drive technology, phase can be obtained With light intensity and color, the forward current for flowing through each LED is persistently consistent, thus hue coordinate will not be offset.Pass through electricity It the regulation of stream, can both reach the purpose of light modulation, coordinate offset will not be acted on behalf of again.Therefore at present in development constant current driving skill Art, but the circuit of constant current driving is high with respect to constant voltage drive circuit complexity, and mainly low pressure applications；If using In terms of high pressure, then the scheme using the series connection of plurality of LEDs light fixture is had to, to need high-voltage constant-current circuit, and to ensure LED perseverances Current circuit securely and reliably works, and has that the electric current that ensure to flow through every string LED is identical, and the thus constant current to high-voltage LED device carries Requirements at the higher level are gone out.

Also there are some companies to release application scheme, but be suitable only for the application scenario of low pressure mostly.Because should to low pressure It is not easy to go wrong with LED lamp, technical difficulty is smaller；It is required because of the LED lamp of different capacity for high-voltage applications Its electric current flowed through is not quite similar, and during such as multiple LED lamps series connection, because of the unstability of electric current, causes the dissipation work of LED lamp Rate becomes big, and the situation for burning out LED lamp also often occurs.

Utility model content

Technical problem to be solved in the utility model is to provide one kind and uses HVDC centrally connected power supply mode power, electricity Source output connects LED string and constant-current circuit, and every a string of high-voltage LEDs use independent constant-current circuit constant current, and every group of electricity PWM light modulations are supported on road, and the application of the circuit solves conventional low LED power supplies and constant-current circuit device cost height, input power The HVDC LED constant current circuit for the problems such as factor is low, power-efficient is low, controllability is low.

In order to solve the above technical problems, the utility model provides a kind of HVDC LED constant current circuit, including centrally connected power supply Supply unit, multiple LED strings, multiple current regulator diodes, it is characterised in that：Connect one on each described LED string Individual corresponding current regulator diode, the LED string form a branch road with the current regulator diode, and described branch circuit parallel connection is in collection Between the output bus anode and output bus negative terminal of middle power supply device.

Further, the number of the current regulator diode is equal with the number of LED string, in described each LED string LED number it is all equal, each LED lamp in the LED string is high-voltage LED light fixture.

Further, the HVDC LED constant current circuit include first voltage detection control circuit, LED string I with First constant-current circuit, the voltage detecting and controling circuit include voltage detecting and controling circuit triode V2, the first divider resistance R1 With the second divider resistance R3, one end of two divider resistances connects voltage detecting and controling circuit triode V2 base stage simultaneously, the The one divider resistance R1 other end connects the negative terminal of the LED string I, and the second divider resistance R3 other end connection power supply is born Pole, first voltage detection control circuit triode V2 colelctor electrode connect the first constant-current circuit metal-oxide-semiconductor V1 grid, first voltage The emitter stage for detecting control circuit triode V2 connects the negative terminal of the LED string I, and it is permanent that first constant-current circuit includes first Current circuit metal-oxide-semiconductor V1, a first current-limiting resistance R2, a first current sense resistor R4 and the pole of the first constant-current circuit three Pipe V3, the first constant-current circuit metal-oxide-semiconductor V1 drain electrode connect the negative terminal of the first LED string with the first current-limiting resistance R2 one end, the One constant-current circuit metal-oxide-semiconductor V1 source electrode and the first current sense resistor R4 one end connect the first constant-current circuit triode V3 simultaneously Base stage, the first current sense resistor R2 other end and the first constant-current circuit triode V3 emitter stage is connected to the negative of power supply Pole, the first constant-current circuit metal-oxide-semiconductor V1 grid connect the first current-limiting resistance R2 other end, first voltage detection control electricity simultaneously The colelctor electrode of road triode V2 colelctor electrode and the first constant-current circuit triode V3.

Compared with prior art, the beneficial effects of the utility model are：

1st, the utility model uses HVDC centrally connected power supply mode power, and power supply output connects LED string and constant-current circuit, And every a string of high-voltage LEDs use independent constant-current circuit constant current, and every group of circuit supports PWM light modulations, the application of the circuit Solve conventional low LED power supplies and constant-current circuit device this height, input power factor is low, power-efficient is low, controllability is low etc. Problem.

2nd, every a string of LED of the present utility model use independent constant-current circuit, and LED light source is separate, in any a string Any one LED failure all without influence other string LED normal work；And circuit provided by the utility model can To support long-distance transmissions, HVDC Transmission pressure drop ratio is relatively low, both ensure that the reliability that light fixture uses, has met open air The illumination application system of long-distance transmissions power supply.

Brief description of the drawings

Fig. 1 is the structured flowchart for the LED constant current circuit that the utility model provides embodiment.

Fig. 2 is electrical block diagram of the present utility model.

Label in figure：

1- centrally connected power supply supply unit 2-LED lamp string I 3-LED lamp strings II

4-LED lamp string III 22- current regulator diode I 33- current regulator diodes II

44- current regulator diodes III.

Embodiment

Below to being elaborated with reference to accompanying drawing to preferred embodiment of the present utility model, so that the advantages of the utility model It can be easier to be readily appreciated by one skilled in the art with feature, it is apparent clear and definite so as to be made to the scope of protection of the utility model Define.

It is shown in Figure 1, a kind of HVDC LED constant current circuit, including centrally connected power supply supply unit 1, LED string I2, LED string II3, LED string III4, current regulator diode I22, current regulator diode II33, current regulator diode III44, the LED The I2 and current regulator diode I22 that goes here and there connects, and forms tie point；LED string II3 and current regulator diode II33 series connection, composition second Branch road；Current regulator diode II33 and current regulator diode III44 series connection, forms the 3rd branch road；The tie point, the second branch road, 3rd branch circuit parallel connection is between the output bus anode and output bus negative terminal of centrally connected power supply supply unit 1.

Circuit connection structure of the present utility model is：It is shown in Figure 2, a kind of HVDC LED constant current circuit, the height Straightening stream LED constant current circuit includes first voltage detection control circuit, LED string I and the first constant-current circuit, the voltage detecting Control circuit includes voltage detecting and controling circuit triode V2, the first divider resistance R1 and the second divider resistance R3, two partial pressures One end of resistance connects voltage detecting and controling circuit triode V2 base stage, the first divider resistance R1 other end connection institute simultaneously State LED string I negative terminal, the negative pole of the second divider resistance R3 other end connection power supply, first voltage detection control circuit three Pole pipe V2 colelctor electrode connects the first constant-current circuit metal-oxide-semiconductor V1 grid, first voltage detection control circuit triode V2 hair Emitter-base bandgap grading connects the negative terminal of the LED string I, and first constant-current circuit includes the first constant-current circuit metal-oxide-semiconductor V1, first limit Leakage resistance R2, a first current sense resistor R4 and one first constant-current circuit triode V3, the first constant-current circuit metal-oxide-semiconductor V1 Drain electrode connect the negative terminal of the first LED string with the first current-limiting resistance R2 one end, the first constant-current circuit metal-oxide-semiconductor V1 source electrode and First current sense resistor R4 one end connects the first constant-current circuit triode V3 base stage, the first current sense resistor R2 simultaneously The other end and the first constant-current circuit triode V3 emitter stage be connected to the negative pole of power supply, the first constant-current circuit metal-oxide-semiconductor V1's Grid connects the first current-limiting resistance R2 other end, first voltage detection control circuit triode V2 colelctor electrode and first simultaneously Constant-current circuit triode V3 colelctor electrode.

To sum up shown, the utility model uses HVDC centrally connected power supply mode power, and power supply output connects LED string and perseverance Current circuit, and every a string of high-voltage LEDs use independent constant-current circuit constant current, and every group of circuit supports PWM light modulations, the circuit Application solve that conventional low LED power supplies and constant-current circuit device cost are high, input power factor is low, power-efficient is low, can The control property problem such as low.

Better embodiment of the present utility model is the foregoing is only, the scope of protection of the utility model is not with above-mentioned reality The mode of applying is limited, as long as equivalent modification that those of ordinary skill in the art are made according to the utility model disclosure or change Change, should all include in the protection domain described in claims.

Claims (3)

1. a kind of HVDC LED constant current circuit, including centrally connected power supply supply unit, multiple LED strings, the pole of multiple constant currents two Pipe, it is characterised in that：Connected on each described LED string a corresponding current regulator diode, the LED string with The current regulator diode forms a branch road, and described branch circuit parallel connection is in the output bus anode of centrally connected power supply supply unit and output Between bus negative terminal.

A kind of 2. HVDC LED constant current circuit according to claim 1, it is characterised in that：The current regulator diode Number is equal with the number of LED string, and the LED number in described each LED string is equal, in the LED string Each LED lamp is high-voltage LED light fixture.

A kind of 3. described HVDC LED constant current circuit according to claim 1, it is characterised in that：The HVDC LED Constant-current circuit includes first voltage detection control circuit, LED string I and the first constant-current circuit, the voltage detecting and controling circuit Including voltage detecting and controling circuit triode V2, the first divider resistance R1 and the second divider resistance R3, the one of two divider resistances End connects voltage detecting and controling circuit triode V2 base stage simultaneously, and the first divider resistance R1 other end connects the LED String I negative terminal, the negative pole of the second divider resistance R3 other end connection power supply, first voltage detection control circuit triode V2's Colelctor electrode connects the first constant-current circuit metal-oxide-semiconductor V1 grid, first voltage detection control circuit triode V2 emitter stage connection The negative terminal of the LED string I, first constant-current circuit include the first constant-current circuit metal-oxide-semiconductor V1, first current-limiting resistance R2, a first current sense resistor R4 and a first constant-current circuit triode V3, the first constant-current circuit metal-oxide-semiconductor V1 drain electrode The negative terminal of the first LED string, the first constant-current circuit metal-oxide-semiconductor V1 source electrode and the first electricity are connected with the first current-limiting resistance R2 one end The one end for flowing detection resistance R4 connects the first constant-current circuit triode V3 base stage simultaneously, and the first current sense resistor R2's is another End and the first constant-current circuit triode V3 emitter stage are connected to the negative pole of power supply, and the first constant-current circuit metal-oxide-semiconductor V1 grid is same When connect the first current-limiting resistance R2 other end, first voltage detection control circuit triode V2 colelctor electrode and the first Constant Electric Current Road triode V3 colelctor electrode.