CN201332522Y

CN201332522Y - LED lighting circuit

Info

Publication number: CN201332522Y
Application number: CNU2008202020512U
Authority: CN
Inventors: 刘东芳
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-10-20
Filing date: 2008-10-20
Publication date: 2009-10-21
Anticipated expiration: 2018-10-20

Abstract

The utility model relates to an LED circuit, in particular to an LED lighting circuit, which comprises a power supply circuit and an LED lighting lamp circuit, wherein the power supply circuit comprises a voltage input end, a power on surge current, an over-current protection circuit, a bridge type rectification circuit, a constant current output circuit and a current output end, wherein LED elements of the LED lighting lamp circuit use matrix type connecting structures which are parallelly connected firstly and then are connected in series. The LED circuit can prevent the influence which is brought by the changes of LED resistance values during the work process, and the LED lighting lamp circuit uses the matrix type connecting structures which are parallelly connected firstly and then are connected in series, when one or more LED break down, the lighting of a whole lamp can not be markedly effected, thereby reducing the maintenance cost of the lamp, and also prolonging the service life of the lamp.

Description

The LED lighting circuit

Technical field

The utility model relates to a kind of led circuit, specifically, relates to a kind of LED lighting circuit.

Background technology

The power circuit of current most of LED lighting circuits adopts capacitance decompression and bridge rectifier to finish jointly, but capacitance decompression is not suitable for dynamic load, is not suitable for capacitive and inductive load etc., because the resistance of LED changes in the course of the work, the nonlinear change along with variation of temperature, so the LED load is not permanent ohmic load, be dynamic load, this requires higher to power circuit, and current power circuit will cause the instability of circuit.

The connection design that also has LED lighting lamp circuit great majority to adopt pure series connection or connection in series-parallel to combine.If adopt pure series circuit design, when one of them LED breaks down, can influence the illumination of whole light fixture; If the connection of adopting connection in series-parallel to combine when one of them LED breaks down, a string LED illumination can occur and break down; The maintenance frequency of light fixture increases like this, and the maintenance cost height can cause a lot of troubles to the client.As Fig. 2, what the LED display element adopted is exactly series-parallel circuit, and when one of them LED in any one series branch broke down, this a string LED illumination all can be broken down so, Fig. 3 is pure series circuit, when wherein any one LED broke down, entire circuit all can be cut off the power supply so, and also pretty troublesome during the inspection fault point of these two circuit, LED checks one by one, maintenance frequency increases, and the maintenance cost height can cause a lot of troubles to the client.

The utility model content

At above deficiency, the utility model provides a kind of LED lighting circuit, and it comprises power circuit and LED lighting lamp circuit.Wherein power circuit comprises voltage input end, start surge current and current foldback circuit, bridge rectifier, electric capacity, constant current output circuit and current output terminal, and the LED display element of LED lighting lamp circuit adopts the matrix form syndeton of series connection more in parallel earlier.

Described start surge current and current foldback circuit comprise F1 fuse and RT1 negative tempperature coefficient thermistor; Described bridge rectifier adopts a bridge rectifier pipe DB1 that alternating current is changed into direct current; Described constant current output circuit comprises U1 constant-current LED chip for driving, resistance R 1, R2, R3, capacitor C 1, C3, diode D1, voltage-stabiliser tube DZ1, power switch pipe Q1 and an inductance L 1.

Advantage of the present utility model:

1, this circuit has overcome the drawback of capacitance decompression, can be applicable to dynamic load, capacitive and inductive load; This control circuit peripheral cell is few, simplicity of design, and cost is low, is applicable to home lighting and indoor decoration with the light fixture of this circuit production.

2, the LED display element of LED lighting lamp circuit adopts the matrix form syndeton of series connection more in parallel earlier, when one of them or several LED break down, can not produce significantly influence to the illumination of whole light fixture, so promptly reduce the maintenance cost of light fixture, prolong the useful life of light fixture again.

Description of drawings

Fig. 1 is a LED lighting circuit schematic diagram;

Fig. 2 is the pure cascaded structure schematic diagram of LED lighting lamp circuit;

Fig. 3 is a LED lighting lamp circuit series parallel structure schematic diagram;

Fig. 4 is circuit construction of electric power figure;

Fig. 5 is the LED lighting lamp circuit structural representation of join-matrix formula more in parallel earlier.

Embodiment

Below in conjunction with accompanying drawing the utility model is further set forth.

As shown in Figure 1, the LED lighting circuit, it comprises power circuit (1) and LED lighting lamp circuit (2).Wherein (1) comprises voltage input end (11), start surge current and current foldback circuit (12), bridge rectifier (13), electric capacity (14), constant current output circuit (15) and current output terminal (16); (2) LED display element adopts the matrix form syndeton of series connection more in parallel earlier.

As shown in Figure 4, start anti-surge current protecting circuit of moment and current foldback circuit comprise F1 fuse and RH1 negative tempperature coefficient thermistor.RT1 (10SP) negative tempperature coefficient thermistor can prevent that immediate current of boot-strap is too high and burn in the circuit other components and parts, F1 (0.5A, 250V) fuse can ensure circuit under normal operation, and the variation of power network current can not exert an influence to the components and parts of circuit.

Bridge rectifier adopts a bridge rectifier pipe DB1 (DF06M), can change alternating current into direct current.

Electric capacity adopts a C2, and (6.8uF 400V), is used to filter the ripple behind the bridge rectifier.

Constant current output circuit comprises U1 constant-current LED chip for driving, resistance R 1, R2, R3, capacitor C 1, C3, diode D1, voltage-stabiliser tube DZ1, power switch pipe Q1 and an inductance L 1:

1) U1 (SMD802) is the constant-current LED chip for driving with PWM function; can normal process ac input end voltage 85V to 265V; the voltage that pin1 (VIN) can bear can reach 500V and have overheat protective function, and the following Constant Current Load of 1A can be realized by U1.

2) R1 (75K, 1/4W) and DZ1 (75V) voltage-stabiliser tube: shield, avoid the impact chip of AC signal frequency.

3) (0.95ohm, 1/4W): inductive current detects resistance to R3.Another important function is when load short circuits, and metal-oxide-semiconductor Q1 electric current sharply increases, and the pressure drop on the R3 raises; when inductive current reference signal that this signal produces greater than chip internal, internal protection circuitry starts, the internal comparator upset; metal-oxide-semiconductor Q1 is ended, inactivity output.

4) fast diode D1 (HER105), capacitor C 1 (2.2uF, 50V), inductance L 1 (10mH, 1A, 0.17X500TS): when the work of Q1 (2N60) power MOS pipe ends, discharge through D1 to the LED electric by L1, C1 plays filter action, and there is constant electric current output at LED+ and LED-two ends.

5) when the conducting of Q1 (2N60) power MOS pipe, L1, Q1, R3 form the loop, and there is constant electric current output at LED+ and LED-two ends.

6) (0.22uF 50V) is filter capacitor to C3, R2 (470K, 1/8W) operating frequency of adjusting U1.

As shown in Figure 5 the LED display element of LED lighting lamp circuit adopt first parallel connection again the join-matrix formula connect and to carry out circuit design, when one of them or several LED break down, can not produce significantly influence to the illumination of whole light fixture, so promptly reduce the maintenance cost of light fixture, prolonged the useful life of light fixture again.

Claims

1, a kind of LED lighting circuit; it comprises power circuit (1) and LED lighting lamp circuit (2); it is characterized in that; described power circuit (1) comprises voltage input end (11), start surge current and current foldback circuit (12), bridge rectifier (13), electric capacity (14), constant current output circuit (15) and current output terminal (16), and the LED display element of described LED lighting lamp circuit (2) adopts the matrix form syndeton of series connection more in parallel earlier.

2, LED lighting circuit according to claim 1 is characterized in that, described start surge current and current foldback circuit (12) comprise F1 fuse and RT1 negative tempperature coefficient thermistor.

3, LED lighting circuit according to claim 1 is characterized in that, described bridge rectifier (13) adopts a bridge rectifier pipe DB1 that alternating current is changed into direct current.

4, LED lighting circuit according to claim 1, it is characterized in that described constant current output circuit (15) comprises U1 constant-current LED chip for driving, resistance R 1, R2, R3, capacitor C 1, C3, diode D1, voltage-stabiliser tube DZ1, power switch pipe Q1 and an inductance L 1.