The LED power circuit
Technical field
The present invention relates to a kind of power circuit, especially relate to a kind of LED power circuit.
Background technology
Existing light fixture comprises incandescent lamp, common fluorescent lamp and LED light fixture etc., common fluorescent lamp is gas-discharge lamp, the photoelectric transformation efficiency of common fluorescent lamp is higher than incandescent lamp, yet common fluorescent lamp requires high to operating ambient temperature, is not easy to start when temperature is low, heat is given birth in argon gas ionization during use in the common fluorescent lamp, thereby make mercury generation steam and send strong ultraviolet ray, common fluorescent lamp easily glimmers, and affects user's eyesight.In addition, when the fluorescent tube of common fluorescent lamp when breaking, the luminescent substance that flows out in it pollutes the environment and the mankind is damaged.
The LED light fixture has the advantages such as energy conversion efficiency is high, on-off effect speed is fast, the life-span long, radiationless and low in energy consumption and is widely used.Existing LED light fixture is provided with the power circuit for driving LED usually, for example number of patent application is 200920293872 to disclose a kind of LED power circuit, it comprises step-down shaping circuit and electric bridge, one end of the front termination AC power of this step-down shaping circuit, an input of the described electric bridge of rear termination of step-down shaping circuit, the other end of another input termination AC power of electric bridge, be serially connected with electrochemical capacitor between the high level output end of electric bridge and the low level output end, these electrochemical capacitor two ends are the low-voltage, high-current output, these electrochemical capacitor two ends and be connected to shunt resistance, the two ends of described electrochemical capacitor are also and be connected to piezo-resistance.Yet, above-mentioned existing LED power circuit poor stability, can not use simultaneously life voltage different the country and regional.
Summary of the invention
The defective that the present invention be directed to the existence of above-mentioned background technology provides a kind of LED power circuit, and this number of circuit elements is few, and the low good stability that reaches of cost can use under the voltages such as 110V or 220V and work, thereby adapt to different countries and regions.
For achieving the above object, the invention discloses a kind of LED power circuit, it comprises reduction voltage circuit, rectification circuit, filter circuit, linear current stabilization circuit, holding circuit and output circuit, described output circuit is provided with cathode output end and cathode output end, and described cathode output end is electrically connected with linear current stabilization circuit; Described cathode output end is electrically connected with the anode of resistance R 14 and switching diode D2, and the negative electrode of described switching diode D2 is electrically connected with holding circuit; The other end of described resistance R 14 is connected with contact B, and described contact B is connected with resistance R 13, and the other end of described resistance R 13 detachably is electrically connected with the contact B of described linear current stabilization circuit; Be used for being connected the first light emitting diode group between described cathode output end and the described contact A; Be used for being connected the second light emitting diode group between described contact B and the described cathode output end; Described holding circuit is provided with triode Q2, and the base stage of described triode Q2, emitter stage and colelctor electrode are electrically connected to respectively negative electrode and the described linear current stabilization circuit of described filter circuit, switching diode D2.
Further, described holding circuit is provided with triode Q2, is connected with two resistance R parallel with one another 9 and resistance R 10 between the base stage of described triode Q2 and the emitter stage, and described emitter stage is connected with the cathodic electricity of described filter circuit and described switching diode D2; Be provided with resistance R parallel with one another 5 and resistance R 6 between described filter circuit and the described base stage, the colelctor electrode of described triode is electrically connected with resistance R 7 and described linear current stabilization circuit, and the other end of described resistance R 7 is electrically connected with described filter circuit.
Further, described linear current stabilization circuit is provided with FET Q1, the drain electrode of described FET Q1 is electrically connected with filter circuit, the grid of described FET Q1 is electrically connected with the colelctor electrode of described triode, the source electrode of described FET is connected with resistance R 8 and resistance R 11, described resistance R 8 links to each other with the anode of described cathode output end and Zener diode ZD1, and the other end of described Zener diode ZD1 links to each other with described colelctor electrode; The other end of described resistance R 11 is electrically connected with the anode of described contact A and Zener diode ZD2, and the negative electrode of this Zener diode ZD2 is electrically connected with described colelctor electrode.
Further, described reduction voltage circuit is provided with capacitor C 1 and the capacitor C 2 of some Anti-surge resistors parallel with one another and mutually series connection, be connected with an end of a capacitor C 5 between described capacitor C 1 and the described some Anti-surge resistors, the other end of described capacitor C 5 is electrically connected with an end of described capacitor C 2.
Further, described capacitor C 1, capacitor C 2 and capacitor C 3 are high pressure laminating electric capacity.
Further, described rectification circuit is the MD4S bridge rectifier.
Further, described filter circuit is two mutually capacitor C 3 and the capacitor C 4 of series connection.
In sum, LED power circuit of the present invention is by the cooperation of described each components and parts, when at household electricity being the high-tension country such as 220V, can directly provide required electric energy for described light emitting diode group; When being the low-voltage such as 110V national at household electricity, directly described resistance R 13 is taken out and get final product, thereby realization can using and work under the voltages such as 110V or 220V, thereby adapt to different countries and regions.In addition, this number of circuit elements is few, the low good stability that reaches of cost.
Description of drawings
Fig. 1 is the theory diagram of an embodiment of the present invention;
Fig. 2 is circuit diagram of the present invention shown in Figure 1;
Fig. 3 is the circuit diagram of the present invention shown in Figure 2 when being connected with LED.
The specific embodiment
For further understanding feature of the present invention, technological means and the specific purposes that reach, function, below in conjunction with accompanying drawing and the specific embodiment the present invention is described in further detail.
See also Fig. 1 to Fig. 3, LED power circuit of the present invention comprises reduction voltage circuit 1, rectification circuit 2, filter circuit 3, linear current stabilization circuit 4, holding circuit 5 and output circuit 6.Described reduction voltage circuit 1 is high pressure laminating capacity voltage dropping circuit 1, and it is provided with capacitor C 1 and the capacitor C 2 of some Anti-surge resistors parallel with one another and mutually series connection, described Anti-surge resistor be resistance R 1 to resistance R 4, the one end is used for linking to each other with live wire.Be connected with an end of a capacitor C 5 between described capacitor C 1 and the described some Anti-surge resistors, the other end of described capacitor C 5 is electrically connected with an end of described capacitor C 2.In the present embodiment, described capacitor C 1, capacitor C 2 and capacitor C 3 are high pressure laminating electric capacity, thereby can strengthen service life of the present invention, and element is few, and cost is low.
In the present embodiment, described rectification circuit 2 is the MD4S bridge rectifier, and described MD4S bridge rectifier is electrically connected with zero line and described capacitor C 2.Described filter circuit 3 is two mutually capacitor C 3 and the capacitor C 4 of series connection, and described capacitor C 3 is electrically connected with the positive voltage output end of described MD4S bridge rectifier, and described capacitor C 4 is electrically connected with the negative voltage output of described MD4S bridge rectifier.
Described holding circuit 5 is provided with triode Q2, is connected with two resistance R parallel with one another 9 and resistance R 10 between the base stage of described triode Q2 and the emitter stage.Described emitter stage is connected with the capacitor C 4 of described filter circuit 3 and the cathodic electricity of described switching diode D2.Be provided with resistance R parallel with one another 5 and resistance R 6 between described filter circuit 3 and the described base stage, the colelctor electrode of described triode is electrically connected with resistance R 7 and described linear current stabilization circuit 4, and the other end of described resistance R 7 is electrically connected with described filter circuit 3.The size of the resistance value by changing resistance R 5, resistance R 6 and R9 and resistance and R10, thereby the voltage protection point that setting is complementary for different AC voltage.
Described linear current stabilization circuit 4 is provided with FET Q1, and the drain electrode of described FET Q1 is electrically connected with filter circuit 3, and the grid of described FET Q1 is electrically connected with the colelctor electrode of described triode.The source electrode of described FET Q1 is connected with resistance R 8 and resistance R 11, and described resistance R 8 links to each other with the anode of described cathode output end LED+ and Zener diode ZD1, and the other end of described Zener diode ZD1 links to each other with described colelctor electrode.The other end of described resistance R 11 is electrically connected with the anode of described contact A and Zener diode ZD2, and the negative electrode of this Zener diode ZD2 is electrically connected with described colelctor electrode.Described linear current stabilization circuit 4 has improved the stability of described reduction voltage circuit 1 electric current, so that circuit adaptability is higher.
Described output circuit 6 is provided with cathode output end LED+ and cathode output end LED-, and described cathode output end LED+ is electrically connected with linear current stabilization circuit 4.Described cathode output end LED-is electrically connected with the anode of resistance R 14 and switching diode D2, and the negative electrode of described switching diode D2 is electrically connected with holding circuit 5.The other end of described resistance R 14 is connected with contact B, and described contact B is connected with resistance R 13, and the other end of described resistance R 13 detachably is electrically connected with the contact B of described linear current stabilization circuit 4.Be used between described cathode output end LED+ and the described contact A being connected the first light emitting diode group, described the first light emitting diode group is provided with the light emitting diode from LED1A to LED30A of mutual series connection.Be used between described contact B and the described cathode output end LED-being connected the second light emitting diode group, described the second light emitting diode group is provided with the light emitting diode from LED31A to LED60A of mutual series connection.
In sum, LED power circuit of the present invention is by the cooperation of described each components and parts, when at household electricity being the high-tension country such as 220V, can directly provide required electric energy for described light emitting diode group; When being the low-voltage such as 110V national at household electricity, directly described resistance R 13 is taken out and get final product, thereby realization can using and work under the voltages such as 110V or 220V, thereby adapt to different countries and regions.In addition, this number of circuit elements is few, the low good stability that reaches of cost.
The above embodiment has only expressed one embodiment of the present invention, and it describes comparatively concrete and detailed, but can not therefore be interpreted as limitation of the scope of the invention.Should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with claims.