CN201274590Y

CN201274590Y - LED driving apparatus using commercial power

Info

Publication number: CN201274590Y
Application number: CNU2008201350869U
Authority: CN
Inventors: 田承仁; 李纯廉
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-08-29
Filing date: 2008-08-29
Publication date: 2009-07-15
Anticipated expiration: 2018-08-29

Abstract

The utility model relates to a commercial power LED driving device, which comprises a rectifying circuit, a voltage detection circuit, a switch circuit, an energy storage circuit and a low voltage LED driving circuit, wherein, the voltage detection circuit detects the output of the rectifying circuit; when the output is lower than the pre-determined value, a control signal is outputted to control the on of the switch circuit, and the output of the rectifying circuit is allowed to supply power to the low voltage LED driving circuit through the energy storage circuit. The switch tube is alternatively opened according to the voltage of the commercial power, so that the outputted voltage can be controlled, thereby reducing the on-off stress of the switch transistor, and improving the reliability; at the same time, the heavy high voltage rectifying capacitor, inductance or transformer are saved, thereby reducing the electromagnetic interference while reducing the cost.

Description

The commercial LED drive unit

Technical field

The utility model relates to a kind of commercial LED drive unit.

Background technology

Energy savings is the sustainable development Eternal Theme.Along with LED (is a light-emitting diode, being commonly called as of semiconductor lighting, the abbreviation of Light Emitter Diode) in urban look, commercial large-screen, traffic lights, the extensive application of special dimensions such as new automobile, its full coloured light, unlimited colour mixture, remarkable spectral performance, switch rapidly, shatter-proof, moisture resistance, cold temperature, the overlength longevity, advantage such as non-maintaining, it is the most popular to have become the whole world, the light source of attracting attention most, simultaneously along with the improving constantly of LED luminous efficiency, semiconductor lighting has been considered to 21 century and has entered one of a kind of novel solid-state cold light source in general lighting field and high frontier of tool development prospect.

But in the LED lighting field, same fluorescent lamp, tungsten halogen lamp are the same, large power white light LED energy-conservation except the electro-optical efficiency factor that is embodied in LED self, and also to be converted into the efficient that is fit to the electric current and voltage that white light LEDs uses closely related with civil power.Because the current drives characteristic of LED, product on the market is when utilizing civil power to drive the large power white light LED product at present, indirect type of drive of working voltage conversion all, promptly adopt AC-DC converter circuit to convert interchange to direct current after, luminous to white light LEDs supply direct current again.The domestic transformer that generally all uses changes to low-voltage direct with 220V, and then (single tube is generally 3.2～4V) to be converted to the required voltage of white light LEDs, this has wherein just had extra power loss when high efficiency (even also have 10%～20%), if count the conversion efficiency that dc low-voltage drives white light LEDs again, then power loss is bigger.

The utility model content

The utility model has overcome above-mentioned defective, and the commercial LED drive unit of a kind of whole utilization rate of electrical height, dependable performance is provided.

The technical scheme in the invention for solving the technical problem is: a kind of commercial LED drive unit, comprise the rectification circuit, voltage detecting circuit, switching circuit, accumulator and the low-voltage LED drive circuit that connect successively, described voltage detecting circuit detects the output of described rectification circuit, the control signal of when being lower than set point, exporting, control described switching circuit and open, the output that allows described rectification circuit by described accumulator to the low-voltage LED drive circuitry.

Described switching circuit can comprise power switch driver circuit and power field effect pipe, the drain electrode of described power field effect pipe and source series are between described rectification circuit and accumulator, grid links to each other with described power switch driver circuit, the control signal of described voltage detecting circuit output, control the grid that described power switch driver circuit drives described power field effect pipe, and then control described power field effect pipe and open.

The input of described rectification circuit also can be connected with protective circuit.

Described voltage detecting circuit can comprise the voltage comparator that is made of amplifier and resistance, the reverse input end of described amplifier is connected to the output of described rectification circuit, input is connected between two series resistances in the same way, and output links to each other with described power switch driver circuit.

Described two series resistances that link to each other with the input in the same way of amplifier can comprise variable resistor.

Described voltage detecting circuit and power switch driver circuit can be integrated in the half-bridge gate driver that model is L6393.

Described accumulator can comprise electrochemical capacitor, and the positive terminal of described electrochemical capacitor is connected between described switching circuit and the low-voltage LED drive circuit, negative pole end ground connection.

The model of described low-voltage LED drive circuit can be LT3474-1.

The utility model is opened switching tube selectively according to the voltage of civil power, make output voltage to control, reduced the switch stress of switching transistor, improved its reliability, the high-voltage rectifying electric capacity, inductance or the transformer that have saved the volume heaviness simultaneously, thereby when reducing cost, also reduced electromagnetic interference.The utility model has solved the problem of civil power high efficiency drive low-voltage LED, from the direct high efficiency drive large power white light LED of civil power (220VAC or 110VAC), do not need transformer that interchange is become direct current and drive white light LEDs again, compare with product in the market, the power loss that had not both had transducer to cause, cost and volume have also been reduced, this drive unit volume is small and exquisite, with low cost, dependable performance, whole utilization rate of electrical height can strengthen the service efficiency of LED itself, effectively improve its useful life, reach the life-span of itself designing.The utility model can solve and drive the problem of 1W to the LED of 200W, thereby satisfies the application demand of domestic public illumination markets such as industrial and mining enterprises, room lighting, road lighting to the LED illumination.

Description of drawings

Fig. 1 is circuit theory diagrams of the present utility model.

Embodiment

As shown in fig. 1, comprise protective circuit U4, rectification circuit U1, voltage detecting circuit, switching circuit, accumulator and the low-voltage LED drive circuit U3 that connects successively.

Described protective circuit U4 adopts devices such as protective tube, NTC resistance, safety electric capacity; interference spurious signal in the electric main that filtering directly inserts; and device played overload protective function, because above-mentioned protection device all belongs to routine techniques, repeat no more here.The optional withstand voltage 600V of described rectification circuit U1, the rectifier bridge of maximum operating currenbt 2A.

Described switching circuit comprises power switch driver circuit U2 and power field effect pipe Q (being called for short switching tube Q), the MOSFET pipe of the optional withstand voltage 600V of described power field effect pipe, as IPB60R099, the drain electrode of described power field effect pipe Q and source series are between described rectification circuit and accumulator, and grid links to each other with described power switch driver circuit U2.Described voltage detecting circuit is by amplifier AR and resistance R 1, the voltage comparator that R2 constitutes constitutes, the reverse input end of described amplifier AR is connected to the output of described rectification circuit U1, from the output of described rectification circuit, sample, input is connected between two series resistances in the same way, obtain the reference voltage between two series resistances, the output of described amplifier AR links to each other with the control input end of described power switch driver circuit U2, when the voltage of the reverse input end of described voltage comparator input is lower than in the same way input terminal voltage, the output output high level of power amplifier AR, described power switch driver circuit U2 is after receiving this high level signal, drive the grid of described power field effect pipe Q, and then control described power field effect pipe Q conducting.Described power switch driver circuit U2 can adopt the high-end MOSFET chip for driving of high pressure, perhaps is integrated in the half-bridge gate driver that model is L6393 with described voltage detecting circuit.

Described accumulator comprises electrochemical capacitor C, and the positive terminal of described electrochemical capacitor C is connected between described power field effect pipe Q and the low-voltage LED drive circuit U3, and negative pole end ground connection is if maximum output is set in 30V, the then electrochemical capacitor of optional 50V.

Described low-voltage LED drive circuit has the ripe chip of numerous companies available, and as Linear, Maxim, companies such as Nationa1, Zetex adopt the LT3474-1 of Linear company in the present embodiment.The LED that connects by the output driving of described low-voltage LED drive circuit U3 is the luminous work of D1, D2.

Based on the foregoing circuit structure; electric main is through protective circuit U4; and by after the rectification circuit U1 conversion; the high-pressure pulsating direct voltage of output is loaded on the switching tube Q; described voltage detecting circuit monitoring high-pressure pulsating direct voltage when the high-pressure pulsating direct voltage is lower than set point (being the reference voltage that forms between resistance R 1, the R2), sends high level signal and passes through power switch driver circuit; open switching tube Q, power to storage capacitor C.Adopt variable resistors with any or two among two series resistance R1, the R2 that the input in the same way of described amplifier links to each other, by regulating described variable-resistance resistance, can regulate described set point according to demand, as long as be no more than the maximum working voltage of low-voltage LED chip for driving, thereby satisfy the power supply needs of different LED loads, like this in the whole operating time, voltage on the capacitor C is all lower, thereby can use many very ripe low-voltage LED chip for driving to drive great power LED in the rear end, need not to adopt expensive commercial LED special driving chip.

The utility model is by detecting the mode control switch pipe Q of Output Voltage in Rectified Circuits, make switching tube always in certain low voltage range, open, the output voltage that makes switching tube is always in the input voltage range of low-voltage LED drive circuit, and can adjust as required, thereby can use the low-voltage LED driver of a lot of maturations, saved the big electric capacity of bulky high pressure simultaneously, big inductance or transformer, only use less resistance, electric capacity, discrete element such as switching tube, described capacitor C can be used cheapness simultaneously, the low-voltage capacitance of small size, reduce cost, reduced electromagnetic interference.And owing to switching frequency in the course of work is lower, the power consumption that makes power open the light on the pipe is very low, thereby can use low power transistor, also reduce when reducing cost, improve efficient the requirement of power switch driver circuit and the power consumption of itself.

Adopt drive unit of the present utility model, with low cost, dependable performance, structure is small and exquisite, do not need heat radiation, the efficient height, die stress is little, the LED drive unit that civil power can be driven 2W is accomplished can be put into fully in the existing lamp holder on the circuit board of a 2cm * 2cm size, can be widely used in city's electric lighting and industrial and mineral, enterprise, in the extensive electric consumption on lighting such as public places such as road, its distinct advantages is that the LED current/voltage is remained on constant current value substantially, thereby effectively prolongs the useful life of LED.Avoided driving power instability in the like product, LED weak point in useful life and the low problem of luminous efficiency.

More than commercial LED drive unit provided by the utility model is described in detail, used specific case herein principle of the present utility model and execution mode are set forth, the explanation of above embodiment just is used for helping to understand method of the present utility model and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present utility model, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as restriction of the present utility model.

Claims

1. commercial LED drive unit, it is characterized in that: comprise the rectification circuit, voltage detecting circuit, switching circuit, accumulator and the low-voltage LED drive circuit that connect successively, described voltage detecting circuit detects the output of described rectification circuit, the control signal of when being lower than set point, exporting, control described switching circuit and open, the output that allows described rectification circuit by described accumulator to the low-voltage LED drive circuitry.

2. commercial LED drive unit according to claim 1, it is characterized in that: described switching circuit comprises power switch driver circuit and power field effect pipe, the drain electrode of described power field effect pipe and source series are between described rectification circuit and accumulator, grid links to each other with described power switch driver circuit, the control signal of described voltage detecting circuit output, control the grid that described power switch driver circuit drives described power field effect pipe, and then control described power field effect pipe and open.

3. commercial LED drive unit according to claim 2, it is characterized in that: described voltage detecting circuit comprises the voltage comparator that is made of amplifier and resistance, the reverse input end of described amplifier is connected to the output of described rectification circuit, input is connected between two series resistances in the same way, and output links to each other with described power switch driver circuit.

4. commercial LED drive unit according to claim 3 is characterized in that: described two series resistances that link to each other with the input in the same way of described amplifier comprise variable resistor.

5. commercial LED drive unit according to claim 2 is characterized in that: described voltage detecting circuit and power switch driver circuit are integrated in the half-bridge gate driver that model is L6393.

6. according to each described commercial LED drive unit in the claim 1～5, it is characterized in that: the input of described rectification circuit also is connected with protective circuit.

7. according to each described commercial LED drive unit in the claim 1～5, it is characterized in that: described accumulator comprises electrochemical capacitor, and the positive terminal of described electrochemical capacitor is connected between described switching circuit and the low-voltage LED drive circuit, negative pole end ground connection.

8. according to each described commercial LED drive unit in the claim 1～5, it is characterized in that: the model of described low-voltage LED drive circuit is LT3474-1.