Solar LED lighting lamps and lanterns design considerations

With the wide application of LED lighting, LED lighting lamps and lanterns design should accord with our country promulgated the latest outdoor lighting lamps and lanterns of technical specifications, and the standard of city road lighting design. Below to introduce LED lighting lamps and lanterns design matters that should be paid attention to.

a, work environment, LED outdoor lighting lamps and lanterns is due to the working environment is poor, the wind blowing rain the sun, the sun ultraviolet radiation, temperature difference between day and night change, the dust in the air, chemical gas conditions, such as lamps and lanterns is year after year by the nature of aging treatment. Design should fully consider the impact of these factors.

2, LED lamps and lanterns of material and the cooling way choose

enclosure and radiator design as a whole, is used to solve the problem of LED of fever, this way is better, generally choose aluminum or aluminum alloy, copper or copper alloys, and good thermal conductivity of other alloys. The cooling air convection radiator, wind cooling heat dissipation and heat pipe heat dissipation. （ Jet cooling heat dissipation is a kind of similar to the heat pipe radiator, but the structure is more complicated. ）

to choose what kind of operating mode, has a direct impact on the cost of lamps and lanterns, should be considered, and select the best scheme of form a complete set of product design.

the design selection of the lampshade is also vital, currently use a transparent organic glass, PC material, such as traditional chimney is transparent glass products, whether to choose what kind of materials of chimney associated with design of the product positioning, in general, the chimney of outdoor lamps and lanterns is best is one of the traditional glass products, it is long life, make the best choice for high-grade lamps and lanterns. Use transparent material such as plastic, organic glass chimney, the chimney of indoor lamps and lanterns is good, used for outdoor life is limited, because outdoor sunlight, ultraviolet rays, dust, chemical gas chimney aging, the change in the temperature difference between day and night life cut short, and the second is the pollution is not easy to dry clean, reduce chimney transparency affect the light output.

3, LED chips encapsulation

the current domestic production of LED lamps and lanterns, Mainly lamps) Are using more than 1 w leds in series, in parallel to assemble, this method is of high thermal resistance is relatively advanced packaging technology products, it is not easy to build a high quality of lamps and lanterns. Or it is 30 w, 50 w and even larger modules assembled, to achieve the required power, these LED encapsulation materials useful epoxy resin encapsulation, useful silica gel encapsulation. Is the difference between the two: epoxy resin encapsulation heat resistance is poorer, time is long aging. Silica gel encapsulation, good heat resistance, when using, should pay attention to choose.

the general view is: the more chips and radiator whole package is better, or more than the aluminum substrate chip packaging by phase change materials or heat dissipation silicon grease and radiator are connected, the thermal resistance than with the LED device assembly product is smaller than the thermal resistance of thermal resistance, one to two way more conducive to heat dissipation. Use the lamps and lanterns of LED module, module substrate is commonly copper substrate, its connection with external radiator to use phase change materials is good, or good heat dissipation silicon grease, can guarantee the copper substrate heat in a timely manner to the radiator, if processes is not good, easy to make heat accumulation caused by module chip temperature rise too high, the normal operation of LED chip. The author thinks that: more chip packages suitable for general illumination lamps and lanterns, module encapsulation for space limited manufacturing compact led lamps and lanterns, If the head of the main car lighting lamp, etc. ) 。 Four, the design of the radiator

the radiator is one of the led lamps and lanterns is the key component, its shape, size, the cooling surface area should be designed to contact to the benefits, the radiator is too small, the led working temperature is too high, affecting the luminous efficiency and life span, the radiator is too big, consumption materials more to increase the product cost and weight, make the product competitive power. Design suitable led lamp radiator is crucial. The design of the radiator has the following several parts:

1. Clear LED lights need cooling power.

　　2. Design the radiator with some parameters: metal specific heat, coefficient of thermal conductivity of metal, the chip thermal resistance, heat sink thermal resistance and ambient air thermal resistance, etc.

　　3. Determination by the type of cooling, Natural convection, wind cooling, heat pipe cooling, and other ways of cooling heat dissipation. ） From the cost comparison: natural convection cooling cost minimum, wind cooling medium, heat pipe radiator construction cost is higher, the jet refrigeration highest cost.

　　4. The highest working temperature determine the LED lamps and lanterns license ( The environment temperature and temperature rise of the lamps and lanterns of licensing) ，

　　5. Calculate the volume of the radiator, heat dissipation area. And to determine the shape of the radiator.

　　6. Synthesize the radiator and the LED headlamp unit complete lamps and lanterns, and electricity work eight hours, at room temperature is 39 ℃ - - - - - - - 40 ℃ environment to check the temperature of lamps and lanterns, look to whether meet the cooling requirement, to test calculation is correct, if not meet the conditions of use, will recalculate and adjust the parameters.

　　7. Radiator with the seal of the lampshade to do waterproof, dustproof, chimney and the radiator to anti-aging rubber mat or silicone rubber MATS, with stainless steel bolts, sealed waterproof, dustproof.

( Edit: Liu Li)