LED Lighting Design

Dec 25, 2019

LED lamps in the optical system design, electrical accessories, heat dissipation measures and structure design and other aspects of the traditional light source compared to the lamp is obvious.

A) optical systems The optical system of the luminaire is the soul of the luminaire, the purpose of which is to design a luminaire optical system that meets the specific lighting requirements according to the characteristics of the selected light source. Usually the optical system of conventional light source lamps consists of light source, lamp holder, Reflector and transmittance hood. Because some led units have the luminosity characteristics of 2π luminescence, the photometric system of lamps is very different from that of traditional light source lamps.

The specific performance characteristics are as follows: (1) LED Luminaire optical system is generally composed of LED chips and lenses composed of LED units or led unit arrays, arrays are sometimes arranged on a flat aluminum substrate, may also be on the protruding or concave molding substrate, lamps use, or do not use a transmittance cover.

Lighting manufacturers can be based on lighting needs, a number of LED units or dozens of LED units combined on the substrate, should pay attention to control the combination of LED unit light color consistency, assessment LED lamps color space uniformity. (2) because the photoelectric characteristics of the LED is very sensitive to the change of PN junction temperature, the packaging resin will be rapidly degraded under high temperature and strong light irradiation, long-term light radiation will gradually reduce the photoluminescence rate of phosphor, and lead to label will offset of the color seat.

The life evaluation of LED lamps is usually under the condition of limiting color offset, the lumen maintenance rate of LED lamps is assessed.

b) Electrical Accessories LED Drive power supply is the key factor that constitutes the performance of LED luminaire, and it is also one of the selection or design elements of luminaire.

LED Luminaire Electrical design should consider the luminaire to use led characteristics and quantity, the installation location of the luminaire, as well as the location of the luminaire in the power grid to consider electrical safety, constant current drive, immunity and EMI, select or design a suitable led drive power supply. Because LEDs are 2v~3v low voltage constant current source drive, it is not like ordinary incandescent bulbs can be directly connected to 220V of AC power,

The power supply and control circuit must be designed to drive the LED. In addition, the electrical connection of the LED module is also an important part of the LED Luminaire electrical system, should take full account of the safety, should be used standard connectors, adequate insulation, anti-electric shock protection and so on.

c) Thermal measures Like traditional light source lamps, LED luminaires will also be hot, led luminaire heat from the LED photoelectric conversion in the loss and led drive power supply. Unlike the traditional luminous light source luminescence principle (thermal radiation of incandescent lamps and fluorescent lamps, etc.), led luminescence is electroluminescent, due to the problem of conversion efficiency, most of the output energy is mainly in the form of non-radiation composite dot-matrix vibration conversion of heat energy. And the way heat is transmitted inside the LED is not radiation but conduction.

Therefore, the main goal in the LED luminaire cooling design is to effectively transmit the heat of the LED chip effectively, and effectively control the LED luminaire in the LED junction temperature. For LED lamps, in addition to LED is a heating component, LED lamps in the drive is also a heating component, in order to ensure that with the LED light source coordination of the life, led driver thermal control is also very important, if the use of internal drive power supply, lamps should be selected according to its ambient temperature of the corresponding TC drive.

When the drive is installed independently, the corresponding TC drive should be selected according to the possible ambient temperature of the installation.

d) Mechanical components and structures

The function of the machine is to determine the position and correlation of the optical system, electrical system and thermal system of the luminaire through structural design, so that the luminaire can be fixed and used safely in the set environment. The mechanical system of traditional lamps is composed of fixed light source, reflector, lamp control device and other parts structure, soft cable or soft wire wiring structure, sealing structure, mechanical protection structure, luminaire fixed structure and luminaire adjustment structure, etc., specifically by the lamp holder or light source connector, lamp holder mounting bracket, soft wire holder, terminal seat, Shell, The lampshade and luminaire mounting frame are composed of the lamp. Because of the characteristics of LED light source, LED lamps have packaging, modules, LED light engine, integral LED lights, non-integral LED lights and other forms, in addition to the last two forms may have similar to the traditional light source lamps outside the internal structure, other LED lamps do not have a standard lamp head, in this case,

LED luminaires have the following structural characteristics:

There is no lamp holder in the-led luminaire, but the electrical connection between the LED lamp and the luminaire is completed with the connector, and the LED lamp is fixed to the main body of the luminaire by other means. -In order to export the heat generated by the LED chip, the LED luminaire has a large number of heat sink, the volume and weight of the luminaire is much larger than the traditional light source luminaire, the installation structure of the luminaire should be considered accordingly to ensure the safety and reliability of the installation.

At the same time, the heatsink should be designed to be easy to clean or not easy to accumulate ash structure, otherwise, the efficiency of the heat sink will be reduced quickly.

-When the LED luminaire uses a power cord, and the power cord is removable for maintenance, it belongs to a non-Z-type connection, like the traditional light source connected by a non-Z-type, LED lamps should also use a soft wire fixing frame.