LED, a light-emitting diode made of semiconductor materials, has made a major breakthrough in technology in recent years. The luminous efficiency of white light-emitting tubes has reached the level of fluorescent lamps, and will reach the level of sodium lamps in 2008. Semiconductor light source energy saving, long life, safety, environmental protection, flicker resistance, variety of colors, convenient control and many other advantages, will replace the traditional light source to trigger another revolution in the lighting industry. Due to light efficiency and cost reasons, semiconductor light sources are currently unable to compete with traditional high-efficiency light sources in large-area white floodlighting, but have traditional light sources in low-power lighting, local lighting, safety lighting, flashing lighting, color lighting, etc. Difficult to compare advantages. Street lamps are mainly used to illuminate the road surface and belong to local lighting. The reason why the semiconductor light source is suitable for local illumination is that the LED is a point source, and the illumination angle is easy to control. In the production, it can also be made into products with various illumination angles, and the optical path can be further conditioned by the mirror light method. By using a specific wide-angle light source for local illumination, the light emitted by the light source can be more effectively utilized. Compared with a light source that is inconvenient to control the illumination angle, a relatively small power can be used to achieve a desired local illumination effect, thereby achieving energy saving. To this end, many companies have made useful explorations to make semiconductor street lamps gradually practical. However, from the recent exhibitions on lighting, many LED lights displayed by enterprises have not considered and utilized the characteristics of LEDs. The street lamps that have been made are only lighted up, and there is no way to talk about lighting effects and energy saving effects. To this end, this paper introduces the structural characteristics and implementation schemes of semiconductor street lamps with a 90-watt semiconductor street lamp as an example, for reference by relevant enterprises when developing products. Do the basic idea of ​​semiconductor street lamps: To do LED street lights, we must first consider the scope of illumination. Street lights require road lighting effects. The air and roadside airspace is not a task of street lights. Therefore, it is necessary to use a combination of a plurality of angles of the light-emitting tube or a mirror to effectively control the distribution of the light, so that the light emitted from the light-emitting tube becomes a long strip of light spreading along the road surface. It has been proved that the semiconductor thus produced The power of about 90 watts of street lamps can exceed the lighting effect of the 250 watt lamp on the road surface, and the energy saving effect is remarkable. To do a good job of semiconductor street lamps, we must first choose a suitable light-emitting tube. In general, semiconductor street lamps can be either low-power LEDs or high-power LEDs. However, practice has proved that although the low-power LED has the advantage of low cost of the light-emitting device, its light decay is faster than that of the high-power light-emitting tube, and the number of tubes used is too large, the assembly is troublesome, and comprehensive consideration is made to select a high-power light-emitting tube. More reasonable. From the current technical level of high-power luminous tubes, the luminous efficiency of 1 watt tube is relatively high, and the energy saving advantage for lighting is obvious. Compared with the 1 watt luminous tube, the luminous efficiency of the 3 watt luminous tube is lower than 1 watt tube, and the price advantage under the same luminous flux is not obvious. It is more reasonable to use the 1 watt tube as the street light source. Semiconductor light sources have their own characteristics in terms of structure and optical characteristics. Therefore, semiconductor street lamps should be designed according to these characteristics. It is not possible to replace semiconductor lamps with traditional lamps. The problem to be solved in the design of the semiconductor street lamp structure is the external shape of the lamp body, the installation of the light-emitting tube, the adjustment of the illumination range, the heat dissipation of the light-emitting tube, and the sealing of the lamp body. At the same time, the designed lamp body structure is also conducive to mass industrial production. The installation of the light-emitting tube with a one-watt light-emitting tube is relatively simple. If the selected driver is an isolated structure, the base and the core of the light-emitting tube are also insulated, as long as the light-emitting tube is fixed on the heat sink. However, if a driver that does not have an isolated structure is used, the insulation treatment between the light-emitting tube and the heat sink is strict, and a certain safety standard must be achieved. Insulation and heat conduction are often contradictory, and good insulation structures tend to be detrimental to heat dissipation. Therefore, it is recommended to use an isolated driver to drive the LED. The adjustment of the illumination range is an important part of the semiconductor lamp. In order to effectively use the light, the advantage of the illumination direction of the light-emitting tube should be exerted to facilitate the regulation, so that the light emitted by the light-emitting tube forms a light strip on the road surface, and does not scatter in the invalid direction. To do this, the simplest method is to use a combination of a variety of angles of the light-emitting tube, or use a mirror, lens to control the angle of illumination, taking into account different exposure distances. For example, three kinds of light-emitting tube combinations with illumination angles of 60 degrees, 30 degrees, and 15 degrees are used to illuminate the illumination of nearby, medium, and long-distance road surfaces, so that the light output from the light-emitting tube uniformly covers half between the two lamps. From the road surface, the coverage width is basically the same as the road width, so that the road can be effectively illuminated with relatively small power. Make it the best lighting effect. To achieve such illumination, the installation angle of the LED must be reasonable. The heat dissipation of the LED is a problem that the semiconductor lamp should focus on. The luminous tube is a cold light source, which does not produce a hot high temperature like an incandescent lamp. However, the temperature resistance of the luminous tube itself is relatively poor, so the heat generated by the operation of the luminous tube must be effectively dissipated into the air to ensure that the luminous tube works. At a safe temperature, such a semiconductor lamp can truly demonstrate the advantages of long life. Both the illuminating tube dies and the white light emitting tube coated phosphors are produced under high temperature conditions of several hundred degrees, and have a certain temperature resistance. However, there is a thermal resistance between the envelope of the light-emitting tube and the die. This thermal resistance causes a temperature difference between the package and the die when the light-emitting tube is in use, and the temperature of the die is higher than the temperature of the case. At present, the material of the external packaging of the luminous tube is mainly an organic material, and is easily deteriorated at a high temperature. This will affect the light transmission of the light-emitting tube, thus reducing the external light effect of the light-emitting tube. In order not to lower the luminous efficiency of the light-emitting tube, the heat generated by the use of the light-emitting tube is dissipated. But to what extent? What is the relationship between the temperature of the heat sink and the temperature of the LED tube? This is a problem that must be understood. Due to the advancement of the production technology of the light-emitting tube, the thermal resistance inside the high-power light-emitting tube is getting lower and lower. At present, the thermal resistance of the one-watt light-emitting tube is generally below 15 degrees/W, that is, adding 1 to the one-watt light-emitting tube. The electrical power of the watt, the die is only 15 degrees higher than the temperature of the shell. According to the current temperature resistance level of the LED tube core material, the temperature of the tube core does not exceed 150 degrees for long-term safe operation. In this way, the case temperature can be safely used at 135 degrees. However, due to the limitation of the package material of the outer casing, the temperature of the shell in actual use is preferably not more than 70 degrees, so that the temperature of the core is only 85 degrees, and the transparent packaging material of the arc tube does not deteriorate rapidly. There is no problem with long-term stable work. Therefore, it is not necessary to lower the temperature of the semiconductor lamp during operation, but it is necessary to reduce the thermal resistance between the arc tube casing and the lamp body casing, so that stable operation can be produced with a relatively small volume and relatively low cost. Semiconductor lamp. The size of the semiconductor street lamp body is relatively large. Therefore, an effective method of dissipating heat is to fully utilize the outer casing of the lamp body to achieve heat dissipation. To do this, firstly, the heat generated by the arc tube can be smoothly conducted to the outer casing, and then the outer casing should have sufficient area and air contact for effective heat exchange. The problem is, how to reasonably transfer the heat generated by the light-emitting tube to the outer casing, how to effectively increase the contact surface of the outer casing and the air, and facilitate the flow of air on the surface of the outer casing, which is a problem to be solved in the thermal structure design of the lamp body. . The comprehensive irradiation range is reasonable, the light utilization rate is high, which is conducive to heat dissipation, and the structure is simple and convenient for mass production. An aluminum alloy die-casting lamp with a curved structure is designed as a street lamp body. In this structure, 30 tubes of 60 degrees, 30 degrees, and 15 degrees 1 watts are used, and 15 sets of the same angle tube are mounted on an aluminum-based circuit board in a strip structure, and the strip-shaped structure light-emitting tube is divided into 6 groups, three groups of left and right are used for illumination of the left and right road surfaces respectively. The 60-degree tube illuminates the near-surface pavement within 10 meters, the 30-degree tube illuminates the mid-area pavement within 18 meters, and the 15-degree tube illuminates the far-field pavement within 25 meters. The circuit board strips equipped with these three kinds of light-emitting tubes are installed on the inclined surface of the lower angle of the three aluminum alloy profiles, and the upper part of the profile is connected with the heat-dissipating fixed board, so that the heat dissipation problem is solved and a reasonable installation angle of the light-emitting tube is ensured. The structure is simple, the aluminum material is used less, the production cost is low, and the lamp body is light. The lamp body is formed by one-time aluminum alloy die-casting method, and the upper part has a heat sink, and the whole body maintains an arc structure to avoid dust accumulation. Driver selection is another important part of making semiconductor lamps. The role of the driver is to turn the unstable AC voltage of the mains into a stable DC current to drive the LED. In order to make the connection simple, the current balance is good, and the driver can drive multiple light-emitting tubes in series. Commonly used drives have two types of structures that are not isolated from the mains and are also isolated from the mains. From the perspective of simple structure and low cost, the non-isolated driver can be selected, but the biggest danger in the use of non-isolated driver is that the large current will pass through all the luminous tubes when the driver has a failure of the main switch tube, and the LED is burned to cause a large economic loss. . And the non-isolated driver has high requirements for insulation between the light-emitting tube and the heat sink, otherwise the lamp housing may be charged. This high-reliability insulation treatment affects the heat transfer of the light-emitting tube to the heat sink, and the junction temperature of the light-emitting tube is increased to accelerate the light decay. The cost of the isolated drive is slightly higher than that of the non-isolated drive, but the safety is good, and even if the drive fails, it generally does not cause the associated failure of burning the LED. And because the isolation driver has electrical isolation to meet the safety standard, the general insulation treatment between the light-emitting tube and the heat sink can be performed, the production process of the lamp is simple, the cost is low, and the heat resistance is small, which is beneficial to the heat dissipation of the light-emitting tube. The number of selected drivers can be used to drive all the LEDs with one driver, or multiple actuators can be used to drive the LEDs. Considering the failure of the driver, the LEDs will not be completely extinguished. The high-efficiency AD-2A40X1W isolated driver is used. This driver can drive 30-40 sets of 1 watt LED tubes in series. 90 LED tubes are driven by 2 groups of 2 drivers, and the power conversion efficiency is greater than 90. In this way, both reasonable production costs and certain fault tolerance are guaranteed, and practice has proved to be a reasonable technical solution. The mounting position of the drive is also exquisite, and it can be installed inside the lamp body or outside the lamp body. The advantage of being installed inside the lamp body is that the lamp can be installed as a complete product and can be directly installed on site. The disadvantage is that if the lamp fails in use, it is necessary to remove the lamp from the lamp post for handling, which is troublesome. If the driver is installed outside the lamp body, it can be installed in the working window under the lamp post. The isolated driver can be installed in this way. The reason is that the isolated driver is faulty and generally does not burn the LED. Only the driver is faulty. There is no need to go on the pole, and the fault is easy to handle. However, commercial street lamp drivers must be installed in the lamp body to form an integrated structure. Promote semiconductor street lights to consider the comprehensive advantages. From the perspective of power saving, the LED street lamp consumes one-third of the electricity of the sodium lamp, but its price is much higher than that of the sodium lamp. The cost recovery cycle of replacing the sodium lamp with the LED lamp is very long. However, it is not only possible to calculate the economic account from the power consumption of the single lamp, but also to reduce the line capacity of the LED lamp and the capacity of the power supply device to a corresponding one-third of the sodium lamp, and the service life is long, and the time for changing the lamp is extended. The maintenance workload is small. Therefore, the comprehensive use cost is far lower than the most commonly used sodium lamp for road lighting, and it is worth promoting.