Ten Little Secrets of LED Street Lamp Technology

The LED lighting industry's lighting project is not only influenced by the global environment, but also its special characteristics of the industry. The LED street light power supply is exactly the top priority of the current LED development. For the related designs in LED technology, there are currently many solutions and unique design techniques. Let's take a look at them one by one. Why do LED street light power supply be constant? The characteristics of LED lighting materials determine that it has a greater impact on the environment. For example, the temperature changes increase, the current of the LED will increase, the voltage increases, and the current of the LED will increase. Long -term surpassing the rated current work will greatly shorten LED lamp beads. The LED constant current is to ensure that its working current value is unchanged when environmental factors such as temperature and voltage changes. 2. LED street light power supply power supply Hengli accuracy The constant current accuracy on the market is poor, like the popularity scheme on the market, such as the popular stream plan, the error reaches±8%, the constant current error is too large. Generally required±3%. According to a 3%design scheme. The production power supply must be fine -tuned before it can be achieved±3%error. 3. The working voltage of the LED street light power supply power supply is generally 3.0-3.5V. After testing, most of them work in 3.2V, so the calculation of 3.2V is more reasonable. The total voltage of n lamp beads in series = 3.2* N4, LED street lamp power supply power supply current is the most appropriate, such as the rated working current of LED 350 mAh, some factories are used at the beginning, and the design is 350 mAh. In fact, the work under this current is very hot. After multiple comparative tests, it is ideal to be designed as 320 mAh. Try to reduce the heat of the hair, so that more electricity can become visible light energy. 5. How wide is the series and width voltage of the LED street lamp electricity board? To make the LED street light power supply work in the range of the input voltage range, AC85-265V, the LED series and connecting method of the light board is very important. Try not to use wide voltage as much as possible, can be divided into AC220V, and AC110V is sorted as possible, so as to ensure the reliability of the power supply. Since the current power supply is generally a non -isolation -voltage constant current power supply, when the voltage is 110V, the output voltage does not exceed 70V, and the number of series does not exceed 23 string. When the input voltage 220V, the output voltage can reach 156V. In other words, the number of series does not exceed 45 string. Do not have too much parallel number, otherwise the working current is too large, and the power supply is seriously heated. There is also a wide -voltage solution. APFC source power compensation is to use L6561/7527 to raise the voltage to 400V, and then reduce the voltage. This solution is only used under specific conditions. 6, isolation/non -isolation general isolation power supply, if it is made into 15W, placed in the LED street light power pipe, its transformer is very large, it is difficult to put in. It mainly depends on the space structure depends on the specific situation. Generally, the isolation can only achieve 15W, less than 15W, and the price is very expensive. Therefore, the cost -effectiveness of isolation is not high. Generally, non -isolation accounts for more mainstream, the volume can be smaller, and the minimum can be 8 mm high. In fact, non -isolation safety measures are done. The space allows can also be used as an isolation power supply. 7. How can LED street light power supply be matched with the lamp bead board? Some customers first design the lamp board, and then find the power supply. It is difficult to find a suitable power supply, either the current is too large, and the voltage is too small (such as 7x1wi> 350mA, or V25V), the result is severe heat, low efficiency, or insufficient input voltage range. In fact, choosing the best way to connect with each LED is the same, but the effect of the power supply can exert the best performance. The best way is to communicate with power manufacturers first and tailor -made. Or produce a power supply. 8. LED's skewers and PFC power factors areolation input AC220V high -voltage end electrolytic capacitance capacity is generally input power 1W = 1UF, AC110V1W = 2UF currently has three cases of power supply PFC: one is without PFC without power factor compensation compensation For dedicated circuits, the PF value is generally around 0.65; the second is the passive power factor compensation PFC circuit, that is, the compensation light of the passive power factor, and the flow circuit board is currently the best reliability, PF PF, PF The value is generally around 0.92; three types of active active 7527/6561 circuit are also used, that is, compensation for source power factor, called AC220V in the APFC circuit, AC110V can use electrolytic capacitors of the same capacity, choose 1W = 1W = 1.5uf. The PF value can reach 0.99, but the cost of this solution is slightly worse than that of the second solution. So the second solution is used more. For the passive PFC circuit: also known as the Chan -type PFC circuit, its DC operating voltage range is half of the peak of AC input voltage. If the input is 220V, its peak is 220*1.414 = 312V, and half of the peak voltage is 156V. Therefore, the number of LED street light power beads is up to 45 string below. Therefore, if you want to get a relatively large power factors, the number of lamps must not be too small, otherwise the best working state will not be achieved. The power supply power must meet the output power. The smaller the current working current of electronic components in the rated voltage working range, the longer the life span, the shorter the life span will. LED street light power beads are very sensitive to the amount of communication. The higher the amount of communication, the worse the comfort of the light. Generally, electrolytic capacitors should be used to maintain the voltage, and the voltage of the output end voltage is used as much as possible. The capacity of the electrolytic capacitance end of the bottom voltage should not be too small. Non -isolation input end high -voltage electrolytic capacitance selection is the same as isolation, and the output -end capacitor selects 1UF