How to solve the LED outdoor lighting interior and exterior pressure difference design difficulties?

Introduction: how to deal with the pressure difference is still a hidden design difficulties, moisture-proof and breathable design can enhance the reliability of LED lamps, extend its service life.

Many commercial and residential lighting has been upgraded to LED light source, because of solid-state lighting (SSL) lighting can continue to transport more than 100000 hours of light, and it is also the most environmentally friendly and reliable lighting solutions, especially in outdoor lighting. However, outdoor applications are changeable and harsh environment, the potential leakage will lead to lamp failure and failure. Although the product developers can seal the lamp, the lamp will be isolated from the environment, but the pressure difference between the inside and outside of the lamp may cause many problems. Let us explore the pressure problem, consider the use of mechanical design method to eliminate this problem, so as to ensure the service life of lamps.

LED lamps are numerous benefits. In addition to the long life mentioned above, solid state lighting products are also fully meet the requirements of hazardous substances (RoHS), saving up to 85% of energy consumption than traditional lighting technology. Although LED itself can be used continuously for more than 20 years, but this is only in the life cycle of electronic components, and power matched with the driving power and the whole lamp like LED can be reliable and durable for the entire lighting system to provide value-added. The harsh conditions of all parts of lamps must be able to withstand the environment, whether it is the Caribbean tropical climate or Alaska cold. Severe environmental challenges, according to a RTIInternational study, the main reason for the failure of LED lamps is the power supply problems, such as capacitors and interconnected faults, voltage, water vapor or other chemical intrusion. NVC

Traditional drive power has a five year warranty period, but the experiment shows that the failure rate of these drive power is high. The reliability problem is usually caused by damage to the sealing rings, joints and connections that are affected by environmental conditions. To enhance the durability of the lamp shell most engineers usually use the following three methods, the protection of driving power and electronic components: the seal or gasket more durable to improve the seal; increase the thickness of the shell to reduce mobile shell around the sealing ring; and / or in the sealing ring or gasket fitted around more screws to keep the sealing more lasting effect the.

However, even with these measures, the seal leaks, causing water intrusion, and eventually forms a condensation on the lens and mirror. This often happens, because the entire lamp seal will not be able to handle the pressure fluctuations, whether positive or negative pressure (or vacuum). When the pressure fluctuation occurs, the sealing ring and other connection points to form a larger stress, thus affecting the sealing effect. With the passage of time, the expansion and contraction of the seals frequently will make the weak point of the sealing ring and sealing failure, loss of function, water, dust and pollutants into lamps, resulting in corrosion, short-circuit or potential faults of electronic components.

Temperature changes, whether external, internal or internal and external changes, is one of the most common causes of pressure difference. External temperature changes may be very severe (e.g., heavy rain in the hot summer months), or may change more smoothly with the seasons. Every day to night temperature can drop 10 to 20 DEG C, and the seasonal temperature difference between summer and winter can reach more than 40 DEG C. When the temperature rises, the air in the lamp expands, and positive pressure is generated on the sealing ring, the joint and the connecting point. When the temperature drops, the internal air contracts and forms a vacuum, again causing pressure on the seal. 30 degrees C temperature changes will cause about 10% of the air inflow or outflow lamps. For different sizes of lamps, the rapid decline in external temperature can cause the internal 0.5psi (35mbar) or higher vacuum. In the case of vacuum, water, dust and contaminants enter the shell. In the case of good, it will only accelerate the corrosion, but in severe cases, a catastrophic failure. Corrosion will damage the lamp contained in the LED, wire and cable, and other electronic components, and ultimately shorten the life of lamps.