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In the process of using LED lights, there may be many common problems, such as flickering, buzzing, bulbs not bright enough, glare, and even smoke. If these problems are not addressed promptly, they may result in damage to your circuits or bulbs, or other financial losses such as explosions and fires, resulting in fire or injury. I've seen reports of solar street lamp batteries exploding. The purpose of this paper is to analyze and solve the problems we often encounter, so as to improve the quality of LED lamps.
One of the most common problems with LEDs is light flickering. The lighting is basically flicker. When you hold your phone's camera and point it at the lit light, you'll notice that most of the LED lights in the video are flickering. This flicker can be severe if poor-quality LED bulbs or floodlights are used. If the scintillation frequency is below 80Hz, it can be seen with the naked eye. This can be a serious problem, as flickering lights can cause fatigue, headaches, vomiting, and even seizures. It's hard for our eyes to get used to these flashes: therefore, we need to understand the cause and fix the LED flicker.
If the wire connection between the LED light and the circuit is loose, you may experience light flickering. This is because the current is periodically blocked due to electromagnetic interference. The fix is to check all the connections in the circuit to see if any wires are about to break or disconnect.
If you buy a very cheap LED, the flicker will be very noticeable. Due to the poor welding process between the gold wire and the LED chip in the LED packaging process, the internal components are easy to loosen. In addition, poor-quality LED lights have poorly designed PCBs that do not receive current properly, so we see rapid fluctuations in brightness. One of the effective ways to solve this problem is to buy good quality brand LED lamp beads. We can look at the brands of LED chips they use. For example, Philips Lumileds or Osram Square would be a better choice. They used eutectic welding techniques to eliminate the flickering of LED lights.
If the connection line between the PCB board and the LED power supply is not in good contact, the LED light will blink. Bad contact between the LED power output and the PCB board will affect current transmission. Before checking the LED light, we should turn off the power to prevent electric shock. Your room is dark after the lights are turned off. We can put a portable work lamp under the lamp to provide enough brightness.
Knowing your type of dimmer is crucial to diagnosing problematic strobe LED lights.
The pulse width modulation (PWM) dimmer pulse represents the current and voltage sent to the bulb, while the width is the duration. PWM dimmers alternate pulse durations to reduce overall brightness. In other words, it dims LED lights by quickly turning them on and off. Poor quality dimmer switches will produce pulses of inappropriate width (< 100Hz) electrical signal, causing the LED to appear noticeable flicker. The flicker effect is especially significant if the light is dimmed further, as the duration between each pulse is longer.
Constant current reduction (CCR) dimmer
As the name suggests, it changes the current of the circuit to produce different levels of brightness. It is usually used for 0 to 10V DC power supplies. The LED driver sends a corresponding dimming signal to the lamp. In this case, a continuous current is provided and no discrete pulses are formed in the circuit.
If you have high power for your backyard or playground (<100W) LED floodlight. A bad LED driver can cause blinking problems. Before buying LED, we can look at the brand of LED driver. Inventronics LED driver is one of the best and most reliable power supplies we have used at present, with a failure rate of less than 0.3%.
In order to make the price cheap, Many LED driver suppliers only install an IC to achieve a high power factor in the front pole of the power board, but the disadvantage is that it will lead to light flicker if you use the phone camera to the lamp can see, this is called monopolar PFC. And in high-quality LED drivers, will use bipolar PFC design, the front pole and the rear pole of the power board each use an IC to achieve a high power factor, the advantage is absolutely no strobe, power and efficiency are high, and the biggest disadvantage is that the unit price is high. Therefore, the price and cost of LED drivers with good quality and poor quality will vary greatly. If there are requirements for strobe lighting, try to choose a high-quality bipolar PFC driver, such as the Inventronics EUM series.
For people who have a lot of high-power appliances in their homes, such as air conditioners, heaters, vacuum cleaners, etc. If a large amount of voltage is extracted from the same circuit, the bulb may flicker. To solve this problem, we can turn off some devices and see if the flicker problem improves.
Flicker problems are also common in LED commercial and sports lighting. Their lighting standards are even higher than for residential applications. LED lights should not be flicked under high-speed cameras, except that they do not flicker visible to the human eye. Let's say we're filming. In 960 fps video, flickering can greatly affect image quality. MKLIGHTS LED sports lights use constant current step-down dimming. They support high-speed photography up to 6000 Hz. Applicable to football stadiums or other stadiums hosting international competitions.
Buzzing is another common problem with LED lighting. If your canopy lights or other LED floodlights emit this annoying humming sound, it could be a sign that your circuits are overloaded. For example, if the dimmer only supports 300W LED lights, but you are connected to more than 200W, there will be a buzzing sound. Where is the sound coming from? Mainly due to the vibration of the electronic components in the lamp. They vibrate at a specific frequency, say 100 to 120 Hertz. The buzz of the LED light indicates an anomaly, and once we hear it, we should check the light. And circuits to ensure safety. Also, we can disconnect some lights to see if we can improve this problem.
After the installation and use of LED street lamps for a period of time, people often ask why the LED lights will dim. The problem occurs with both indoor and outdoor LED lights. Let's discuss the reasons as follows.
If the LED does not work at the rated voltage and current, the LED lamp cannot reach its maximum brightness. If you want to use your own driver, you need to know LED voltage, current, LED series, parallel, etc. If the rated output of the driver does not match the rated input of the LED board, the floodlight bulb will not light up or even burn out. Therefore, it is highly recommended to purchase complete lamps.
If the wires are not well connected, some LEDs will not light up, reducing the overall lumen output.
Video from Youtube about new street lights flickering and flashing
If used for a long time, the brightness of the LED lamp will decrease. This is caused by the decay of the LED lamp, so it no longer produces 100% light flux. If the LED lamp is rated at L70 for 100,000 hours, after 100,000 hours the lumen output will drop to 70% of the original value, which is the normal light decay of the LED lamp. Today, most LEDs have a lifespan of 50,000 to 100,000 hours, or 20 to 30 years, depending on how long you use them each day.
Residents may also complain that their LED lights do not work if the ambient temperature is high. According to scientific research, LED produces maximum brightness when the junction temperature is about 25℃. If the working environment is very hot, such as 40-60°C, the lumen output of the LED lamp will drop to around 65% to 80% of its maximum value. Quite the opposite. Cold conditions favor LEDs because they can be brighter than their original values. For industrial applications such as foundries and nuclear power plants, the ambient temperature can reach more than 80℃, so special treatment is needed for LED lights.
Some people may complain that LED lights cannot be dimmed when connected to a dimmer switch. For example, the customer purchased a street lamp with DALI2 dimming. After connecting the DALI2 dimmer, the customer found that the lamp could not be dimmed. Actual customers' dimmers may still be old DALI dimmers, so there are signal-matching problems. When you encounter this problem, you first need to check that the bulb can be dimmed. Before you buy LED lights, you can clearly see that these lights are labeled "Dimmable" (if they are available). If the dimmer switch is connected to a non-dimmable LED bulb, it will usually remain at 100% brightness no matter how you adjust the brightness of the switch. This is because the lamp's LED drive power supply cannot change the output current because it is not dimmable.
Glare is the intense glare of light from a source, commonly known as a blinding light, that blurs our vision and affects our quality of life. Like the words in a magazine, because reflection is hard to read. In addition, the glare from the white reflection of light can create white spots on the TV screen.
4.1 Reducing brightness is one of the common ways to fix glare. For example, the parking lot outside the supermarket only needs 75lux. One parking space covers an area of 15 square meters, so one parking space needs 1125LM. At present, the lighting efficiency of most LED street lamps is 130LM/W, while the LED road lighting efficiency produced by MKLIGHTS is above 160LM/W, so the actual power of LED lights is 1125/130=10W. Considering the various losses, it is possible to get a standard of 50W, and parking lots usually choose to install LED parking lights above 100W. Therefore, in this case, if the glare is too great, consider choosing LED parking lights with lower power.
4.2 Another way to reduce glare is to add a shield to the LED lamp to make the beam more directional. For example, to prevent the light from the back of the LED street lamps from reaching the residential buildings and affecting the sleep of the residents, we can add a shield to the back of the street lamps so that there is no light on the back of the light pole.
While blue light can improve our reaction time and mood, it does affect our health at night. The blue light from LED lights suppresses the production of melatonin in the body, which can affect our sleep cycles and quality, and prolonged exposure to blue light may also damage the retina. Blue light leaks can also pollute the sky, causing it to glow at night. To reduce the amount of blue light, choose LED lights with a lower color temperature, such as 3500K to 5000K. LEDs with a color temperature above 6000K produce more blue light. Depending on your needs and preferences, you can choose warm white LED (about 3000 to 3500K) to create a relaxed atmosphere.
Another common problem is the low uniformity of LED lights. What is uniformity? It basically shows how evenly light is distributed over an area.
As can be seen from the above comparison, the lighting uniformity of the left court is lower. There are eight visible points of light on the ground. With such low uniformity, our eyes would not be able to see the entire ground. Uneven dimming and bright lights can also strain our eyes because our eyes need to constantly adjust to the change. One of the common ways to solve this problem of low uniformity is to use LED lights with large beam angles or to increase the number of lights to further improve uniformity. We can even use secondary reflections to illuminate the area. For example, we can point floodlights at the ceiling. This uses reflected light to illuminate an indoor area, such as a house or playground. As a result, you get highly even lighting because the ceiling acts as a diffuser for soft lighting. However, the downside is that we will need more LED lights because some lumens are absorbed by the ceiling, plus the beam scattering in different directions is wasted.
Outdoor LED lights often encounter waterproof problems, which is also a headache for many users, such as the so-called IP65 or IP66 LED floodlights, not long before the batch water problems, most of the water problems in the front glass surface, the waterproof strip is poor or not enough sealing, but a LED lamp water will lead to damage to the internal components, General lamps are scrapped directly. So how to choose a good waterproof LED lamp? First of all, it is very important that when purchasing LED lamps, customers must ask the supplier to provide the waterproof test report of the third-party large laboratory, such as TUV, SGS, etc. Secondly, when choosing suppliers, we need to choose suppliers with strength and many years of production and manufacturing experience. Finally, the samples should be sampled to test the waterproofing and other issues before the order is delivered or placed.
Outdoor lamps will be exposed to the sun, and the use of the environment is very harsh, especially in some areas near the sea, the salt in the air is particularly high, and the salt is the most likely to lead to the corrosion of the metal shell, so a very important link in the production of outdoor lamps and lanterns is to do a good job of anti-corrosion treatment, there are many ways, such as spray layer thickening, hot galvanizing, electroplating and so on are anti-corrosion treatment means, But it takes at least 1,000 hours of salt spray testing to determine whether it works. So when customers buy outdoor lamps, such as LED street lamps, how to judge? First, when buying LED street lights, customers need to ask suppliers to provide at least 1000 hours of third-party laboratory salt spray test reports; S Secondly, the lamps must be purchased with exposed screws and must be stainless steel, at least 304 stainless steel, preferably 316 stainless steel screws; Finally, it is to try to select professional suppliers, who have their own testing laboratories and can clearly know how to do anti-corrosion treatment. Although this work is very troublesome, but it will save a lot of money for the future, because once the purchased lamps are not up to standard, it may be faced with the situation of replacement in 2-3 years.
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