Why Does the LED Light Get Dimmed When It Is Used?

27 Jan.,2021

The LED light will dim when it is used because the LED light will attenuate. The light attenuation of LED light products is the weakening of the light signal during the transmission process.


The LED light will dim when it is used because the contact us will attenuate. The light attenuation of LED light products is the weakening of the light signal during the transmission process. At this stage, the degree of light attenuation of LED products produced by major global LED manufacturers is different. High-power LEDs also have luminescence attenuation directly related to temperature. It is determined by chip, phosphor and packaging technology. At present, the light attenuation of white LEDs on the market is one of the most important issues in moving towards civil lighting.

Light attenuation usually refers to its luminous flux. When the surface of the photosensitive drum is charged, as the charge accumulates on the surface of the photosensitive drum, the potential continues to rise, eventually reaching the highest potential "saturation" potential. The surface potential will decrease over time. Generally, the working potential is lower than this potential. The process in which the potential naturally decreases with time is called the "dark decay" process. When the photosensitive drum is scanned and exposed, the dark area (referring to the surface of the photoconductor not irradiated by light) is still in the dark attenuation process; the bright area (referring to the surface of the photoconductor in the light-irradiated part) carries current in the photoconductive layer The sub-density increases rapidly. The conductivity rises rapidly to form a photoconductive voltage, the charge quickly disappears, and the surface potential of the photoconductor also rapidly drops. Call it "light attenuation".

It is very common for energy-saving LED lights to dim when they are used. In addition to light attenuation, Energy-Saving LED Lamp Manufacturers also summarized several other reasons that led to the dimming of LED lights, but there are three points.

LED Lights

LED Lights

1.The drive is damaged

Environmentally Friendly LED Lights require low DC voltage (less than 20V), but our usual commercial power supply is AC high voltage (AC 220V). In order to convert the utility power into the power required by the lamp beads, a device called "LED constant current drive power supply" is needed.

In theory, as long as the driver's parameters match the lamp bead board, it can be continuously powered and used normally. The internal part of the driver is more complicated, any equipment (such as capacitors, rectifiers, etc.) failure may cause the output voltage to change and then dim the lights. Drive damage is the most common type of failure in LED lights, and can usually be resolved after replacing the drive.

2. LED burns out

The LED itself is a combination of lamp beads one after another, if one or part of them is not bright, it will inevitably make the whole lamp dim. Lamp beads are usually connected in series and then in parallel. Therefore, if one lamp bead burns out, a batch of lamp beads may not light up.

Find obvious black spots on the surface of the burned lamp bead, find and connect the wire on its back, and then short-circuit it; or replace it with a new lamp bead to solve this problem.

The LED will burn out occasionally, which may be accidental. If it burns frequently, you must consider the driver problem-another manifestation of driver failure is burning lamp beads.

3. LED light attenuation

The so-called light attenuation means that the brightness of the luminous body is getting lower and lower, which is more obvious in incandescent and fluorescent lamps.

LED lights cannot avoid light decay, but their light decay speed is relatively slow, and it is usually difficult to see changes with the naked eye. However, it is not ruled out that inferior LEDs, inferior light bead plates or objective factors (such as poor heat dissipation) lead to faster LED light decay.