The darker the LED light is, the more it is due to the light decay of the LED light.
The light decay of LED light products is the weakening of the signal in the transmission of light. At this stage, the LED products produced by global LED manufacturers have different degrees of light decay.
High-power LEDs also have light decay, which has a direct relationship with temperature. It is determined by the chip, phosphor powder and packaging technology. At present, the light decay of white LEDs on the market is one of the primary problems in the march to civilian lighting.
Light decay generally 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 also rises, and finally reaches the “saturated” potential, which is the highest potential. The surface potential will decrease with time. The potential during normal operation is lower than this potential.
The process of naturally decreasing this potential over time is called the “dark decay” process. When the photosensitive drum is scanned and exposed, the potential of the dark region (the surface of the photoconductor not irradiated with light) is still in the dark decay process; the bright region (refers to the surface of the photoconductor of the light-irradiated portion) has a rapidly increasing carrier density in the photoconductive layer. The conductivity rises rapidly, the photoconductive voltage is formed, the charge rapidly disappears, and the surface potential of the photoconductor also drops rapidly. Call it “light decay.”
The darker the LED light is, the more common it is. In addition to light decay, summing up the other reasons that can make LED lights darker, is nothing more than the following three points.
LED lamp beads are required to work at DC low voltage (below 20V), but our usual mains supply is AC high voltage (AC 220V). To turn the mains into the electricity needed for the lamp, you need a device called “LED constant current drive power.”
In theory, as long as the parameters of the driver match the lamp bead, the power supply can be continuously used and used normally. The internals of the drive are complicated, and any device (such as capacitors, rectifiers, etc.) may cause a change in the output voltage, which may cause the lamp to become dark.
Drive damage is one of the most common faults in LED luminaires and can usually be resolved after replacing the drive.
2.LED burned down
The LED itself is composed of one lamp bead. If one or a part of it is not lit, it will inevitably make the whole fixture dark. The lamp beads are generally connected in series and then in parallel – so if a certain lamp bead burns, it may cause a batch of lamp beads to be off.
After burning, the surface of the lamp bead has obvious black spots. Find it, use a wire to connect it to the back of the lamp, short-circuit it, or replace it with a new lamp bead.
It’s a coincidence that the LED burns one at a time. If it burns frequently, consider the drive problem – another manifestation of drive failure is burning the lamp bead.
3.LED light decay
The so-called light decay is that the brightness of the illuminant is getting lower and lower – this situation is more obvious on incandescent and fluorescent lamps.
LED lights can not avoid light decay, but its light decay rate is relatively slow, it is difficult to see changes with the naked eye. However, it does not rule out inferior LEDs, or inferior light beads, or due to objective factors such as poor heat dissipation, resulting in faster LED light decay.