??Why Do LED Lights Get Dimmer Over Time and Flicker???

??Why Do LED Lights Get Dimmer Over Time and Flicker???

The reason LED lights get dimmer as they are used is due to light decay. The light decay of LED light products refers to the weakening of the signal during light transmission. LED manufacturers around the world produce products with varying degrees of light decay. High-power LEDs also experience light decay, which is closely related to temperature and determined by factors like chips, phosphors, and packaging technology. Currently, the light decay of white LEDs in the market is a major concern for civilian lighting. ??

Light decay generally pertains to its luminous flux. When charging the surface of a photosensitive drum, as charge accumulates, the potential rises until it reaches the "saturated" potential. Over time, the surface potential drops. This natural decline is called the "dark decay" process. When the photosensitive drum is scanned and exposed, the dark area's potential remains in the dark decay process, while in the bright area, the carrier density in the photoconductor layer increases rapidly, conductivity rises, forming a photoconductive voltage. The charge disappears quickly, and the photoconductor's surface potential drops rapidly, known as "light decay". ??

LED lights getting dimmer is a common occurrence. Aside from light decay, there are three main reasons. ??

??Driver Damage

LED lamp beads require DC low voltage (below 20V), but our mains power is AC high voltage (220V). We need an "LED constant current drive power supply" to convert mains power. In theory, if the driver's parameters match the lamp bead board, it can supply power continuously and work normally. However, a complex driver can experience malfunctions in devices like capacitors or rectifiers, leading to output voltage changes and dimming of the lamp. Driver damage is a common fault in LED lights and can usually be resolved by replacement. ??

??LED Burnout

LEDs are composed of lamp beads. If one or some don't light up, the whole lamp will dim. Lamp beads are usually connected in series and then in parallel. A burned lamp bead can cause a batch of them to fail. There are obvious black spots on the burned bead. Short-circuit it with a wire or replace it to solve the problem. Occasional burnout might be a coincidence, but frequent burnout could indicate a driver issue. ??

??LED Light Decay

Light decay means the brightness of the light source decreases. This is more evident in incandescent and fluorescent lamps. LEDs also experience light decay, albeit at a slower rate. Inferior LEDs, light bead boards, or poor heat dissipation can accelerate the decay. ??

Why do LED lights flicker? What causes LED light flickering? The driver of an LED light contains a capacitor. Think of it as a small-capacity rechargeable battery. When current passes through, it charges. Once fully charged, it releases all stored energy at once. LED flickering occurs when the capacitor is charging (light off due to slow charging from small current) and then releases energy to light up the lamp briefly. Normal use without flickering is due to large current and fast charging. ??

So, what causes a small current in the capacitor? Poor capacitor quality is one reason. A high-quality capacitor stores more electricity and tiny circuit currents can't charge it. A typical starter is around 20 yuan, while a quality capacitor likely costs more. ??

We can also look at the sources of tiny currents.

Possibility 1. Switch Controls Neutral Line

If the switch controls the neutral line, the live line is directly connected to the lamp (capacitor). The live line has high potential. A potential difference forms if there's a low potential in the line, creating voltage. This causes a weak current in the capacitor and leads to LED flickering. This is a construction issue that can only be resolved by changing the neutral and live line directions. ??

Possibility 2. Neutral Line is Charged

Even if both ends of the lamp are connected to the neutral line, it's not always problem-free. Lamp switches are often unreliable. Issues like close neutral and live wire terminals or poor insulation can cause the neutral line to be charged. Test your switch with a pen – often, the neutral wire terminal also lights up. For most switches, even if the neutral is charged, the voltage is low and doesn't cause current. But poorer insulation can lead to capacitor charging. Switches with indicators also generate weak currents when off, which can charge the capacitor. Replacing with a better quality switch without an indicator solves this. ??

Possibility 3. Induced Electricity

If there are many wires around the capacitor, other wires working can create induced electricity. Two parallel conductors form a new capacitor. Solutions include replacing the light with a fluorescent or incandescent lamp or connecting a 220V relay coil in series to the LED starter to consume the induced electricity