Common causes of led lamp damage
1. The current voltage is not stable, and the increase of supply voltage will easily cause LED lamp damage. There are many reasons for the sudden increase of voltage.
2. A partial short circuit in the power supply path of the lamp, which is usually caused by a short circuit of a part of the circuit or other wires, which increases the voltage in this place.
3. It is also possible that LED is damaged due to its own quality, thus forming a short circuit, and its original voltage drop is transferred to other LED.
4. The heat dissipation effect of lamps is not good. As we all know, the luminescent tube is a heat dissipation process.This is also easy to damage LED lights.
5. There may be water inside the lamp, because the water is conductive, which will make the circuit of the lamp short circuit.
6. When assembling, the anti-static work was not done well, so that the LED interior was damaged by static electricity.Although the normal voltage and current value are applied, LED damage is also easily caused.
Common cause and treatment of LED flashing
The human eye normally perceives flashes of light up to 70 Hz, but not above that frequency.Therefore, in LED lighting applications, if the frequency of pulse signal is lower than the low-frequency component of 70 Hz, the human eye will feel the flicker.Of course, there are many factors that can cause LED lights to flicker in specific applications.For example, in offline low power LED lighting applications, a common power topology is isolated flyback topology.GreenPoint®, an 8W off-line LED driver that meets the energy star solid-state lighting standard;As a reference design example, since the sinusoidal square wave power conversion of the flyback regulator does not provide constant energy to the primary bias, the dynamic self-supply (DSS) circuit may activate and trigger light flicker.To avoid this problem, it is necessary to enable the primary bias to be partially discharged at each half-cycle and, accordingly, to properly select the quantities of capacitance and resistance that make up the bias circuit.
In addition, electromagnetic interference (EMI) filters are required even in led-driven applications that provide excellent power factor correction and support for TRIAC dimming.The transient current caused by the TRIAC step excites the natural resonance of inductors and capacitors in EMI filters.If this resonance characteristic causes the input current to drop below the TRIAC maintenance current, the TRIAC will shut down.After a short delay, the TRIAC usually conducts again, triggering the same resonance.During one and a half cycles of the input power waveform, this series of events may be repeated many times, resulting in a visible LED flicker.To address this problem, a key requirement of TRIAC dimming is that the input capacitance of the EMI filter be extremely low and be able to decouple through TRIAC and wound impedance.According to the formula, if the capacitance in the dimming module decreases, it can increase the resistance of the resonant circuit, which in principle can suppress the oscillation and restore the desired circuit work.