There is a capacitor in the driver of the LED light, which can be understood as a rechargeable battery with a small capacity: when the current passes through the capacitor, the capacitor will continue to charge - after fully charged, the capacitor will release all the stored energy at one time .

The LED light flashes, which belongs to the latter case: during the charging process of the capacitor, the light is off-because the internal current of the capacitor is small, the charging speed is very slow, so the light can be seen to be off with the naked eye. When the capacitor is fully charged, it releases electricity at one time and lights up the lamp. But because there is less energy stored, the light will go out very quickly—recharging and discharging repeatedly, and the naked eye sees the light flickering.

The fact that the lamp does not flicker during normal use is because the current through the capacitor is large and the charging speed is extremely fast.

So, what would cause a small current to flow inside the capacitor? The first is that the quality of the capacitor is not good - high-quality capacitors store a lot of electricity, and the tiny current in the line is not enough to store energy in the capacitor. The average starter is only about 20 yuan, and the cost of high-quality capacitors is probably more than 20 yuan.