Traditional Culture Encyclopedia - Photography and portraiture - What's with the flashing LED light bar?

What's with the flashing LED light bar?

LED light bars generally use constant current driving board as power supply.

The picture above shows the commonly used low-power LED constant-current driving board, which is driven by a single switch chip, and the current sampling adopts the primary feedback mode.

The LED driving board adopts constant current output, which conforms to the characteristics of LED lamps. Compared with constant voltage driving, it effectively guarantees the life of LED.

The LED light bar panel is generally composed of a plurality of low-power LED light beads, and the power of a single light bead is generally between 0.2-1w.. The whole lamp panel will be connected with lamp beads in series or in series-parallel combination.

The flashing of the lamp board may be caused by the following reasons:

1. Voltage instability

Generally, the voltage range of LED driver board is very wide, such as 85-264V V V. If the voltage is too low, the lamp may flicker, and if the voltage is too high, the driver chip may burn out.

2. Drive board problem

The quality problem of the driving board itself, or the virtual welding of components caused by poor heat dissipation after long-term work, will lead to flicker;

3. Individual lamp beads are damaged or almost damaged.

Because LED beads are connected in series, sometimes the consistency of LEDs is not good, which will cause individual beads to be damaged and cause the whole string of lights to flicker;

LED lamps are not completely heat-free during use. Too high temperature will lead to premature light decay, so we must pay attention to heat dissipation during use.

At present, LED lighting products are increasingly used in living, production, work and other environments, with the advantages of high light efficiency, long life, energy saving and environmental protection, and gradually replace traditional lighting lamps. As LED lights come into our lives, we will wonder whether LED lights will affect our lives and health, such as stroboscopic LED lights.

The flicker of LED lamp should refer to its stroboscopic. What is stroboscopic? What are the disadvantages?

Strobe refers to the constant fluctuation of light during the switching period, that is, stroboscopic, also called flicker. The flicker of led lamp can be divided into visible light flicker and invisible light flicker. The former is that the naked eye can directly perceive the fluctuation of light intensity, which is generally below 80Hz, while the latter is that the naked eye cannot distinguish the change of lamp brightness intensity, which is generally higher than 80Hz.

Danger caused by stroboscopic; 1, stroboscopic effect, easy to cause false eyes in work, and personal injury when operating industrial machine tools. 2, causing migraine and visual confusion. 3, causing eye fatigue, blurred vision, traditional headache. 4. Photosensitive epilepsy and flicker-induced epilepsy. 5. In the sports field, it will cause the moving objects to be unclear. 6. In photography, it will cause blind spots and black scroll bars.

What's with the LED flashing?

Theoretically, LED lamps are powered by DC power supply, so there will be no stroboscopic phenomenon in the process of lighting. The power supply is provided by alternating current, but the brightness of LED lamp changes with the period of alternating current, and the driver plays the role of power supply and rectification. From driving to LED, there will be voltage and current output ripple during the conversion from AC to DC, which generally exists at twice the frequency of power supply voltage. Due to the fast light-emitting time of LED lamp, which is ns level, these current output ripples lead to the instability of LED light source, which is the cause of LED lamp flicker.

The performance of LED lamp beads decreases, and the green wave capacitor is damaged in most cases. If the LED is broken, it can be directly short-circuited. If it is broken, an equivalent resistance diode can be connected in series. There is no need to directly change the capacitor to repair others.

The 400V/5.6uf capacitor in the general power board is broken, so it can be replaced.

Most LED strobes are caused by damaged capacitors. Capacitors keep storing and discharging ... forget it, just try it!