What is the dimming principle of LED lamp?

1. Pulse width modulation (PWM) digitizes the square wave of the power supply and controls the duty cycle of the square wave, thus achieving the purpose of controlling the current.

2. Constant current power supply control can easily adjust the current with analog linear technology.

3. Grouping control: a simple grouping device is used to group control multiple LEDs.

Extended data

For general lighting, people need a white light source more. 1998 white LED has been successfully developed. This kind of LED is encapsulated by GaN chip and yttrium aluminum garnet (YAG). The GaN chip emits blue light (λ p =465nm,

Wd=30nm), the high-temperature sintered YAG phosphor containing Ce3+ emits yellow light with a peak of 550nm after being excited by this blue light.

Blue LED

Install the substrate in a bowl-shaped reflective cavity and cover it with a thin layer of YAG-mixed resin, about 200-500nm. Light Emitting Diode(LED)

Part of the blue light emitted by the substrate is absorbed by the phosphor, and the other part of the blue light is mixed with the yellow light emitted by the phosphor to obtain white light.

For InGaN/YAG white LED, by changing YAG

By adjusting the chemical composition of phosphor and the thickness of phosphor layer, white light with color temperature of 3500- 10000K can be obtained.

Blue LED technology is simply a more energy-saving and efficient way to emit light, and can also be applied to technology products such as cameras and mobile phones.

Lighting equipment made of blue LED technology is more energy efficient, which greatly reduces the energy consumption of the earth. According to the available data, 25% of the world's electricity is used for lighting. After using LED lamps, the electricity used for lighting is reduced to 4%, which undoubtedly changed the whole world.

From the discovery of LED effect in 1907 to the formal invention of LED in Shuji Nakamura in 1993, and then to the commercialization of LED lamps in 1999, LED has experienced nearly a hundred years of development. Before that, people have been using incandescent light bulbs invented by Edison in the last century. Incandescent light bulbs waste most of their energy on heating, and about 90% of their electricity is wasted.

The appearance of LED lights greatly reduces the power required for lighting. The power required by LED lamps with the same wattage is only110 of incandescent bulbs. At the same time, LED has the advantages of long life, environmental protection and maintenance-free, and quickly replaces incandescent bulbs.

In 20 12, the government of China announced a total ban on the sale and import of incandescent lamps for general lighting with power exceeding 100 watt. Incandescent lamps, which have accompanied the older generation of China people for decades, are coming to the end of history.

As written in the Nobel Prize in Physics: "Incandescent lamps will illuminate the 20th century, while LED lamps will illuminate 2 1 century."

Advantages:

1, high efficiency and energy saving

Only a few kwh of electricity is consumed in one thousand hours (ordinary 60W incandescent lamp consumes 17 hours 1 kwh, and ordinary 10W energy-saving lamp consumes 100 hours 1 kwh).

2. Long service life

The semiconductor chip emits light, has no filament, no glass bubble, is not afraid of vibration and is not easy to break, and its life can reach 50,000 hours (the life of ordinary incandescent lamps is only/kloc-0.000 hours, and that of ordinary energy-saving lamps is only 8,000 hours).

Step 3 be healthy

Light health lamp does not contain ultraviolet rays and infrared rays, and does not produce radiation (ordinary lamp contains ultraviolet rays and infrared rays).

4. Environmental protection

It does not contain harmful elements such as mercury and xenon, which is beneficial to recycling and will not produce electromagnetic interference (ordinary lamps contain elements such as mercury and lead, and electronic ballasts in energy-saving lamps will produce electromagnetic interference).

5. Protect your eyesight

DC drive, no stroboscopic (ordinary lamps and lanterns are driven by alternating current, which will inevitably produce stroboscopic)

6. High luminous efficiency

10% of low-heat electric energy is converted into visible light (95% of electric energy of ordinary incandescent lamps is converted into heat energy, and only 5% of electric energy is converted into light energy).

7. High safety factor

The required voltage and current are small, the heating is small, and no potential safety hazard is generated. It is used in dangerous places, such as mines.

8. Huge market potential

Low voltage, DC power supply, storage battery, solar power supply, remote mountainous areas and outdoor lighting and other places lacking electricity.

References:

Baidu encyclopedia -LED dimmer