How to Distinguish the Quality of LED Bulbs? Part.1

Many people have the opportunity to touch an LED bulb that has been lit for several hours. "How can it be so hot, isn't the LED a cold light source? This light is too hot, it should be a very poor-quality bulb!" He might say.

Debates are often heard about which of the different weight LED bulbs are better quality. Some people think that heavier LED bulbs are better quality, and some people think that light weight is better quality in turn.

So, does the heated LED bulbs have the better quality? Is the heavier one better, or the lighter one? How can we distinguish the quality of LED bulbs from bad? These become a topic worth discussing.

What should a high-quality LED bulb look like?

First impression

We don't need to light the LED lamp first. We can see a lot of details about the quality from the packaging of the lamp.

1. Exquisite packaging design: Manufacturers or brands with deep understanding of products and quality control will choose packaging with exquisite design and strong materials, which can provide good protection for LED lamps.

In order to allow users to fully compare and understand the products, many product parameters will be listed on the package:

2. Important parameters: Brand, power, luminous flux, color temperature, lighting angle, applicable voltage and grid frequency, input current of lamp, whether dimming is supported, etc.

3. Necessary information: Rated service life, precautions for use, applicability to wet environment, product size, weight, power factor, certification and regulations that the product complies with, energy efficiency identification, power consumption under working mode, additional functions of the product, power conversion that can replace the traditional bulbs, etc.

When you open the package and see the LED bulb, the high-quality LED bulb will leave a very good impression.

4. Clean appearance: Except for the printing on the lamp, there are no abnormal impurities and dirt.

5. Compact package: All parts are well fixed, and there will be no obvious sound when shaking the bulb.

6. Printing of products: The printing is clear and beautiful, and the information is complete and accurate. At least including power, luminous flux, color temperature, lighting angle, applicable voltage and grid frequency, input current of lamp, whether dimming is supported, etc.

In general, the packaging of high-quality LED bulbs and lamps can leave the impression that they are clean and tidy, informative and accurate, with necessary warnings and application instructions.

Quality of light

Take the LED A60 / A19 as an example. Now let's turn on the LED A60 bulb.

1. The ray of light is uniform and soft: The light emitted by the high-quality A60 bulb should be uniform and soft.

2. High color rendering index: Its light should have high color rendering. This can make you see the color of a picture more realistically and vividly under the light, or it can be used to fill up the light for objects or people when taking photos, or it can be used for more professional work on color.

3. Stroboscopic: Its light will not have stroboscopic. If people work and live under the stroboscopic light for a long time, it will endanger people's health, and even cause serious damage due to the visual retention effect caused by stroboscopic light in special workplaces.

4. Spectrum: A good LED light can even simulate the effect of sunlight to make you feel like bathing in the sun. It will also consider the factors of health rhythm for you, so that you can concentrate on improving efficiency at work. Relax fully during rest and go to sleep safely.

Reliability

A good LED bulb will certainly perform well in reliability. The reliability mainly includes the management of LED temperature, the reliability of driving, and the matching of driving + LED + shell heat sink.

The management of LED chip temperature: As we all know, LED is a semiconductor light-emitting component, so it will have the unique property of semiconductor components: sensitivity to temperature. This leads to the heat dissipation problem of LED, which has been researched and solved by engineers. Good heat conduction and heat dissipation design enables the heat generated by LED during operation to be effectively transferred to the shell radiator, which will make LED work at a suitable temperature, delay the attenuation of luminous flux, and reduce the color point deviation caused by temperature.

The reliability of driver: The LED cannot be directly connected to the mains, and it needs constant voltage and DC power to work normally, which requires another core component of the bulb, LED driving (power supply). The reliability of the drive also directly affects the reliability of the LED bulb. A good LED bulb will pay more attention to the design of the drive, and generally redundant part of the load capacity of the drive, and more reliable components will be used.

Matching and rationality: High quality LED bulbs can fully match the LED and driving parameters. And through the ingenious and reasonable shell heat dissipation design, the heat generated by the lamp can be quickly and effectively transferred to the outside, so that the lamp can work stably for a long time.

Applicability

Good LED bulbs will take into account the certification standards of different countries and regions, power grid characteristics, temperature and humidity and other factors.

Different countries have different certification requirements for product reliability and energy-saving design, and the rated voltage also varies greatly. Correspondingly, LED bulbs should be treated differently in design and production, instead of adopting one product standard in all countries.

In some areas, the power grid voltage may fluctuate, so the LED bulbs used in these areas should be designed with special drive according to the power grid fluctuation to avoid the power changes that damage the reliability of LED bulbs caused by the power grid fluctuation. You will find that when the voltage input to the bulb changes greatly, the power of the bulb is almost constant!

In some areas, the air is humid and the temperature is high all the year round. Good LED bulbs are designed to cope with high temperature and humidity.

What are the manifestations of low-quality LED bulbs?

Unfortunately, some manufacturers and brands have insufficient technical capacity, or quality control problems, or even ignore product quality for the sake of profit. In short, there are still some LED bulbs with poor product quality in the market. What are their performances?

First Impression

Product packaging:

The printing quality is not good, and a lot of energy is not invested in designing and improving the packaging.

The material of the package is soft and cannot give the LED lamp good protection.

Lack of necessary product information: For example, lack of one or more kinds of electrical parameters and optical parameters.

Lack of additional warning information and quality assurance information: Such as rated service life and precautions for use.

Lack of product certification and regulations.

Lamp body:

Very light weight, lighter than similar products of other brands.

The printing on the lamp is not clear, or even no printing. The information is incomplete, and even the rated voltage frequency is not available.

There are a lot of impurities and dirt.

The product has obvious sound with shaking.

Generally speaking, low-quality LED bulb packaging and lamps often lack the necessary product information. The materials used are often light, thin and soft, and the first impression maybe the price is very cheap.

Quality of light

The color rending index reached 80 barely, and even some lamps did not reach 80.

There will be some of the flicker in different degrees.

Reliability

For LED bulbs with poor quality, the temperature management of LED and driving components is often out of control:

The matching of the drive + LED + housing heat sink is not good, which will make the heat generated by the LED and the drive cannot be effectively transferred to the housing heat sink, which will make the LED and the drive work under high temperature conditions.

Moreover, the heat dissipation capacity of the shell of this product is often insufficient. Even if the heat is transferred to the shell, the shell is unable to dissipate the heat, resulting in a short service life of the product. 

In order to reduce the cost, some manufacturers meet the requirements of the rated photoelectric parameters, and even let the LED and the driver run overloaded, such as allowing the LED with the rated current of 100mA to work at 120mA, or allowing the driver with the rated power of 10W to carry 15W LED lamps. This approach is very risky and unreliable.

Applicability

The power of low-quality LED bulbs often changes with the fluctuation of the power grid. This easily causes led and drive losses.

Bulbs often do not meet the certification, or at least some of the items that do not meet the certification, such as electromagnetic compatibility.