Six parameters to roughly judge the quality of LEDs: 1, […]
Six parameters to roughly judge the quality of LEDs:
1, the luminous flux (Φ) unit is lumens (lm)
2, color temperature (k) unit is Kelvin
3, color rendering index (ra) color rendering index
4.Light source efficiency (lm ∕ w)
5. Power factor of power supply
6, cooling effect
You need a lamp that meets these six parameters, basically you can judge the quality of a lamp!
LED bulbs, professionally known as LED bulbs, the most common household power is 3W, 5W, 7W, 9W, 12W, 18W, 21W, 24W for engineering, even greater power, 40W, 80W, 120W , 150W, etc.
3W bulbs are generally used on table lamps and bedside lamps.
5W bulbs are generally used on floor lamps.
7W bulbs are generally garages, nanny rooms, etc.
3 lamp head selection
The lamp holder has a bayonet and a screw socket, and the commonly used lamp holders include E27, E14, E26, etc. These are screw sockets. The letter E represents an Edison-threaded screw lamp holder or lamp holder. The number on the back represents the outer thread of the lamp holder. An integer value of the diameter in mm.
Therefore, E27 represents a screw cap with an outer diameter of 27mm, and E14 represents a screw cap with an outer diameter of 14mm. The power of the LED lamp is not related to the size of the lamp cap. LED bulbs of the same power can use either the E27 lamp cap or the lamp cap. E14 lamp cap, of which E27 is the most commonly used lamp cap.
There is also a B22 lamp holder. B22 lamp holder is a kind of lamp holder. The lamp holder refers to an interface for installing a light bulb at the end of an electric light cord. It is a lamp component that fixes the lamp to a lamp holder and connects the lamp to a power source.
Electric light source mainly uses the method of naming lamp heads and lamp holders. The meaning of the related symbols is: B bayonet lamp head, the number behind B indicates the diameter of the shell, such as: B22D / 25 × 26--refers to the bayonet lamp head with two contact pieces and a diameter of about 22mm; the total length is about 25mm, The skirt diameter is approximately 26mm.
4 parameter summary
In fact, no matter what kind of LED you buy, you don't actually look at the appearance, but the heart inside. It doesn't work just by looking at it. The factory needs to use the spectrum analysis system to measure the corresponding test report. There are at least five parameters on the report. In comparison, the heat dissipation parameter depends on the aluminum shell. There is no way to look at the light decay with the naked eye, it needs to be measured by professional instruments.
5 price analysis
For example: the light bulb can be divided into: chip, aluminum substrate, housing, power supply, these parts. Each section has different brands, different batches, and different prices. Equivalent to a free combination. Every part is used well, so the price is very high, otherwise the price is very low; there are other parts that are used well, and some are poor, the price is moderate.
So how should we identify it?
1. If you want the seller to take out this test report, you can see the five parameters at a glance.
2, Chongxi Lighting recommends not to buy products below 6 yuan on Taobao, after all, LED lights have not yet reached the stage of popularization, and national standards have not yet come out.
3. When looking at the shell, it determines the service life (heat dissipation) of the LED lamp beads; the appearance is the same, and the thickness of the aluminum material determines the price.
Choice of 6 color temperatures
The color of light: yellow light: color temperature: 2700-3500K. (To achieve a warm effect, warm colors)
White light: color temperature: 6000-6500K. (To achieve a clean and tidy effect, cold colors, more used now in summer)