Further, the entire text was written by a neural network, the edits were minimal.
Hi all! I am holding a Sweko LED lamp in my hands. Instead of a thousand reviews, it’s always better to get one unbiased review.
It looks attractive, similar to many other lamps. I will measure all the real characteristics of light and demonstrate what possibilities the lamp has. I’ll tell you what I like about this lamp and what I don’t like. Is it worth buying?
The lamp power is advertised as 13 watts, but I will measure its actual power and show if this is true or not. I connect the lamp to 220 volts, which is the standard voltage for household outlets. When first turned on, the lamp consumes 7.9 watts of power and has a power factor of 0.59. This coefficient helps to determine how much the active power that is useful to us correlates with the reactive power that is unnecessary for us.
While it would be ideal for a power factor of unity, this is a fairly typical value for this lamp. Unfortunately, the power of the lamp does not correspond to that stated on the package, even with 230 volts.
I return the voltage to 220 volts and leave the lamp to work for 15 minutes. During this time, the lamp power increased to 8.7 watts, which is far from the declared 13 watts. Alas, the manufacturer deceived us.
To use the lamp correctly, you need to know its real quality characteristics, which are not always indicated on the packaging and do not always correspond to reality. To measure the characteristics of light, a photometer is used, which shows color temperature, color rendering index and color chart. On the chromaticity diagram, the point corresponding to the lamp is located near the radiation curve of a completely black body heated to a certain temperature, and its shift up or down shows the level of presence of the color shade of the light. Estimating the amount of shift by eye is very difficult, so the value of the delta-UVI parameter is used, which is calculated from the X and Y chromaticity coordinates and allows you to estimate the shift and shades for a reason.
As a result, it was found that the light quality of this lamp is poor, as it has a large positive shift in the yellow-green color tint and large light pulsations, which can be dangerous to eye health. It has been shown in the risk assessment chart that the use of this lamp can pose a serious health risk, and it is best not to use it in places where a lot of time is spent.
Illumination measurements were also made and it was shown that the light produced by this lamp is unstable and depends on changes in mains voltage. In general, this lamp is not recommended for home and work environments where stable, high quality lighting is required.
The packaging of the lamp does not indicate that it can be operated with a light switch. I apply voltage to the circuit and the red indicator on the switch lights up. The lamp glows brightly and there is no problem when the switch is turned off.
The package says 60mm by 110mm, but the actual size of the lamp is 117mm by 60mm.
It is also important to know how hot the lamp gets during operation. A good manufacturer should include all of these details on the packaging so that the consumer can make an informed choice. I also took the temperature. The maximum heating of the body is 83 degrees Celsius, and the flask is 40.
We disassemble the LED lamp, which has a real power of 8.7 W and indecently large light pulsations that make this lamp dangerous to health and eyes. We will analyze the design and a set of measurements for connoisseurs of technical details.
Before disassembling the lamp, I take a diagram of the illumination of the lamp in a dark room, measuring the illumination at 10 points and calculating the luminous flux of the lamp, which amounted to 625 Lumens. At the same time, the manufacturer indicates a luminous flux of 1200 Lumens, which is significantly different from the measured one.
The body of the lamp is made of plastic, and the diffuser is made of matte polycarbonate, which is matte enough so that the LEDs are not visible when turned off. The shape of the diffuser is correct, more than a hemisphere, and part of the light is directed towards the base, and part is directed forward. It’s time to look inside the lamp to look at the diode board and the power supply.
The diode board contains 15 LED packages. Each LED body measures 2.8mm by 3.5mm and contains a phosphor inside. I only see one small crystal in each package, which needs further clarification.
All LED housings are connected in series, and if one of them does not work, the entire lamp stops glowing. The diode board also has a diode bridge and a current stabilization microcircuit in the LED power circuit. The lamp is powered by 220 volts, which are connected to the connector on the diode board. Apparently there is an electrolyte in this connector, which we will be able to examine when we finally disassemble the lamp.
To measure the temperature on a diode board, find the hottest spot on the board and connect a thermocouple to it. We turn on the lamp and let it warm up for half an hour to see how the temperature changes. After half an hour of operation, the temperature on the diode board reaches 82 degrees Celsius, which is the permissible temperature for LED operation.
The voltage drop on a normally lit LED is 18.4 Volts, we divide this figure by 3. In total, 6 small LED crystals in the only spot that we were able to see under the phosphor 6 crystals in each LED housing.
The current in the LED power circuit is 27.9-28 mA.
The board has an aluminum substrate on the reverse side, on which the diodes are located. In the 220 volt power circuit there is an electrolyte of 4.7 microfarads. To cool the board, a case heatsink is used, which is in contact with a thin edge of the aluminum substrate. This is a typical cooling scheme that is used in modern LED lamps.
That’s all, Domorost was with you. Goodbye, see you next time!