I got a UV LED nail dryer with a declared power of 90 watts. I became curious how many times the Chinese are deceiving and what its real power is.
Dryer costs $ 13.50 with free shipping from Russia.
They promise 45 dual spectrum LEDs (365 + 405nm) and 90W power, but the box says "54W / 80W / 150W Max".
There are really 45 LEDs.
For connoisseurs of Ohm's law and the power formula, 12V 6A is written on the power supply. :)
Do you believe that a tiny power supply weighing 68 grams can deliver six amps? I don’t believe it either.
Let me tell you in a nutshell how the dryer works. It has four buttons (the inscriptions on them are upside down, since the dryer is supposed to be used in the salon, and the inscriptions on the buttons are for the master, not for the client whose hand is in the dryer).
The first three buttons turn on the LEDs for 10, 30 and 60 seconds, the fourth for 99 seconds with reduced power. In addition, the LEDs are activated by the IR sensor when the hand is placed in the dryer (default is 120 seconds after the execution of any of the programs started by the button, at the time of the last executed programs). Whenever the LEDs are on, the time is counting down on the indicator.
My spectrometer has a range of 380-780 nm, so it "sees" only the visible part of the dryer LED spectrum. Its peak falls on exactly 400 nm (and not 405 nm, as promised by the manufacturer).
And now the "moment of truth". We measure the power of the dryer. In order to make the measurements more accurate, I did not measure the consumption from the mains, but connected a power meter between the power supply and the dryer.
In normal modes, the dryer consumes 22 watts.
In reduced power mode - 6.1 W.
The Chinese watt turned out to be four times the real one!
However, once I came across an LED light bulb from Aliexpress, the power of which turned out to be five times less than promised (https://ammo1.livejournal.com/881087.html).
I made a video about the dryer and showed the power measurement process there.
https://youtu.be/XaxWgiB6NuU
However, judging by numerous reviews, the dryer performs its function normally, and I don't know why instead of real 22 W they write 90 W.
© 2020, Alexey Nadezhin
The main topic of my blog is technology in human life. I write reviews, share experiences, talk about all sorts of interesting things. My second project - lamptest.ru. I test LED bulbs and help figure out which ones are good and which are not so good.