I recently did a test of quality Gauss Qplus floodlights (zen.yandex.ru/media/ammo1/projektory-kotorye-menia-udivili-test-i-obzor-gauss-qplus), but many choose cheaper models. I tested eight inexpensive floodlights of two brands - Start and Gauss Elementary, sold in Leroy Merlin stores.
Four Start floodlights (10, 20, 30 and 50 W) and four Gauss floodlights of the cheap Elementary series (also 10, 20, 30 and 50 W) took part in the test.
All spotlights are guaranteed for 2 years.
Gauss floodlights are significantly smaller in size and lighter (this is a disadvantage, since LED cooling can be worse, which can lead to a decrease in the service life).
All spotlights have an aluminum body. The front panel of Gauss is made of partially painted glass from the inside. Start at the front has a plastic frame with glass inside.
The ten-watt Gauss is quite "toy", the size of two matchboxes.
The 50-watt models do not differ much in size, but the difference in weight is significant.
The 30-watt models are similar in size.
The 20-watt is again very different.
Searchlights Start (with the exception of the 10-watt model) are more expensive, the price of 10-watt ones is almost the same, the Start is even 10 rubles cheaper.
I tested the spotlights (after a half hour warm-up of course) and got the following results.
Spectra and results Start 50 W (left) and Gauss 50 W (right).
Unlike most bulbs, all spotlights have fair power consumption (for all tested models, it differs from the nominal by no more than 10%), with a power factor (it really is higher than 0.9 for all models, as stated), with a luminous flux (for all models it turned out to be even higher than that stated on 9-28%).
The floodlights of the two brands have different efficiency, for Gauss it is 79-93 lm / W, and for Start it is 91-116 lm / W, therefore, with the same power, the Start shines brighter.
On the packaging of the spotlights, the power equivalent of a traditional spotlight is indicated, and this is where the inconsistencies begin. The start indicates a luminous flux of 2400 lm and an equivalent of 200 W for a 30-watt floodlight (this is close to reality), and Gauss writes 2100 lm and 300 W. Of course, 2100 lumens is in no way a 300 W equivalent. And so for all models.
The color rendering index of all projectors is declared "more than 70", this is what it is (72-76). This is not enough for lighting residential premises, but it is acceptable for street lighting.
All Gauss Elementary floodlights have a very high level of light ripple (ripple rate 90-100%). Such pulsation is clearly visible and can lead to eye fatigue, headaches and exacerbation of nervous diseases.
Start also has pulsation, but less intense. The lowest light ripple is at the Start 20 W (the measured ripple factor is 23%). Such ripple is not visually discernible.
The measured ripple coefficient of the Start 30 and 50 W floodlights is 35-36%. Such ripple is barely visible visually, but will be clearly visible through the smartphone camera.
The measured ripple coefficient of the Start 10 W floodlights was 53%. This ripple is clearly visible.
Another significant difference between Start and Gauss Elementary is the type of driver (internal electronics). Gauss has linear drivers. This leads to the fact that the brightness of the floodlight changes from the slightest changes in the voltage in the network and drops sharply at a reduced voltage. When the mains voltage drops from 230 to 216-222V, the brightness drops by 5% of the nominal. At a voltage of 200V, the brightness drops by 20%, at 180V, the brightness drops by half.
The Start floodlights are based on IC drivers, so that they shine without changing the brightness when the voltage in the network changes significantly. The brightness of these floodlights begins to drop only when the supply voltage falls below 120 volts.
The Start floodlights work correctly with switches that have an indicator (do not light up or flash when such a switch is turned off).
Gauss floodlights do not work correctly with such switches (they glow dimly when the switch off, with all the LEDs on for the 10 W model, half for the 20-50 W models LEDs).
I measured the maximum body temperature of the floodlights after a 30 minute warm-up period. As expected, the smaller and lighter Gauss had temperatures 6-8 degrees higher.
Luminous flux, color temperature and color rendering index were measured using a 2 meter integrating sphere and Instrument spectrometer Systems CAS 140 CT, power consumption and power factor (Power Factor) by Robiton PM2, ripple factor by Uprtek MK350D. The minimum voltage level at which the luminous flux of the lamp decreased by no more than 5% of the nominal was measured with using the Lamptest-1 device and LATRa Suntek TDGC2-0.5. The maximum case temperature was measured with a Seek Thermal thermal imager.
Whether it is worth saving when buying spotlights is up to you. I only recommend that you refrain from buying high-ripple floodlights and linear driver floodlights.
© 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.