Due to the rise in the cost of electronic components and the increase in the cost of shipping, more and more inexpensive LED lamps in our market are equipped with cheap linear drivers.
When the mains voltage is low, light bulbs with linear drivers not only shine dimmer, they have a ripple of light that is harmful to health.
I did a little experiment, taking four tubes with linear drivers (Osram, Voltega, Era, Ergolux) and one with a full-fledged pulse "IC-driver" (GP).
With the help of the stabilizer Shtil InStab 500 and LATR Suntek TDGC2-0.5, voltages of 230, 220, 210, 207, 200, 190 and 180 volts were supplied to the lamps. The Lamptest-1 device measured the decrease in the luminous flux, the Uprtek MK350D spectrometer measured the light pulsation coefficient. The non-circular value of 207 volts was taken for a reason - according to GOST 29322-92, the network should have a voltage of 230 volts ± 10%, that is from 207 to 253 volts, therefore 207 volts is the minimum voltage according to GOST, at which all electrical appliances must work.
In the first table, the results of measuring the percentage of lamp brightness at different voltages. The value of the luminous flux (brightness) at a voltage of 230 V, which is nominal for all lamps, is taken as 100%.
The brightness of the GP lamp with IC driver does not change when the supply voltage changes over the entire range of 180-230V. The brightness of the remaining lamps is significantly reduced, while at a voltage of 220 V, the brightness drop is insignificant 3-4%, at an allowable voltage of 207 V according to GOST, the brightness is 77-89% of the nominal (drop brightness 11-23%).
At a voltage of 180 V (in rural areas, such a voltage in the network is not uncommon), the brightness drops by 57-99%.
And here's what happens to the ripple.
At a voltage of 230 V, all lamps have practically no light pulsation (the pulsation coefficient is less than 0.7%).
At 220 V (in many sockets in our country, there is still 220, not 230 volts), the ripple coefficient for lamps with a linear driver is 0.2 - 7.9%. Such ripple is completely invisible visually, but can be seen through the smartphone camera. More than once I have received letters from users of the Lamptest website, who wrote that they bought lamps that have a pulsation of about zero on the site, and they see the pulsation through the camera. The reason is that their sockets are not 230, but 220 volts or lower.
At 207 V, permissible according to GOST, the ripple factor for lamps with a linear driver is 19 - 42%. Ripple of more than 30% is already visible visually.
The largest ripple in lamps with a linear driver is recorded at a voltage of 190-200 volts. In some lamps, it reaches 60%, despite the fact that these lamps had no ripple at all at 230 V.
Now, when testing lamps for Lamptest, I measure the ripple of all lamps at 230 volts. Perhaps you need to measure it at 220 V (then you will immediately see the ripple in lamps with a linear driver) or add an additional parameter - ripple at 207 V. What do you think is the best way to do it?
I talked in detail about the different types of LED lamp drivers and their differences in the article "A very important parameter of LED lamps, which few people know about" (https://ammo1.livejournal.com/1036413.html).
On Lamptest.ru, the driver type is displayed in the lamp cards (there may be values "linear", "IC1", "IC2", "IC3". Three versions of the IC driver differ in their behavior at low voltage 1 - the brightness decreases, 2 - the lamp goes out, 3 - the lamp starts blinking). In the table, you can enable the "Vmin" parameter, which displays the voltage at which the brightness decreases by 5%. If this voltage is higher than 200 V, the driver is linear.
Currently, the driver type does not affect the final grade. It may be worth lowering the rating for lamps with a linear driver.
Unfortunately, almost all filament lamps are equipped with linear drivers (primarily due to the fact that a full-fledged IC driver takes up more space).
If you have a good stable network and the sockets are never below 220 volts, there is nothing wrong with the linear driver - the brightness changes will be small, and the ripple is harmless. But if the network is unstable, and even the neighbors use welding machines, lamps with a linear driver are not suitable for you.
P.S. The term "IC driver" is rather incorrect (IC is just an integrated circuit, and all modern drivers are built on microcircuits), but in The term has stuck in the light industry and everyone who deals with light understands by "IC-driver" exactly a pulse driver that works in a wide range stress.
© 2021, Alexey Nadezhin
For ten years I have been writing every day about technology, discounts, places of interest and events. Read my blog on the site ammo1.ru, v LJ, Zen, Mirtesen, Telegram.
My projects:
Lamptest.ru. I test LED lamps and help figure out which ones are good and which are not so good.
Elerus.ru. I collect information about domestic electronic devices for personal use and share it.
You can contact me in Telegram @ ammo1 and by mail [email protected].