In this page we report our impressions about a recent LCD monitor with LED backlight.
We don't want to do advertising for any industry so we don't report the brand and model of this monitor. After all, all manufacturers of LCD monitors use the components made from the same manufacturers of LCD panels, and so there is very little difference among their products, besides the esterior look and shape of the monitor.
Previously we had already tried some LCD monitors with LED backlight but they resulted still emitting a lot of mid and high frequency EMF, probably because of their internal switching power supply and their main electronic board.
We have decided to try this LCD monitor because it not only has LED backlight, but it also has an external power supply and the main electronic board placed in the base instead of being attached on the back side of the LCD module, there are just a few products with this shape in commerce.
Having the external power supply instead of an internal one is surely better because the EM radiation coming directly from the circuits of the power supply can be partially avoided. Anyway, some of the electromagnetic noise passes from the external power supply to the monitor's main board along the power supply cable.
Having the main board detached from the LCD panel is another reason that reduces the EM radiation of the whole monitor.
We can't provide objective measures of the EM field since these EM fields are already very low and we need several expensive instruments to measure them, so we can just express our impressions and sensations.
As soon as we turned on the monitor, we started notice some high frequency EM field from the monitor, but it was a lot lower than the EM field of LCD monitors of two years ago, which had fluorescent backlight and internal power supply and main board. Initially we thought that the monitor could be used for some hours without too much harm .
Then we have used this monitor for an entire evening, and the next day we have used it for typical day of work at the computer, to write and read text files, and also for editing images and videos.
At the beginning we thought that we could bear the EMF of this monitor, but after a day of work we had to say that the EMF from this monitor was still irritating. The result of using this monitor was a sensation of nervousness and tension, and a bit of the typical sensation caused by high frequency EMF exposure, certainly less than the horrible sensations caused by many other LCD monitors, but we don't have this sensation with our modified LCD monitor.
In conclusion, we have found that our modified LCD monitor is still better in terms of electromagnetic radiation, at least from our sensations, so we have turned back on our latest modified monitor.
We suspect that the EM radiation of this monitor could be reduced a bit by replacing the small switching power supply with a low EMF one, based on linear circuit and toroidal transformer. At this moment we can't do this test but we are going to do it soon. If the replacement of the power supply could bring the EMF at the same level of our previous modified LCD monitors, then this product would surely be a better solution, because of the good exterior appearance, and the high brightness.
Test of a particular LCD monitor with
our low EMF power supply 2012
Electromagnetic emissions of LCD monitors with LED backlight