LED & EMI - Anyone else notice?

[Al and Missy]

The response by HiJoeSilver hits the nail on the head, but fell short of saying this is not EMI, at least not in the classic sense.

The camera is seeing the periods of light on and light off. The camera frame rate is probably 60 frames per second, maybe 30. The pulse width modulation that produces the dimming effect is at a higher frequency to minimize visible effects to the eye so the camera, when scanning the pixels of the detector chip is seeing periods of bright scene when the LEDs are on interspersed with periods of dark scene when the LEDs are off. since light really is an electromagnetic wave, this could be called EMI, but the definition is usually reserved for the radiation interfering with another device's operation. In this case, the camera is simply recording what is actually happening that the human eye cannot see.

In some cases you can see the effect, depending on the pulse rate, by turning your head while looking at the source, like the LEDs, a calculator display or LED signage. The light pulses will appear at different points in space as you turn your head due to the eye's memory effect.

As several others have stated, the LED dimmers may actually be generating some EMI, but if not adequately filtered by the dimmer the most probable effect is noise in a radio, and the strength of this EMI would be well below any applicable safety standards.

Al

[airstreaker]

Sorry, I have been away for the past few days with other business and hadn't had a chance to read through everyone's posts. Thanks so much to those who responded with kindness, advice, tips, links, etc. Notably - alano, HiJoeSilver, 2012FB, mefly2, riffin-rich, crispyboy, cazual6, Alumineer, & Al and Missy. Thank you!

I am learning and it was my understanding that this was a good place to ask questions, even if they may be based on inaccurate assumptions at their foundation.

I don't believe that one should be required to measure the thickness of their skin before partipating in a forum discussing luxury camping trailers.

I'll leave the words of Elwood P Dowd, which I have always found to be dripping in wisdom

"Years ago my mother used to say to me, she'd say, "In this world, Elwood, you must be" - she always called me Elwood - "In this world, Elwood, you must be oh so smart or oh so pleasant." Well, for years I was smart. I recommend pleasant. You may quote me."

[MsTara]

Airstreaker,

Truly appreciate your reply to people's sarcasm and lack of adding anything but negativity. I am going to remember your quote going forward!

As someone who has had cancer in the past and have removed so much "health concerning items" from my life, I was not aware of the LED issue and EMF. Thanks for bringing the information to the forefront.

Tara

[airator]

Would like to add my vote (to support) the discussion on the subject of LED and EMI/EMF. Just did a quick search on the internet and the level would be too low to pose any health risks, one article for example indicates that the electric cord of an electric razor generates far more potentially dangerous EMF, especially close to the body. Nevertheless, many serious articles point to the fact that indeed, more research is needed on the health effects of EMF, particularly for young children.