Led Lighting

[Kingy 0]

Ok, this is a slim chance.

 

Recently, say over the last 8 months or so, I have been suffering from headaches. Never had them before, other than drink related!!

 

So I went and had my eyes tested, as I wear glasses. No problems there. They even took an image of the back of my eyes for £10 extra. All good, no new glasses needed.

 

Went to doctors, they checked blood pressure and took samples to have checked. All came back fine.

 

Last night, although suffering from a cold, I went and did a small gig. Only a couple of hours following a meal in a hotel function room. Good gig. By the end of the night, I had a head ache.

 

The only common factor I can find is LED lighting.

 

Thinking back, I went and saw some demo's of LED stuff before I bought it...result headache. Now adding more and more together, it looks like this may have happened more regularly than I had thought. It may just be a co-incidence.

 

Point of the post is, has anyone else developed headaches since using LED technology??

 

I have looked on the net, but can't find anything that suggests this is the cause, but I am now starting to wonder? It's not as though I am new to this industry...but I am to LED lighting.

 

Anyone.....??? :shrug:

[Andy Westcott 0]

Can't see how LED lighting could possibly induce a headache - the equipment doesn't radiate anything other than the visible light, so it can't be that.

 

LEDs don't flicker either (depending on their power supply) - unlike old TV screens and aging flourescent tube lights, so I doubt that would be an issue.

 

They differ in one way though, and that's the suddenness with which the light source turns on and off - virtually instant, unlike an incandescent lamp which takes a niticeable time to 'come on' and even longer to fade out once switched off. Could that be upsetting to the eyes in some way?

For an example of this look at the new LED traffic lights - I find the suddenness of the change disconcerting - anyone else notice this? Same with indicators on some new cars.

 

Hmmm...

[Bolan-Boogie 0]

Tend to agree with Andy.

The term LED stands for Low emission diode, hence I think the low emission speaks for itself. Would have thought you would experience more of a problem (if related) with higher powered halogen fixtures.

[Danno13 0]

That would almost be right, except it stands for Light Emitting Diode :joe:

[superstardeejay 0]

I would say that most LEDs flicker at an almost undetectable rate, they are after all driven by microprocessor which has a 'refresh' rate just like a crt monitor or tv.

 

 

[gadget 0]

I would say that most LEDs flicker at an almost undetectable rate, they are after all driven by microprocessor which has a 'refresh' rate just like a crt monitor or tv.

 

And some can appear to flicker more than others (my KAM PAR 56's flicker at 50hz, or at least feel like they do). I guess if the LED side had a capacitor on, the SCR would stop switching on/off and just remain on... ? Don't most triacs/SCRs rely on an unregulated supply to switch off (AC or DC without any smoothing applied to it) ?

 

David

 

[mikeee 0]

After talking to a theatre tech a few weeks ago I can confirm that LED lighting does flicker. Whilst not noticable at the visual level, the eyes do pick up and transmit to brain information outside of the visual. Also LED's "burn" / "glow" at the cold end of the spectrum, unlike normal lamps which are at the other end (they get warm :) ). I personally would not point LED lighting straight into a crowd, but thats my opinion.

[Danno13 0]

They are very peircing to look at.. thats why I don't point LED pars at a crowd.. not sure it'd be quite as bad with the effect type LED lights though.

 

I have had an LED uplighting enquiry that didn't come off, as their photographer said the lights can ruin the photographs.. is this related somehow??

[Andy Westcott 0]

Do commercial LED effects flicker?

If they were powered off a DC supply they wouldn't - surely it's easy enough to design a logic drive circuit that sinks smooth DC rather than chopped DC? I can do that on the bench - why not the manufacturers? Extra components I suppose...

 

Or just feed them with DC chopped at 100KHz or so - you wouldn't detect a flicker then!

 

I dunno - just what do these far-eastern lot dream up, eh??

Edited November 17, 2008 by Andy Westcott

[superstardeejay 0]

Because the LED drive is PWM (pulse width modulation..like switch-mode.) By controlling the brightness of the LEDs with PWM, dissipation in the output transistors is cut to a bare minimum meaning they can be small and therefore cheap. But the drive signal is a pulse train. The frequency is a compromise between pronounced flicker and excessive enery wastage due to capacitance.

 

One of the ways you may be able to check this is to turn on your parcans at about a thrid brightness in a dark room, and stare at the wall so the cans are just visible out of the corner of your eye. Then start chomping on a bag of crisps..any flavour will do..but make sure they're nice and crunchy..McCoys or Ruffles are ideal. You might find that the parcans appear to dance up and down in time to your chewing..that's your eyes reacting to the flickering LEDS beating with your vibrating eye sockets.

 

Worth a try and if it doesnt work then you've at least enjoyed a nice bag of crisps.

Edited November 18, 2008 by superstardeejay

[Kingy 0]

I was actually thinking of the sheer number of flashing LEDs. For example I use two impossileds, nearly 800 dots flashing on and off. No movement, just flashing.

[dj twilight 0]

Hi, i dont think its the leds' giving you a headache mate.

Maybe the workload! Have a day off!!!

[MintyDave 0]

A local family army welfare club where i dj has a big acme led light. This has triggered an epeleptic fit in a young child where all the other lights, moonflowers, par cans on a sound to light amongst other things, have never bothered her in the past

 

maybe a coincidence but food for thought