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Topic Title: High Frequency Fluorescent light
Topic Summary: and interference
Created On: 15 April 2015 09:06 PM
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 15 April 2015 09:06 PM
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Zs

Posts: 3830
Joined: 20 July 2006

http://www.lyco.co.uk/advice/h...-lighting-what-is-it/

hello, the above is one of many sites for high frequency fluorescent light.

The shed, of course..

I'm just reaching the point of considering the lighting and because I'll be spending quite a bit of day time in there with the laptop on multiple monitors, using Auto Cad and various bits of software I'm trying to be sensible about what I sit under. (Haven't got the laptop yet but that's going to be so that I can bring it indoors with me and is having to be made to order).

It will not be LED. Take that as a given, I detest the stuff and think it is less than healthy but I'll not go on about that.

So, I'm giving some thought to high frequency fluorescent with as much of the daylight quality as I can get. I saw some of these at one of the shows last year and some in a design for a hospital.

So the question is for the health conscious and audiophiles amongst you.

I've not seen any reports of this being suspected as bad for health/general wellbeing unless you use them late at night and then try to get straight to sleep.

I've not seen any reports of them interfering with sound quality but my instinct tells me they ought to cause interference. Eventually I'll be recording simple stuff but nothing major, just backing tracks to play over. However, I'd like it to work.

Any experience?

I'll include some ordinary mellow lighting for the evenings, maybe a desk lamp or the like.

Wellbeing and white noise are the things I'm not finding enough to read about. I asked an expensive lighting designer about it yesterday and he looked at me like I was an alien.

Zs
 16 April 2015 12:14 AM
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westfield6

Posts: 210
Joined: 12 October 2007

Maybe radio interference. Harmonics of 30kHz could affect LW and MW. Maybe suppression is good, maybe not.
 16 April 2015 12:36 AM
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mapj1

Posts: 9707
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I'd suggest making provision for filters and supression is always good, unless you are designing to cost or have problems with high earth leakage.
You may be fine, but odd audio buzzes and feezles at low level can result from the inter-modulation (difference frequency) when two lamps at almost the same hf frequency are in use, even though the supply switching frequency of each one in isolation is supersonic. Wiring segregation is your cheapest friend - keep audio cables, especially mics and pick-ups well away from switching stuff. Failing that, shielded cables. But leaving a space for a box with something like this , http://www.rapidonline.com/pdf/398696_da_en_01.pdf
and having the links ready to add just in case will be easier than trying to get one in later if wiring was not done with separating clean and dirty in mind . And nearby short wave listeners and radio hams will also appreciate it too.

-------------------------
regards Mike
 16 April 2015 08:11 AM
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rogerbryant

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Candles are restful and tend to generate very little EMI (except in the infra red) ;-)

Best regards

Roger
 16 April 2015 08:24 AM
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Zoomup

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What's wrong with nice constant output L.E.D.s Zs? Or just cut a big hole in the roof and have a roof window, or light pipe. I would. Natural light is best, perhaps with a roller blind type thingy for sunny days. I don't really like the high frequency vibrating electron stuff. I have a natural fear of it. Light is already vibrating stuff so why modify and corrupt it further? Enjoy it in its natural form as we have done for years. You could try tungsten lighting via suitable dimmers. Nice constant natural light and no flicker.

Bye,

Z.
 16 April 2015 08:34 AM
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AJJewsbury

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It will not be LED. Take that as a given

Please forgive me for going off at a slight tangent - but I wouldn't want you to throw the baby out with the bathwater with this one. LEDs in principle (being diodes) are naturally d.c. devices and should therefore provide an entirely flicker free constant light source - just because early implementations had pretty shoddy drive electronics doesn't mean that the entire technology is suspect. Likewise the spectrum produced is a feature of individual implementation details rather than a basic feature of the technology (I think some white light sources use phosphors - not unlike fluorescents).
- Andy.
 16 April 2015 09:25 AM
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impvan

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Which is more likely to radiate EMI?
A high frequency LED inverter, SELV but in a plastic housing; or
a high frequency Fluorescent inverter, higher voltage but inside a metal fitting...

It would be florry for me every time. If you can't tolerate the gappy spectrum of standard tubes (and LED is even worse than that), then 9xx lamps are the way to go. You don't get nearly as bright an output, but it's more even across the spectrum.

I changed a local needlework factory over from 835 to 930 lamps - at 700Lux on the worktables, they were struggling to distinguish shades of green.
 16 April 2015 09:32 AM
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OMS

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I'm just reaching the point of considering the lighting and because I'll be spending quite a bit of day time in there with the laptop on multiple monitors, using Auto Cad and various bits of software I'm trying to be sensible about what I sit under. (Haven't got the laptop yet but that's going to be so that I can bring it indoors with me and is having to be made to order).


What do you normally do for your clients - if you are happy for them to sit under your design solution, why wouldn't you be ?

If you haven't yet gone for industrial chic, then how about a barrisol ceiling panel, HF lamps in a range of CCT's above and a bit of simple control that ramps up specific lamps so you get (via the barrisol) almost complete full spectrum output.

Regards

OMS

-------------------------
Let the wind blow you, across a big floor.
 16 April 2015 10:22 AM
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Zs

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Thank you.

the LED thing...If you hold the sleeve of your leather jacket under an LED you can make out the grain very easily. draw the sleeve away and the definition disappears within a couple of feet. With Tungsten halogen, you can get right down to the desk and still see the grain. With Fluorescent, not bad but different spread of light, not so focused. Not as good as TH for keeping sight of the grain though. However, TH lamps get hot so I'm trying to stay away from them in a wooden construction you see.

For my clients OMS, I have a sample board of switched downlighters on a plug which I prop up on a couple of pairs of steps and leave with the client, and a 6 foot Florry, likewise. Most of them are going for downlights of course but very few go for LED in an office environment. I have an LED over my cooker. Food looks better once it is away from the LED. Personal choice really, just not for me. I think our teenagers, currently studying under LED at their desks, are going to be at the optician sooner than the rest of us were (mid to late forties for most of us getting reading glasses?). One of the thorlux range which I saw was fantastic though. Sadly way over budget.

I have a client who has that medical condition where you are always tired (ME?). I put high frequency in her kitchen and she loves it except for finding it too bright in the evening if she just goes to get a cup of tea, but fine if she's accustomed her eyes to it as it gets dark.

Mike, I like that idea because have power-logger can investigate and I plan on surface mounting in compartments. Running the broadband and TV cables today.

You've got some memory OMS...I love barrisol panels. probably to much expense for now but you have started another thought process. I'd forgotten about those.

I had a thought in the wee small hours about HF fluorescent on a complete break switch so that I can completely disable it for making music. I'm also concerned about the 300 frequency of them. But I can log it as it progresses and that wouldn't be a bad call for all of us. I saw a chart of harmonics on Compact Fluorescent a while back and it was alarming. Quite tempted to separate it completely into a separate trunking now, and make it so that I can remove it pronto if required.

I realise why music studios are so gloomy (cosy) compared to offices. Tricky to strike a balance. But I'm working on a gut feeling here.

Thank you for those. I'll keep looking for evidence and not make any decisions for a while, I'll get the work lamp out of the garage to keep me going.

Clean earth is unlikely here, small homes, close together, PME. I doubt I'd achieve anything from the effort.

Zs
 16 April 2015 05:46 PM
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OMS

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You've got some memory OMS...I love barrisol panels. probably to much expense for now but you have started another thought process. I'd forgotten about those.


OK - so in the same vein as using a bit of fabric to create effective acoustic absorbers, hen you can use a bit of fabric to create a very effective barrisol panel - it's what you put behind it is the trick.

If you use a number of HF fittings with a range of lamps then (in combination) they collectively provide light through a much wider spectrum than a group of identical lamps.

The fabric panel will mop out a lot of output and a simple dimmer will give you control over the lux on the desk

Clean earth is unlikely here, small homes, close together, PME. I doubt I'd achieve anything from the effort.


TT the shed at the load end ?

Regards

OMS

-------------------------
Let the wind blow you, across a big floor.
 16 April 2015 07:19 PM
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HarryJMacdonald

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If you are using Laptops & screens you need to make sure the lighting isn't too bright. I remember control rooms for Power Stations were always specified as needing 300lux, and when they went into operation, the operators took out 2 out of 3 lamps to keep the brightness down!
You may need bright lamps to look at drawings but a good 'Anglepoise' will cater for this. Probably best to use a TH ordinary lamp look alike if you don't want to risk rf interference. I bought some LED downlighters for my sisters kitchen and she can't listen to DAB radio when they are on.
 17 April 2015 12:54 AM
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mapj1

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When we get desperate for low noise instrumentation (emc test chambers and so on) nothing beats filament lamps run off DC, with the DC derived from mains outside the clean zone and then brought in through heavy filters in metal filter tanks back to back on the bulkhead. However its more than you need and
"An EMC chamber"
is not what you want the shed to look like I suspect ;-)

mind you, taste is a funny thing. You'll never get me near a leather jacket, I think I'd rather wear a bow tie, but only just.

-------------------------
regards Mike


Edited: 18 April 2015 at 04:45 PM by mapj1
 17 April 2015 02:22 PM
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Zs

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yeah, but you're clearly not a rock chick Mike

I've just committed to a 3 m length of Denzel Univolt three compartment dado trunking for starters and lots of sockets to include the lights. I'll grow it from there. Did you know, they don't actually fit into a Vauxhall combo? Oops, they look like they do, until you slam the back door. Autoglass appointment booked Hey ho.

I'm going to do what you suggested and get lots of geeky measurements as I grow it. But yes. monitors don't half have some glare. As before, I think they keep us awake while we are working but that is another of my hobby-horses Harry. Work late, can't sleep (clowns will eat me?). Missing OMS's avatar like mad.

Expect updates as the power logger teaches us what it is all about. I am simply loving this project.

D-10 mins for the carpet fitter....

Zs
 18 April 2015 04:47 PM
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mapj1

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yeah, but you're clearly not a rock chick Mike

Indeed - though I think you must be the first to realise this, or perhaps at least the first to point it out in such a merciless fashion !

-------------------------
regards Mike
 18 April 2015 05:11 PM
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sparkingchip

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I believe I sat next to the jacket mentioned above during the Elex Coventry IET discussion forum, however I was too busy asking JP and the rest of the panel about the progress of third party certification to look at the grain of the leather.

Regards lighting, I try to avoid dimmers preferring to use straightforward switching options. I looked at yet another blown dimmer this morning that has four GU 10 halogens controlled by it, I swopped it for a ordinary switch and the lady told her husband he will have to get another as now it is too bright, so that will be the fourth. Though one did blow after a Speedfit plumbing fitting came off a chrome plated pipe, I swopped that fitting for a compression one. So really it will be the third, older dimmer switches had fuses in them, but they seem to have disappeared in favour of more electronics.

Andy

Edited: 18 April 2015 at 05:19 PM by sparkingchip
 18 April 2015 05:18 PM
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sparkingchip

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I just Googled Barrisol this has the makings of a real party shed

Andy
 20 April 2015 02:34 PM
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AJJewsbury

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the LED thing...If you hold the sleeve of your leather jacket under an LED you can make out the grain very easily. draw the sleeve away and the definition disappears within a couple of feet. With Tungsten halogen, you can get right down to the desk and still see the grain. With Fluorescent, not bad but different spread of light, not so focused. Not as good as TH for keeping sight of the grain though.

Very interesting observation. I wonder what makes the difference. Being photons are photons, I'd guess it's some feature other than the type of source itself - perhaps spread (narrower beam so less reflecting from side surfaces so light levels decline somewhat closer to inverse square law than otherwise) or something to do with the spectrum and perception at different light levels? I would be interesting to get to the bottom of the differences.
- Andy.
 20 April 2015 04:35 PM
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potential

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In my shed I use metal halide lamps because they throw out next-to-no heat and give a very bright light with a reasonable spectrum.
Not for sitting down relaxing or using PC but very good for detailed work, large or small.

Cheers me up in the winter too, just like sunlight.
 20 April 2015 11:08 PM
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stateit

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I had an interesting chat with a customer trying to decide if EMF will be a 'deal breaker' on their prospective new 'dream home'.

It's adjacent to a hospital and the substaion is fairly near it. And in their reseach subsequent to this they discovered underground HV feeds run right past their house.

They were talking about lead shielding paint on walls, DC feeds for lighting and wired phone/data points to each room instead of wireless.

Some people take it very seriously... What they they want is the best environment for their young child. I'm waiting to see if they will buy the house once they've interpreted the results from their hired EMF meter. I kid you not.

[edit] Makes me wonder what self-inflicted radiation I live in [/edit]

-------------------------
S George
http://www.sg-electrical.com
 20 April 2015 11:38 PM
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sparkingchip

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IET » Wiring and the regulations » High Frequency Fluorescent light

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