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making flouros flicker


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#1 Alex Haspel

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Posted 23 December 2005 - 11:37 AM

hi, just one quick question..

how do i make houshold flouros flicker?
and i dont mean a "wrong shutter angle" -kind of flicker, but a flicker like when the flouro is ignited.
..just like the starter was broken...

can this be achieved by plugging them on a dimmer?

thanks in advance,
alex
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#2 Riku Naskali

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Posted 23 December 2005 - 12:23 PM

can this be achieved by plugging them on a dimmer?

Yes. But it is hard to keep them flickering since they warm up and you have to sort of ride the "hot spot" on dimmer. But it's doable :) I wouldn't try it with electronic ballasts, though.
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#3 Phil Rhodes

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Posted 23 December 2005 - 12:27 PM

Hi,

If you can find a variac (NOT a normal triac household dimmer) you can make them flicker in a somewhat controllable way. You must not use a triac-based dimmer unless it is specifically rated for fluorescents, and I'd be cautious about doing flicker effects even then.

Doing any kind of flicker effect will require a conventional iron-ballast fluorescent, and it'll stress the starter quite heavily. They're not that expensive to replace, though.

We should add this to the FAQ.

Phil
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#4 Shawn Murphy

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Posted 23 December 2005 - 08:46 PM

Might help:

http://www.cinematog...centFlicker.htm
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#5 Lars.Erik

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Posted 29 December 2005 - 12:19 PM

Dimmers are good for making fluorescent blink. The gas never really gets fired up, so it will blink all the time.

One thing you have to remember. If it's a shoot with sound, get the dimmers a long way away from the action area. Because they make a high humming noise when plugged into fluorescent.
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#6 Phil Rhodes

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Posted 29 December 2005 - 01:50 PM

Hi,

> Because they make a high humming noise when plugged into fluorescent.

This is usually a sign that they're not rated for fluorescents. If they're doing that, they're very likely to suddenly go dark.

Phil
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#7 Riku Naskali

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Posted 30 December 2005 - 06:31 PM

I did this with a conventional dimmer, but then again I had no idea it shouldn't be done ;)
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#8 Phil Rhodes

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Posted 30 December 2005 - 06:47 PM

Hi,

Some dimmers will put up with it - the more recent, the more likely you are to get away with it. Very cheap types are unlikely to be properly specified.

So you might have been lucky, and it'll work for a while even if you aren't...

Phil
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#9 Preston Herrick

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Posted 31 December 2005 - 01:29 PM

I've done it by running power through a momentary switch box ("finger powered") with hardare store conventional iron-ballast fluorescents. Had a surprising amount of control with a convincing randomness. The lights are now hanging in my shop.
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#10 Moshe Mishali

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Posted 03 January 2006 - 08:57 AM

there's one more way to make flourcent blink, you can take low watt starter (i think thats what you call it in english) it costs noting - 1/2$ and use it with a bigger watt bulb, let say you take a 40 watt bulb and use with a 25 watt starter then it blink, i've tried it a few times for an hour or so and it worked great.
i did it because the dimmers i had couldn't make the effect.

good luck

mosh
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