robert_stemson Posted November 2, 2006 Share Posted November 2, 2006 Good Morning All! Interesting question here, I am looking to Dim 6 30w Fluorescent Tubes... I have access to Strand Act 6 Digital Dimmers, according to Strands website datasheet. The Act 6 Digital has ' 4 Dimming Curves including Fluorescent with adjustable cut off'. The manual only tells you how to set the dimming curves, Non Dim, Linear, Low Cut off and square law. I have never personnally worked with dimming Fluorescent lights before, but will the Act 6 be able to dim fluorescent and how do I set it up without blowing up the tubes or dimmer!?!? Just to let you know, that 5 are in one circuit and another 6th is on a Single circuit. All I want is the fluorescent to dim, Dim totally if possible or just cut out at a lower voltage rather than having them on a Non-Dim for now.I also understand the flicking at low intensity as I have hired another fluorescent light in for the show which is the effect I require for that unit only. I haven't got the budget to hire more in for the total run...Any Advice will be grateful. Rob Little on the net research... Fluorescent lamps are negative resistance devices, so as more current flows through them (more gas ionized), the electrical resistance of the fluorescent lamp drops, allowing even more current to flow. Connected directly to a constant-voltage mains power line, a fluorescent lamp would rapidly self-destruct due to the unlimited current flow. To prevent this, fluorescent lamps must use an auxiliary device, commonly called a ballast, to regulate the current flow through the tube. If you try to dim fluorescent light on normal dimmer you have to turn the dimmer full on to make the light to turn on and you can only dim it down only down to 30-50% brightness. For anythign less than this you will need a special dimmers and special fluorescent fitting. Linear:The output phase varies linearly with the input (greatest light level variation between 30% and 70% settings) Square: The output power varies linearly with the input (square law ramp standardized by United States Illuminating Engineering Society). At setting of 50% you will see alight level of arounf 50% of maximum. When the lamp is off, the mercury/gas mixture is non-conductive. When power is first applied, a high voltage (several hundred volts) is needed to initiate the discharge. However, once this takes place, a much lower voltage - usually under 100 V for tubes under 30 watts, 100 to 175 volts for 30 watts or more - is needed to maintain it. Link to comment Share on other sites More sharing options...
gingertom Posted November 2, 2006 Share Posted November 2, 2006 I would suggest you give Howard Eaton a buzz, or search for "flourescent dimming" with your friend google inside the blue room. Although I am sure that others have better sources? eg I seem to remember that RJ do a fairly sexy flourescent set-up? (I maybe, and often am, wrong). Link to comment Share on other sites More sharing options...
robert_stemson Posted November 2, 2006 Author Share Posted November 2, 2006 By the looks of things, I believe that I can't just plug and play with a fluorescent into an Act 6 Digital. The 4 types of Dimmer curve is just for the intensity (Voltage) control, So I need to purchase a Ballast to supply the voltage. What would happen if I plug a fluorescent into a Dimmer? Once it got to the right start voltage, will it strike? and then once struck, if I lowered the voltage it would dim till it cut out? The current fluorescents I'm using are modern and haven't got a Starter, as I have no start flicker. So how would this behave under a dimmer, obviously not like an incadencent. Will check out Howard Eaton. Link to comment Share on other sites More sharing options...
back_ache Posted November 2, 2006 Share Posted November 2, 2006 By the looks of things, I believe that I can't just plug and play with a fluorescent into an Act 6 Digital. The 4 types of Dimmer curve is just for the intensity (Voltage) control, So I need to purchase a Ballast to supply the voltage. What would happen if I plug a fluorescent into a Dimmer? Once it got to the right start voltage, will it strike? and then once struck, if I lowered the voltage it would dim till it cut out? The current fluorescents I'm using are modern and haven't got a Starter, as I have no start flicker. So how would this behave under a dimmer, obviously not like an incadencent. Dimming flou's with a leading edge dimmer isn't done any more, now it is done with just power and a control signal and the ballast sorts out the technicalitys. Assuming this is for theatical use, the simplest way is to get dimmable ballast controlled by 1-10v which you can plug into a standard demux, this alone however will not give you blackout at it's minimum it'll be 30-40 percent and you will have to use a switchpack (or dimmer in switchpack mode) to cut the juice if you want blackout. If you want it to go all the way to zero percent without cutting power you would have to go with a dimmable ballast controlled by DSI or DALI and a DMX to DALI/DSI convertor. If you are going the DALI route don't be tempted to put for than a few lights on each DALI universe as it's slow bus speed wil give a visable "mexican wave" effect across the lights. I have no experience will DMX to DALI/DSI converter so cannot comment on them. Link to comment Share on other sites More sharing options...
David Duffy Posted November 2, 2006 Share Posted November 2, 2006 Assuming this is for theatical use, the simplest way is to get dimmable ballast controlled by 1-10v which you can plug into a standard demux, this alone however will not give you blackout at it's minimum it'll be 30-40 percent and you will have to use a switchpack (or dimmer in switchpack mode) to cut the juice if you want blackout. I've used 0-10V dimmable ballasts before and had no trouble going from 0 - 100%. OK, the minimum start and drop out levels are more like 5% from memory but they do definitely turn off neatly *near* zero. Maybe older versions had trouble with this but not the new ones. In a tourist attraction, we used them to turn UV tubes on and off (semi) randomly in one environment. Link to comment Share on other sites More sharing options...
Martin Posted November 2, 2006 Share Posted November 2, 2006 Assuming this is for theatical use, the simplest way is to get dimmable ballast controlled by 1-10v which you can plug into a standard demux, this alone however will not give you blackout at it's minimum it'll be 30-40 percent and you will have to use a switchpack (or dimmer in switchpack mode) to cut the juice if you want blackout. Most dimmable flori's you can hire, have all this built in, which is why they are expensive. They have a demux which feeds the ballast 0-10V and a relay to cut the power when the channel is at zero, so they blackout completely. Of course they still don't fade all the way to zero, but it's good enough for most uses. They fade to a point and then snap off, but there is not much you can do about that. Link to comment Share on other sites More sharing options...
Renny Posted November 3, 2006 Share Posted November 3, 2006 I have no experience will DMX to DALI/DSI converter so cannot comment on them. I bought some kit recently from a German company. DSI ballasts and DMX-DSI convertors. I have to say it is the first time in my life I have achieved good fluorescent dimming. The 1% drop off is still there but you can live with that normally. Also you run off non dimmed mains and just need a DMX cable to the unit so you save on ways of dimming. They come as kits so a bit of knowledge is good in terms of being comfortable wiring from diagrams. Link to comment Share on other sites More sharing options...
david.elsbury Posted November 4, 2006 Share Posted November 4, 2006 What company? I'm wrestling ATM WRT some flouros we have at church. Have built a 1-10v manual dimmer but it doesnt work properly- they only go down to like 30% David Link to comment Share on other sites More sharing options...
Renny Posted November 4, 2006 Share Posted November 4, 2006 What company? I'm wrestling ATM WRT some flouros we have at church. Have built a 1-10v manual dimmer but it doesnt work properly- they only go down to like 30% David I'll post the details tomorrow when I get into work. It is very good kit. Link to comment Share on other sites More sharing options...
Oovis Posted November 4, 2006 Share Posted November 4, 2006 Dimming flou's with a leading edge dimmer isn't done any more, now it is done with just power and a control signal and the ballast sorts out the technicalitys. That's a sweeping generalisation, isn't it? If you stood on my stage I could show you a 5' tube fed from a dimmer in use on our show today :) Link to comment Share on other sites More sharing options...
Steve Adam Posted November 6, 2006 Share Posted November 6, 2006 I'm about to embark on something similar - can anyone recommend a particular brand and supplier/distributor? How much would you guys expect to pay for a 0-10v dimming ballast these days? Link to comment Share on other sites More sharing options...
robert_stemson Posted November 6, 2006 Author Share Posted November 6, 2006 If you stood on my stage I could show you a 5' tube fed from a dimmer in use on our show today What type of Dimmer is that oovis? and how has that been set up? Also What is Swithpack Mode on a Dimmer? Is that setting the dimmer to a certain cut-off Voltage? Link to comment Share on other sites More sharing options...
Oovis Posted November 6, 2006 Share Posted November 6, 2006 If you stood on my stage I could show you a 5' tube fed from a dimmer in use on our show today What type of Dimmer is that oovis? and how has that been set up? It's a dimmable fluorescent hired from White Light, plugged into one of our Permus dimmers. Works a treat. Link to comment Share on other sites More sharing options...
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