Andygwk121 Posted March 8, 2009 Share Posted March 8, 2009 Hi all I am trying to create the effect of a flickering tube for an underground subway scene. I would like to be able to have this on the dims. I did a search and found a number of threads about this. So I was thinking of using a 1k dummy load and have the channel on 30% or close so the lamp dose not fully strike. Here's my problem I believe that the tube and the 1k dummy load must be wired in series first of all is this correct. I thought if the dummy load was in parallel it would defeat the point of having it in the first place. If this is correct how would I safely wire a florescent tube and a 1k par in series. Thanks Andy Green Link to comment Share on other sites More sharing options...
KevinE Posted March 8, 2009 Share Posted March 8, 2009 Dummy loads are always in parallel, not series, they're there to maintain a minimum load for the dimmer so the dimmer functions properly and the thyristors fire and latch properly. If you connect it in series, it will decrease the overall load and act like a current limiter...which may or may not give you the effect you want here! This approach may work by experimentation, it may be hit & miss, and the tube may fail mid-performance. Flickering tubes in reality are because they go low-emission and the current is not enough to shunt the starter switch out of circuit, so it's constantly trying to restrike. You may find the flickering you get through a dimmer is more like a strobing rather than the effect you're after. Link to comment Share on other sites More sharing options...
Andygwk121 Posted March 8, 2009 Author Share Posted March 8, 2009 Ah I understand now thanks I Guse the only way to find out what the effect will look like is to test it out. Thanks Andy Green Link to comment Share on other sites More sharing options...
Young Johnstone Posted March 8, 2009 Share Posted March 8, 2009 Just thinking aloud now... but would an Atomic strobe on blinder / spike mode pulsing randomly work. Would have to be hard powered with control via DMX though! Like I say just thinking aloud so feel free to find any flaws in the idea! Al Link to comment Share on other sites More sharing options...
Davethsparky Posted March 8, 2009 Share Posted March 8, 2009 Couldn't you just get a dead flou tube and put it into the fitting so that it does exactly what you want Link to comment Share on other sites More sharing options...
JDP Posted March 8, 2009 Share Posted March 8, 2009 Dummy loads are always in parallel, not series, I am not so sure. If I have bars of ACLs in a rig I want to control seperatly (ie not have 2 bars up at once), then I would series the bar with a 110V bulb (usually stored back stage or in dimmers with blackwrap in the gel frames).... If you parallel a dummy load in the case above, it would send 240V into both units, and all bulbs will explode, as opposed to sending 110V in via series, and the units glowing as they should... Link to comment Share on other sites More sharing options...
The Yellow Transit Posted March 8, 2009 Share Posted March 8, 2009 or you could wire a Fluorscent starter in series with a 60w light bulb, good for a camp fire effect Link to comment Share on other sites More sharing options...
KevinE Posted March 8, 2009 Share Posted March 8, 2009 You may just get it by putting a starter that's too small in the fitting, eg a 60W starter in a 125W fitting. The problem is that the constant flickering will eventually kill either the starter or the tube. Link to comment Share on other sites More sharing options...
AlanB Posted March 9, 2009 Share Posted March 9, 2009 Whilst not being the exact answer to your question, this might prove a possible "work around". The School that I work at part-time have been offered (as a trial) 2foot "Flourescent" tubes that have been (very nicely) modified to contain a large number of White LEDs. They are supplied by www.eastpicadilly.com. The trial is to see:a) Any energy saving advantagesb) How good the resultant light ouput is - our fittings are mostly the 4x2ft ceiling tile units some with and some without diffuserc) How easy it will be to convert the fittings - literally 100s throughout the schoold) General opinions of the product. To make them work, 240v is applied across the fitting (the two pins at each end are connected together). The very sparse instructions say the units can be controlled by dimmers and/or electronic switches. (if I remember correctly). I believe the price is about £18.00 each. As you can imagine the time implications of modifying the fittings is quite large and currently there is a slight problem in that different light fitting manafacturers fit the tube bases at different angles - ie there needs to be two different (at 90deg) pin to LED versions. However it does seem a possible good idea for large institutions and even, possibly use as "practicals" on stage. If there is any more interest I can do some more research, however as a "theatre" employee, my current involvement is as an observer and advisor to the school's contract electrician. Alan. Link to comment Share on other sites More sharing options...
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