gareth Posted September 3, 2012 Share Posted September 3, 2012 'Ey up. Got a show coming up in the autumn which needs a quantity of dimmable 4-ft fluorescent fittings. A web search or two has revealed that various manufacturers are now doing a rather nice line in LED-powered substitute tubes for florrie fittings - but as yet, I haven't found one that's dimmable. Anyone know of a company doing a dimmable version? Link to comment Share on other sites More sharing options...
Brian Posted September 3, 2012 Share Posted September 3, 2012 I've been looking for some and haven't found any. Link to comment Share on other sites More sharing options...
timsabre Posted September 3, 2012 Share Posted September 3, 2012 You could simulate it by backlighting a real tube with white led tape... that is dimmable. Looks realistic but not as bright as a real tube.... can be an advantage for a prop. Link to comment Share on other sites More sharing options...
gareth Posted September 3, 2012 Author Share Posted September 3, 2012 You could simulate it by backlighting a real tube with white led tape... that is dimmable. Looks realistic but not as bright as a real tube.... can be an advantage for a prop. Needs to have a similar light output to a standard T8 4-ft tube, so that wouldn't be anywhere near bright enough. Link to comment Share on other sites More sharing options...
timsabre Posted September 3, 2012 Share Posted September 3, 2012 Ah ok, I wasn't sure if it was for lighting or just for effect.The led tubes are not as bright as a proper tube either. Link to comment Share on other sites More sharing options...
Brian Posted September 3, 2012 Share Posted September 3, 2012 You can get tubes designed for an external driver. Example. Coupled with a suitable PWM LED driver/dimmer you might get a workable solution. Link to comment Share on other sites More sharing options...
michael Posted September 3, 2012 Share Posted September 3, 2012 I recently did a show where the theatre had 4 lengths of LED pipe running around the whole auditorium.It was around the same diameter as a florrie tube too. Im not sure who they were made by and at what length you can cut them too but they certainly had the same output if not more than a standard 4ft florrie. Will try to find out who they are made by in the morning. Michael Link to comment Share on other sites More sharing options...
DrV Posted September 3, 2012 Share Posted September 3, 2012 Ah ok, I wasn't sure if it was for lighting or just for effect.The led tubes are not as bright as a proper tube either. If you do end up needing to use real florries Sparks Hire have some which dim down very nicely. Dave Link to comment Share on other sites More sharing options...
gareth Posted September 3, 2012 Author Share Posted September 3, 2012 The Sparks ones are a possibility, I just need to make sure they're suitable for building into a prop shell to make them look like a commercial fitting. It would be a five-week hire, though, and once we also factor in the cost of getting them to north Wales and back it might be more cost-effective to buy some 4-ft fittings and some dimmable ballast. (Anyone got a good source of said ballasts, by the way?) Link to comment Share on other sites More sharing options...
bigclive Posted September 4, 2012 Share Posted September 4, 2012 I'm not sure I'd recommend the LED replacements for fluorescent tubes at all. They tend to have very directional output and are rather dull compared to a traditional fluorescent tube. (Ignore the LED salesmans claims!) I'm also a bit wary of the fact that many of these LED retrofit tubes require shunting out of the ballast in the fitting, thus opening up the possibility of a traditional tube being put back in and failing dramatically. I think in the same situation I'd be inclined to go with standard fluorescent tubes on a dimmable ballast system. But keep in mind that they don't dim with a smooth curve. They tend to light and extinguish suddenly at the lower end of the scale. Link to comment Share on other sites More sharing options...
dbuckley Posted September 4, 2012 Share Posted September 4, 2012 ... it might be more cost-effective to buy some 4-ft fittings and some dimmable ballast. Thats what I do, and just put the cost of the fitting onto the production. Anyone got a good source of said ballasts, by the way? If you don't get a PM from another Blue Roomer "soon" bug me, and I'll pass you the details of a man who has a few, who even shipped a couple out to NZ for me. Link to comment Share on other sites More sharing options...
Glyn Edwards Posted September 4, 2012 Share Posted September 4, 2012 If you don't get a PM from another Blue Roomer "soon" bug me, and I'll pass you the details of a man who has a few, who even shipped a couple out to NZ for me. I've got a quantity of VIP-90 ballasts that I could happily be persuaded to part with :) Price is dependent on quantity and obviously shipping at cost, but if anyone is interested then feel free to drop me a PM and we can see what can be arranged. Glyn Link to comment Share on other sites More sharing options...
gareth Posted October 29, 2012 Author Share Posted October 29, 2012 Well ... we didn't go LED in the end - Glyn sold me some of his surplus stock of VIP-90 ballasts and I converted 14 florries to dimmable. They were actually a nice easy conversion - I wired the lot in 6-core cable, commoning the neutrals and earths at the fitting and bringing the two lives out to separate plugs (16A for heater, 15A for lamp power). They work very well indeed - but they did give me a bit of grief today with the amount of earth leakage we're getting on the heater feeds - after trying them on our DMX non-dims and switched hard power, both of which have RCDs protecting them, I ended up having to move them onto regular dimmers due to the amount of nuisance tripping that I was getting. Even then, I found that they were very picky as to what sort of dimmers I ran the heater circuit from - we have a mix of STM and Permus dimmers, and while they're fine on the STMs, they don't like the Permus cards at all. Anyway, all sorted now! Link to comment Share on other sites More sharing options...
J Pearce Posted October 29, 2012 Share Posted October 29, 2012 The rcd tripping could have been due to you commoning the neutrals. RCDs are looking for current going out on the live and not returning on the neutral. Communing the neutrals means current could return down either neutral path, hence upsetting the RCDs. Link to comment Share on other sites More sharing options...
dbuckley Posted October 29, 2012 Share Posted October 29, 2012 Yep, that's the reason for the RCDs tripping. And, of course, what we have here is a series of widow-makers... Not to mention the potential problem of phase ugliness... The underlying annoying problem is that there isn't an electrically nice connection method realistically possible. I've resurected an old Pulsar (non-DMX - sulk) three channel dimmer into use for fluoro practicals, which when three is the magic number it's just fine. It has a Bulgin eight pin disco socket on it, so a bit of hot ridding (which turned into a minor drama, but never mind that) to get permanent live and the three dimmed feeds onto it and it all works a treat, using disco plugs. But I would like to use something a tad more professional that doesn't cost a firstborn per connector... Another convert to dimmed flouros - yay! Link to comment Share on other sites More sharing options...
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