alistermorton Posted March 31, 2016 Share Posted March 31, 2016 I'm hoping the collected wisdom can help. I've been looking for an LED replacement for the 12V dichros we use in birdies, but I'd like to be able to dim them properly. So a lamp with a built in PSU is of limited use, what I'd ideally like is a simple lamp that expects 12V constant voltage in that I can PWM to dim the lamp. This works perfectly of course with things like LED tape which has no clever regulation built in. The closest I've found to what I'm looking for so far is a 12V spot lamp from CPC but its a) a different pin spacing to the typical MR16 and b) it's a different size reflector (a bit under 2" so not really a problem).. Maybe I'm using the wrong search terms in google. I know a lot of you have been looking at replacing lamps in fixtures with LEDs - have you got any favourites that fit the bill? Link to comment Share on other sites More sharing options...
timsabre Posted March 31, 2016 Share Posted March 31, 2016 Can't be done, at least not yet... The trouble is that high power 12V LED lamps have a driver circuit built in so you cannot just PWM them. 12V tape etc just has a dropper resistor so you can.There are a few dimmable types out there (Philips do some) but like dimmable LED GU10s the dim curve is awful. What you really need is a MR16-sized naked LED (ie LED connected straight to the pins) with an external dimmable driver but I don't know of anything existing like that Also I do not know of any MR16 LED lamps, dimmable or otherwise, that match up to a 50W halogen in brightness. The closest I have found is this one but it is not dimmable https://www.ledhut.co.uk/spot-lights/mr16-led-bulbs/7-5-watt-mr16-led-spotlight-45w-replacement.html Link to comment Share on other sites More sharing options...
Dj Dunc Posted March 31, 2016 Share Posted March 31, 2016 Here we go as an option. http://bigclive.com/happy.htm. PCB available in his shop site. http://bigclive.com/shop.htm Whilst it may need some work, I.e getting some pinspot lensed LEDs, it should give you what you are after. Give BigClive a PM on here and I'm sure he will be able to help out. Link to comment Share on other sites More sharing options...
timsabre Posted March 31, 2016 Share Posted March 31, 2016 Here we go as an option. http://bigclive.com/happy.htm. PCB available in his shop site. http://bigclive.com/shop.htm Whilst it may need some work, I.e getting some pinspot lensed LEDs, it should give you what you are after. Give BigClive a PM on here and I'm sure he will be able to help out. This is nowhere near the brightness of a 50W halogen though. You need about 8 watts of LED for that. Maybe we should ask Alister, what power of lamp are you looking to replace? Link to comment Share on other sites More sharing options...
alistermorton Posted March 31, 2016 Author Share Posted March 31, 2016 I'd pretty much come to the same conclusions in your first post, Tim. I'm aware that what I'm really after is simply a naked LED in a reflector/holder, so I can supply all the drive externally myself. The dichros we've been using for detail light are only 25-35W but occasionally we up them to 50W and I'd agree that the idea that a 5W LED is equivalent to a 50W halogen is marketing boll optimism. 5W LED is about 30W halogen I'd say realistically. Many thanks for your input. I'll keep looking, more in hope than expectation. Link to comment Share on other sites More sharing options...
timsabre Posted March 31, 2016 Share Posted March 31, 2016 I think the term you need to be looking for is "light engine" Osram do this which is a 10W MR16 sized array with integrated heatsink, it might fit a birdie but looks quite deep. It just takes a 350mA constant current drive so you could put a DMX driver onto it. Knowing some other Osram LED prices I suspect it probably costs a fortune though.http://www.osram.co.uk/media/resource/hoverimage/612052/product-image-preveled-cn50-900-g2_24d_40d.jpg Link to comment Share on other sites More sharing options...
alistermorton Posted March 31, 2016 Author Share Posted March 31, 2016 Thanks, Tim. That may be the start of a new search. EDIT: About 15-20 quid a piece those. Link to comment Share on other sites More sharing options...
ocfe Posted March 31, 2016 Share Posted March 31, 2016 Hi AlisterWe've provided a few solutions along these lines for customers using the Soraa Constant Current Light engine which will fit into an existing LV birdie.Beam angle can be changed by a lens which can be 10º, 25º, 36º, 60ºYou can use this 4 output driver to driver 4 independant channels from DMXhttp://eldoledstore.com/collections/constant-current-drivers/products/powerdrive-561-a-50w-constant-current-led-driver We can supply everything you need, give me a call/PM if you need any further info. Mods. I hope this is OK and not too commercial.. Regards,Tim Link to comment Share on other sites More sharing options...
alistermorton Posted March 31, 2016 Author Share Posted March 31, 2016 Thanks - I'll bear that in mind. However, one thing I forgot to mention is that not so much an absolute requirements but definitely incredibly preferable, is that the power to the lamp and dimmer can be supplied from a battery pack. The idea is to use our existing radio RC4 dimmers (or similar PWM dimmer driven off the RC4's DMX out) in trucks or on the revolve where we can't arrange a power cable, replacing the current halogen birdies with LED. A pair of 12V batteries could supply enough voltage for some of the lower power LED coins, for example. This is a long term "it would be nice if" project, not a hard requirement for a show, but all ideas and possibilities are welcome. Link to comment Share on other sites More sharing options...
maeterlinck Posted March 31, 2016 Share Posted March 31, 2016 Another route might be to look at a whole swap for a unit with all the driving built in. Quick a few options here, cost effective. We're using Gantom DMX Spots on a job at the moment and they're pretty pokey. (But no, not a 50W warm white birdie, but saturated colours might be comparible). Link to comment Share on other sites More sharing options...
Don Allen Posted April 1, 2016 Share Posted April 1, 2016 Using my 1/5 or 20% guide, you need at least a 10W led to replace a 50W halogen. These LED PAR 16 are the closest I have seen yet. have not got a sample yet, but they are COB so a single light source, but they are 8 degrees. May be a while before a wide beam range is available. I ended up buying these Mountek RGBW LED Pin Spot to use as DMX foot lights as they were the most compact and were bright enough. They use a PAR36 pinspot housing. These also get used as backlights and sidelights on small stages. Link to comment Share on other sites More sharing options...
alistermorton Posted April 1, 2016 Author Share Posted April 1, 2016 Another route might be to look at a whole swap for a unit with all the driving built in. Quick a few options here, cost effective. We're using Gantom DMX Spots on a job at the moment and they're pretty pokey. (But no, not a 50W warm white birdie, but saturated colours might be comparible). Those look quite interesting. I can see uses for those. Thanks. Using my 1/5 or 20% guide, you need at least a 10W led to replace a 50W halogen. These LED PAR 16 are the closest I have seen yet. have not got a sample yet, but they are COB so a single light source, but they are 8 degrees. May be a while before a wide beam range is available. I ended up buying these Mountek RGBW LED Pin Spot to use as DMX foot lights as they were the most compact and were bright enough. They use a PAR36 pinspot housing. These also get used as backlights and sidelights on small stages. Also interesting, although not quite what I'm after as they're mains powered. But these are all useful ideas - thanks. Link to comment Share on other sites More sharing options...
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