Hello All, I hope I’ve posted in the right place as this is a question about flashlights (sort of)…
I have a sanyo xf45 projector, it’s a beast of a thing and according to the specs
“Utilizing four high-output 250 watt UHP lamps as its light source, the PLC-XF45 delivers an amazing 10,000 ANSI lumens of brightness.”
The lamps are held in a small housing (one each) and of course as they are 250 w bulbs there is plenty of cooling. I only use this projector for doing projections on my house at halloween and xmas., so colour of light isn’t fantastically important. It is a bit poor in resolutions as well but I got it cheap and couldn’t afford a 10000 lumen laser projector . So I’m stuck with it… What I’d like to investigate is, could I swap those 250 watt lamps with the head part of an LED flashlight? 10,000 lumens is only just bright enough so if I could also up the lumens a bit at the same time all would be super. So first question is , has anyone done this ? I did search the site but couldn’t find anything similar. Second question is what would be a good “cheap” flashlight to try ? 3000 lumens should be doable but something like 6000 would be extra splendid. I’ve had a look at a load of LED flashlights on Ebay and Amazon and don’t believe for one second hardly any of them can do anything like they say they can… Thanks for reading … Any suggestions ?
Short answer is no.
Long answer:
I’m not sure why you’d use a flashlight head, you’d be better machining a custom LED heatsink and sourcing a suitable reflector.
The XHP70.3 tested here does 8700 lumens at 19A - this is a test bench value and bare LED values, expect up to 10% losses once the light passes through glass/lenses. Realistically, with adequate cooling you could get 6000 lumens out of one of these.
UHP bulbs have a much smaller light source area than LEDs, so (hypothetically) you’d end up with a less sharp image, possibly would be fixed with secondary optics but then you’ll have to design and machine custom parts to hold the optics, and source quality optics from somewhere…
If the custom fabrication of parts and sourcing optics (lens or reflectors), and the inferior focus hasn’t put you off yet, you’ll also likely need a new driver for the LEDs.
Thanks for the reply GravelMonkey.
Well anything more than 2500 would be a bonus so 6000 is what dreams are made of but 4000 would also be a lot more than I’ve got even taking off 10% for losses.
I’m not quite sure how they get the four different light sources to come to a spot but I’m guessing there is already some sort of collection optics. Whether that is tunable or not I don’t know. I have an electronics background and a modest machine shop at home so I could go up the route of making my own module. The problem wouldn’t really be the making , it would be knowing what to make. I also tend towards the do as least as possible for the greatest gain outlook on life. So when I thought I’d need to select an LED, match that with a driver , a reflector and possibly a lens and knowing very little about any of them it leaves a lot to got wrong and someone has already done all that in these flash lights so why reinvent the wheel? I appreciate a lot of what you read about the flash lights and LEDs etc is suspect and thus could go very wrong but it seemed a logical starting point , doesn’t it…
I’ve had a good read about them XHP70.3 in the link you gave me. Thanks for that.
I’ll show my ignorance here… It doesn’t seem too much to get a constant current driver at say 8 amps but even the max rated amps gives over 5000 lumens so should be good enough. I’m guessing I don’t want domed as the domes make it less throw and greater flood and I’d try and get as close to 6000K in colour to match daylight. The heat sink is just as big a bit of aluminium as I can fit in that space with fins cuts all over it, so that seems doable. Tints ? not sure what that’s all about and if I get 6000K is this the same thing ? So reflectors and optics… I might get away without additional optics but I’d have to test it to see how fuzzy the detail becomes. Would you think a fresnel type lens would be the way to go or a normal lens type thing? The UHP bulbs do have a tiny light point but have no optics at all so spread out pretty quickly, thus I’m thinking there may already be a collector in there somewhere. Any suggestions on the reflector ?
Seems a bit too good to be true… I was looking for driver board for the xhp and found this one…
Found these, Seem like a good match to the 70.3 ? Do I go for the OP type or smooth? I know a lot say OP everytime but wont that give you a wider beam due to more bouncing about ? Where do you buy your XHP70.3 s ? On mouser website it ways these modules shouldn’t be hand soldered ? I don’t have much choice there. I know they shouldn’t be touched but will it really destroy them if you hand solder ?
Try to sketch your idea of how to collimate the 70.3 in such a way that is compatible with the original projector and achieves similar intensity. There are lots of issues to deal with, with the most important one being conservation of etendue, which limits the image sharpness you can get as these LEDs are much less intense than the original bulbs. Then there’s the problem of finding and housing the right optical elements.
If you are looking for ideas, the most helpful thing you could do is to share a schematic of the projector you want to modify, only with this information can we propose sensible ideas for what to do next, if anything at all.
Thanks QReciprocity42 . Sounds like I’ll have to take it apart and see what’s in there and how its layed out… Which I knew I’d have to do at some point but wanted a feel for if it’s in the realms of possibility before I did and due to the fact I won’t be able to get it apart for a few weeks due to travels etc… I’ve had no luck trying to find helpful schematics on the google… The manual is pretty good but not good enough for this level of tinkering. Conservation of etendue tricky in deed as even if I can move the LED around and get the same spot size on the LCD panels it still wont have the same angle of hmmm “beams” as the single source would. This is where I was coming from with a Fresnel len really something that could get the LED beam to a single tight spot even with the acceptable losses by having yet another optic in the path. I was hoping someone on here had already been down this path and could give me an indication of how hard or easy it was going to be, and yes I am an optimist 
It is going to be very hard. In order for a less intense source to achieve the same brightness and sharpness, you would need much larger optics that probably won’t fit in the existing housing.
If you enjoy tinkering, then go ahead and try to disassemble and see what is feasible. But it may be difficult to get it working again afterward.
I do enjoy tinkering but have very little knowledge or experience on this topic. The LED light source should be a lot more intense though , shouldn’t it ? If the bulb is 2500lm roughly and the 70.3 can do 6000lm? Maybe it would be easier to build a new projector with a 4k LCD screen and couple of fresnels and a lens or two plus a 20000 lm light source…
Intensity is output per surface area. The LED may have more output, but the light-emitting area might exceed the bulb’s by an order of magnitude or more, so at the end the intensity is still much lower.
Generally the brighter an LED is, the less intense it is. Unless you look at LEDs specifically designed for projectors, which can cost more than $100 per LED. There is a good reason why many projectors use bulbs instead of LED sources…I don’t think modifying an existing projector with an LED is a feasible way to improve performance. Maybe upgrading the driver and the bulb would be better.
Ah I see , yes the intensity thing makes sense now. £100 a pop for an LED that would do the job isn’t that expensive really the bulbs can be around that or more and don’t last anywhere near as long… Would you have any suggestions for reading material on these LEDS? Thanks for you input…
I don’t have any experience with these LEDs, but can share where to find some of them, and it is up to you to figure out whether they can be retrofitted into your projection, or whether it’s worth it. The output for these types of emitters seem to be capped at 5000lm or so.
Look for CFT/CBT90 here: Luminus : Specialty White LEDs
Ah you put a disclaimer in your reply and I was secretly going to blame you for everything 
. Joking of course. I’ll go and have a read , thanks for the link…
Just get a compatible xenon bulb on Aliexpress for like $10 and forget about modding. LED will not work in this type of design unless you want to spend time, effort and expertise to rebuild the entire optical path and driving and error detection circuit, which would cost even more than just buying a brand new projector.
Of course you can experiment and have fun, but be aware of the obstacles ahead.