Replacement 8mm projector bulb from super bright LED and old cellphone charger.
One of my other hobbies is small-format film. Showing them, making them, etc. By small-format, I mean 8mm, Super 8, and 16mm movie film.
It started with a $25 8mm projector from a flea market and grew into a small of obsession from there. I bought a few cameras and some films off of Ebay. I had some fun one Halloween showing a bunch of horror shorts to some friends.
One of my better finds was this 8mm-super 8 projector. That’s right. It plays both 8mm *and* super 8 film! If you don’t know the difference, I invite you to skim through [this Wikipedia page.](https://en.wikipedia.org/wiki/8mm_film)
I don’t think there’s anything “magical” about watching something on real film. I find it somewhat comforting that my brain is being tricked by having successive images reflected into my eyes at 16 frames per second and *that’s it*. That’s as far as the illusion goes. It is literally one image coming right after another. Don’t get me wrong. LCD screens and even CRTs are fucking cool. But film is simple and almost primordial. And what illusion there is is fragile. If the film gets jammed it will burn a hole in the frame. Learning to switch reels is a dance considerably more athletic than learning a new UI. It’s like being an auto mechanic, but instead of just fixing cars, you’re presenting a work of art.
And, yes. “I was a Teenage Frankenstein” is art. I don’t care what you say.
Unfortunately, these old projectors use incandescent bulbs that get *really* hot and occasionally explode. That’s what happened to this poor guy. What’s worse is that nobody makes these bulbs any more. You can find them for sale, but they are pretty damn expensive and in very limited supply. So, in my attempt to keep film alive, I bought [this fella](https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_null_2096851_-1) from Jameco Electronics and opened up an old cellphone charger. This is what happened:
You might notice that this LED comes attached to it’s own heat sink. Regardless of the voltage applied, this thing generates enough heat to burn itself out. It’s a good thing the projector has a built-in fan to keep that old monster of a bulb cooled down.
A couple cool things about cellphone chargers: they usually take in 110-120VAC and put out 3-5VDC (perfect for this LED) and they use [PWM](https://en.wikipedia.org/wiki/Pulse-width_modulation), which makes them really small and light.
Luckily the operating voltage for the projector bulb is 120VAC, so I won’t need to do any modifications. All I have to do now is fit a square peg into a round hole.
Basically, I just need to make a nice case for this so it doesn’t hit anything conductive and short out. Those two squares of solder on the bottom left of the circuit board are the AC in, so I need to get . Pretty soon this is going to be a pretty satisfying hack!
Things I Hack 
1) 3-5V is NOT perfect for the LED. LED’s should be hooked up to a current supply, not a voltage supply. You need a constant current source.
2) The phone charger is not small because it uses PWM – it’s small because it’s a switch mode power supply. It’s correct that it uses PWM, but that’s not why it’s small.
So are you saying that the phone charger is not the right device?
Good article and post.
I have a Sankyo Dualux 1000 8mm projector that uses an 8 v. 50 w CXR/CXL bulb. I have been thinking about replacing it with an LED module. Your project may be a simple solution for me.
Have you been using your LED projector and are you satified with its performance?
I haven’t been able to use it extensively because the LED was lost in a pile at the hackerspace. However, I have tested it out and it seems to work alright.
However, I would highly recomend getting a power supply that *matches the rated current of your LED*. The LED I have gets the job done, but you would probably have better luck with a higher-powered LED such as one of these: http://www.digikey.com/scripts/dksearch/dksus.dll
Mine really doesn’t have the range that it had with the original bulb.
Good luck! This was just kind of a brain fart on my part. I think other people will come along who will do much better, especially as the number of working projector bulbs dwindles.
I have an old Sankyo dualux-1000 that plays both super 8 and regular 8 film. I need a bulb, but lost the old. What bulb do I need and where do I find one? Tx
If you want an original, I would go [here](http://www.ebay.com/itm/CXR-CXL-KP-GT-A1-17-8v-50w-ARGUS-SANKYO-Dualux-8-P1500-1000-Bulb-Lamp-Free-Ship-/350503818660?pt=LH_DefaultDomain_0&hash=item519ba7d5a4) or some place like it.
how can i replace a lightbulb from my (slicing thing for 8 mm films or projecter) It is 115-V 30W and has a bayonet base (not the spiral thing for screw in socket).
Huh. Well, that’s a little odd. If you can find a 115V 30W bulb with a screw base, I would just get a screw socket that would fit it and replace your bayonet socket with *that*, if I could.
I seem to remember seeing bayonet base 30W bulbs at a hardware store or something. So don’t give up hope.
Just my amateur opinion. Good luck.
TM, I recommend a good heatsink for that. Even with the fan, it’s probably not enough, and this will also do the trick of keeping that LED alive for much longer. If you find you need more power, look into a LEDengin unit (also available on this site):
http://www.thecustomsabershop.com/Luxeon-star-heatsink–P220.aspx
As for the above comments about the supply not being right for the job, well, it will do the trick, but it isn’t good for the LED. Use a constant current driver (CCD). There are some on that site, but they’re unnecessarily expensive there. There are cheapies available on dx.com for example that will serve you well. You draw the power from the charger, still, but first run it through the CCD. You could also use a buckpuck, but the CCDs are just as cheap on dx.com.
like teslasmoustache I am an artist (i make audioviual installations) one of my current projects is very simular to this one, although would like to replace the lamp of an old slide projector with an LED, and afther that building myself small slide-like-projectors to use in my installations.
but like i said, i’m an artist, not an engeneer and my intrest in all these technical stuff is rather fresh, so yes i’m rather new to all this.
is there a possibility that there is somebody out here able to talk me true this kind of project in more detail (that may be a lot more detail) with the right information (according to use a ccd, heatsink, the right kind of LED, the right power supply etc.). or to recommend other pages/fora/books…. where i might find the information i need as a beginner.
thank you all in advance!
I have a Bell& Howell Autoload Super 8/ regular 8 Movie Projector that I bought New in the 1960’s. I have not used it in 45 years…but would love to convert it to LED or equivalent…so I could once again view old family films. I am not techno-savy…at all. Would need a reputable source to make the conversion…if I could afford the transfer.
I have an Argus 8mm movie projector but I don’t know how to get the bulb out to replace it. Can anyone help me? Reply please to heavenslegend@yahoo.com
Hi all,
I figured someone else was working this problem. I am an Electrical Engineer with a lab and a machine shop who has a reason to create a unique sculpture you might appreciate. I have both 8 and 16mm film I wish to project and convert–happy family memories from the 50s. I have a Revere 16 projector, manufacture circa 1950. It uses a 750W air-cooled bulb. If the film stalls, it melts. I want to be able to stop and look at particular frames fully illuminated. The clutch assembly went south when I was projecting for family. I am tired of this. It is 2014. Technology has evolved. There is a better way. I spent some time thinking about it, did some research and then ordered parts.
The plan is to layout this electro-optic-mechanical sculpture on an aluminum plate in breadboard fashion.
I ordered several different silicon carbide XML CREE LEDs to cover the spectral range from 3000K to 6000K–warm-white to blue-white. These are 3amp surface mount packages with bubble lenses. They are available through Digikey @ 1-800-344-4539. I also ordered the Waldemo-KIT-A1-ND which includes the appropriate current source to light them up. In the end I will probably design my own current source which will include both continuous and pulse mode–I should probably call the manufacturer and have a chat about what they take and still survive. I also ordered the 1066-1097-ND diffuse, narrow focus polycarbonate lens for use with the XML series LEDs–the diffuse LED light must be collimated to uniformly intercept the film frame for uniform illumination and maximum photon efficiency–I plan to mount the LED/lens on a stage so that I can adjust the focal distance to efficiently illuminate 8 or 16mm film. My intent is to be able to both project and record/convert 8 and 16mm film. I could scavenge the projector lens off the Revere, but maybe I will just order the lenses from Edmund Scientific and make my own adjustable projection lens. I will also need a lens assembly which can focus the light after passing through the film onto a 1080p digital movie camera CCD–a digital camera with an external trigger that can be used to synchronize the frame capture. I would use an Omron opto-interrupter to detect the rectangular drive holes in the film and to trigger the camera on the drive hole edge. The interrupter could also be used to trigger the LED in pulse mode. I would have spatial adjustment for the opto-interrupter so that I can center the frame capture/pulsed illumination on the frame. My intent is to use dual stepping motor drives–mount the reels right on the motor shafts–use an off the shelf motor drive/control kit–forward, reverse, speed control, single frame step. Pass the film directly from reel to reel through a guide, in front of the optics and through the interrupter–no routing through a serpentine path. Advance the film with one motor using the holding torque of the other to maintain tension–set the motor current/torque so the motor stalls before the film breaks–a light motor assembly with no gear reduction. I would wish to have a dual film guide which slides laterally across the light path, so it would be trivial to change from 8 to 16mm film.
You can get 1000 lumens continuous from an XML CREE LED, but only with proper cooling will it survive–the cooling of the LED is no small issue. Thermoelectrics? Yes, that could work, but you had better think it through carefully. How about straight up forced air cooling? Yes, that could also work, but again you had better think it through carefully or you won’t remove the heat efficiently enough. This is what I am contemplating.
They are SMD packages, but I wouldn’t mount them on a G10 epoxy PCB–I need better heat sinking than that. I would lay down on the flat surface of a hollow copper heat sink two thin strips of .001″ thick adhesive backed Kapton tape in the location where the LEDs will go–the LED packages will straddle the tape so as to be electrically isolated from the copper heat sink. I would place a micro-dab of Wakefield compound on the bottom of the LED package, and carefully weight it into position straddling the tape, and affix it with micro-drops of 5 minute epoxy which contact the body of the LED case and overlap the Kapton tape to adhere to the copper. Thus the chips are electrically isolated from the heat sink and yet they make superior thermal contact with the heat sink. I would use my SMD soldering iron and a loop to affix wires to the LEDs. I would use a piece of a circuit board as the terminal block for interconnect and strain relief, and wire to a rotary switch so that either of the LEDs could be powered, to change the illumination wavelength band. The entire miniature heat sink assembly would translate laterally so that either of the LEDs could be used as the source of projector illumination. I would flow cooling water through the cavity of the heat sink and have a closed loop with a miniature pump, radiator and muffin fan. That will efficiently transfer the heat.
This is a work in progress, one that I think you will appreciate–an electro-optic-mechanical sculpture of sorts. Please do critique if you wish.
best,
Midnight Brainsmith