Colin-JB wrote:I had an idea I wanted to try regarding NBTV projection. One of the first things I wanted to try was seeing if I could project a standard 35mm negative using a lens I picked up on Ebay. To do this I needed a really bright light so I looked towards my old 8mm film projector. Of course it hasn't been used in a while and the bulb had blown. I have some white LED's and I figured that maybe I could rig one of those into the projector just to see if is was bright enough whilst I sourced the real thing. However, as I have learned in the past, LED's have a + and a -.
So I have a couple of questions, how can I work out which connector on the projector is + and which one is - to put a suitable LED in and what problems might occur if the Voltage of the LED is lower/higher than the original bulb?
Colin-JB
Hi colin
I have been thinking of this as well .
I did just buy 2 lasers one a blue and one a green laser both 50mv the green i have tried with out the lens and its light is like a really really bright torch
With out the lens it or it can be screw adjusted in and out of focus
http://cgi.ebay.com.au/ws/eBayISAPI.dll ... K:MEWNX:IT
Thats the blue one i have just did a quick test on my sstv project saves me focusing but would like the focus of the dot smaller ..any way look for the green version both the lens comes off via the case unscrews .
I am sure some projection could be done with these buggers trouble is the colour ! good for just nbtv projects but flim projecting wonder it i mixed those 2 with my red one i would get white light mmmmm
For the NBTV side for the laser have to pwm them 2 circuits are on the forum one is steves .
You might like to try a few luxeons they are getting cheap on ebay as well lucky for me in Austraila we are close to china so the seamail free post is not to long.
If you just want to project that 8mm flim or 35mm slide my old 16mm flim projector light went and i just used one of those 240v down lights in the reflecting case you can buy any where that worked perhaps half as good as the giant light that was in it before ...but remember that gives off heat my flim was moving so dont have it to close to the flim when stopped .......melt is all i can say but i think you are just using the old projector so that should be ok.
you can not just connect up the led or leds to the projector power supply thats 240v or what ever you lot use up over !!!!
could do that with the 240v downlight but remember buy the 240v version not the 12v ones !
Then its just a matter of mounting and connecting it safely ...lots of ways of doing it ...good luck Colin