My first video projector. Ever.
Last year I came across a cheap Toshiba TLP T70M projector on some e-bay wanna-be site over here in Romania. It had no lamp at all but other than that it was operating properly (or so the salesman told me). I traded it for a Shuttle computer I had in my closet and in a few days the projector was delivered. I was surprised that it was in a good condition, I was expecting cracks and scratches, it had none. I turned it on and - predictably - the “lamp missing” LED came on in about two minutes. At this point the projector shuts down automatically. During those two minutes I was able to see the startup screen by looking thru the lenses while holding a small flashlight where the bulb was supposed to be. So yes, it was operating.
I started google-ing all I could find about this projector. I came across the complete Toshiba TLP T70M user manual (it had none when I received it) and that’s about all. At this point I wasn’t really decided what to do, I was tempted to buy a light bulb for this model and use it as anyone should. On the other hand being horrified by the huge price that projector bulb had it was clear I had to find an alternative light source. Me being a LED addict I started thinking about that. It was the obvious choice but the problem will be the light output. The projector’s lamp had 2000 lumens and in “eco-mode” had 1000 lumens. I was aiming for his lower figure as I won’t be using the projector in daylight anyway. So my goal is 1000 lumens of LED light.
Insert a few weeks of random ideas and pointless calculations here. Lazyness, to be more precise.
Step 1: Parts used
I decided I will buy the most powerful LED I can get my hands on and try to use it as a light source in my projector. All this without being distructive or making irreversible changes to the projector. Google that and it turned out my only choice in power LEDs (over here, in Romania) was a Cree MC-E M, Star, White, 752 lumens output, 4 chips, 110 degree (light beam). I was hoping for a OSRAM OSTAR rated 1000 lumens but the reseller couldn’t provided it.
The original projector lamp had 2000 lumens and 1000 lumens in eco mode. I figured if I get close to that eco-mode it might be usable in my tiny apartment. This LED is rated for 50.000 hours of operation and is considered equivalent with a 75W incandescent bulb. I also ordered a 700mA constant current power supply to power it. This one is rated up to 30V DC output @ 700mA and is powered by grid power (220V AC here). I plan to hide it inside the projector once the project is successful. But enough daydreaming.