Use an old overhead, an assumedly broken lcd and a resurrected Laptop power supply to create a portable movie-projection system
Why?What do i need?
-Some form of old overhead projector (highschools & colleges throw these away like its their job) (rpi nixed 12 of these my freshman year)
-An assumedly broken LCD pannel. (really hard to find. a broken lcd comes in 4 variants,
1. the lcd has a scythe going through the physical screen and is useless.
2. The backlight is shot and you can barely see the image (absolutley perfect for this application)
3. It stopped working (either the power supply is dead and you build another one or some silly connector got loose)
4. Theres a dead pixel. chances are some fool will get rid of their lcd because of a dead pixel. solution: man-up and live with it.
-Where to get a pannel lcd. rich neighborhoods, or your college repair shop. Inform someone who knows what their talking about that you desperatley need an lcd for an art demonstration. Probability states at least 1 lcd on campus will fail per unit time
-What about laptops
yes, an old laptop will work (p2 era can play a dvd), but and i stress this, you cant just plug VGA into a laptop lcd. it
doesnt work that way. no it doesnt. lcd's have no standard connection methodology. There are boards designed to do this but they are expensive. so just use a semi-functioning laptop, which can be found at computer parts meets worldwide LINK
if your really in a bind, use a late 90's pci video card. They have VESA pannel ports. these are tricky beasts, but you could run a pannel right out of VESA. Chances are your going to be limited to 8 bit color (dependant on card).
And lo, heres the functional diagram. yep, its that simple. the only quirks are maintaining the lcd a reasonable distance from the hot freshnel lens. this is accomplished with a removeable wooden frame. a small 1/2 inch gap allows enough airspace for a fan to cool the surface of the lcd.
|1.||Layout everything. well first off get the thing working. then rip it apart, and tack extension wires on where necessary (courtesy of andrew)|
|2.||Check if the pannel actually works through the overhead. this is useful for determining orientation of the pannel. Some pannels have a strange type of AG film (anti-glare). fortunatley this stuff comes off with a moiste paper towel. oh yeah it doesnt hurt to project an attractive image.|
|2.||Make a nifty case. I used scrapwood from project ATROPOS some miscelaneous screws and the ever-useful hot glue|
|3.||Grab a fan and a power supply. The power supply from this lcd was missing, but after a quick google it was said to be ~ 14v. thankfully i nabbed 4 defunct IBM laptop power supplies out of the dumpster last year and kept them for safe keeping. unfortunatley they are 16V. well it still worked, at least so far.|
|4.||Add other nifty features||i tacked on a magnet to the base and a seperate one on a wire so the wooden platform would remain on the projector|
Build process images
|Overhead view of projector
Test images on the big screen (DCC 308 @ night time)
Test images (outside)
Rensselaer Polytechnic Institute
Electrical & Electrical Power