How to Use an Overhead Projector as a Computer Monitor

Having a projector to watch movies is great, but they can be very expensive. These instructions will show you how to make an overhead projector (like what you may have used in grade school) usable with a computer. The total investment will vary, but it's definitely possible and probable that it will be much less than buying a projector at retail price.
                          
Since each projector and monitor are different, prices and designs will differ. I will try to make the instructions as general as possible. I used an old Hitachi monitor and a Apollo Horizon Ultra overhead. I managed to get everything for free, and the same could apply to you! This project could take anywhere to a few hours to an afternoon depending on your specific situation and how much time you put into your fixture. The required skill varies from very little to experienced with electronics depending on if you can have the original power supply to the monitor and if the cooling fan needs to be soldered to a power supply.

Just keep in mind that the projector will be far from HD, but its a fun project and most people will find that the benefits outweigh the costs.

Step 1 Gather Materials

What you need:
       - Overhead Projector
       - LCD Monitor, as close to the size as the projector lighting surface
          if the backlight is broken, that's fine. But everything else better work.
       - Either the power supply to the monitor or two wires, better too long than too short. If no power supply, you'll need a power supply with the same specs.
       - Fan (a small cooling fan, not a house fan)
       - Soldering iron, solder
       - Screwdrivers, both flat and Phillips head. You may need small screwdrivers depending on the monitor.
       - Some wood, or any other material to construct a fixture for the electronics
       - Saw. I used a "Saws-all", but any kind shoul do the job.
       - Drill and drill bits. Screw sizes vary, but they will be small.
       - Countersink (optional)
       - A box of screws, possibly several kinds depending on the appropriate fixture
       - Depending on how you secure the fan, you may need a router.

Comments

[Daddio_UK]

There are programs you can run on your pc that will swap the image round the right way.

[ajfitz]

Ha yeah, I was just too lazy to search for them. That's a good point, that the mistake can be fixed after the fact.

[Daddio_UK]

Seen a couple of these on this site, fancied giving it a try but how bright is it?, is it as bright as a comercial projector?

[ajfitz]

That's a good question. I think it changes with with the type of projector you plan on using. I ran mine, and it meets my standards. As far as comparing with commercial projectors, I doubt it's as bright. But I think the photons per dollar on the "homemade" version is pretty good. (There's a picture in the intro with what it looks like on the wall)