Night Billboard





Introduction: Night Billboard

Be seen! This will teach you how to make a giant sign that can be seen at night. We will be modifying an old-school overhead projector and using a large wall as the screen. The effect is amazingly professional looking, but the entire project cost only $30.

I built this to help a friend promote her company. Almost immediately after using the Night Billboard, she noticed an increase in business. I am planning on building another one that I will lease out to people wanting to advertise on it. In my town (NYC), even a small ad on a telephone booth can cost $20,000, so I expect that I should be able to make at least a couple grand a month leasing out space on this sign.

In any case, I've tried to be very specific about the parts I used and the necessary modifications. If you build a Night Billboard, feel free to post pictures here ... I'd love to see them!

Step 1: Obtain the Parts

You will need an overhead projector, and some light bulbs of type EVD - 36V, 400W.

For my overhead projector, I found a 3M 9800 series on eBay for $25 with shipping. I highly recommend this model as it has one of the highest lumen outputs making the image extremely bright. It is also designed to be user-serviceable from top to bottom, so if you ever have any problems, it's relatively easy to make the repairs yourself.

For the light bulbs, I googled around a bit and found the best deal on the EVD - 36V, 400W
here. I don't have any affiliation with this site, but I recommend them for low prices and speedy delivery.

Step 2: Install New Bulbs

First, unplug the projector and open the top cover. On every projector I've seen, there is a little button you have to push in on the side of the writing surface. Push this button in and the whole top cover (including the writing surface) will lift off.

You will see the light bulb chamber right in the middle. Lift the lens covering the light bulb chamber and remove whatever bulbs are in there. Remember, to get a bright enough light, we are going to replace the stock bulbs with our new ones.

Carefully insert the new bulbs where the old ones were. Do not touch the bulbs with your bare hands or you will shorten their lifespan. Usually the bulbs will come in some kind of packing material that can be used to help insert the new bulbs without touching them directly.

Close the cover to the bulb chamber, and you're all set.

Step 3: Set Voltage Jumpers

Now that we've installed the light bulbs, we need to set the voltage jumpers to an appropriate voltage for the new bulbs.

NOTE: if you are using a more modern projector, the voltage settings may be determined automatically and the jumper changes described here will not be necessary.

Locate the jumpers on the circuit board. You can see them highlighted in the image on this page.

The jumpers will be labeled. Put shunts on the STD jumper and the US jumper. If you are not located in the US, use the jumper that is appropriate to your country, but keep the STD jumper shunted.

Step 4: Design Your Graphic

Open your favorite image editor and create a new grayscale 8.5" x 11" image with 300 DPI resolution.

Make the background white, and mock up your text and graphics in black.

When you have everything set the way you want it, invert the colors in the image (Ctrl-I in Photoshop) and you should end up with white text and graphics on a black background. When this is printed, the light will shine through the "white" areas and the black areas will block the light.

Put this file on a CD and take it to your favorite printing shop. Ask them to print it on a transparency. The place where I had mine done charged me around $1 for each transparency.

Step 5: Turn It On!

Aim the projector at a blank wall, and turn it on. Line up the transparency so that your image shows up in an aesthetically appealing way, and then when you have it right, tape it down to the projector so it doesn't move around.

That's it - you're done! You now have a billboard for far less than anyone else in town paid for theirs.



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I have the same idea except i would be using an LCD projector and displaying videos... such as commercials that i would sell for advertising space... I know it has been a while but did you ever encounter any legal issues with this and do you think it would make a difference that im playing full on commercials? I am in the bronx area so im hoping you would be the right person to ask.

Hey, thats a great idea of using the overhead projector. I have used one for drawing big images on shirts with reflecting the image at the shirt.

I looked for the bulbs in Germany but I doubt anyone sells them here. And you always talk about "bulbs". Do I need to buy just one ore more then one?

Marco from Berlin

I am interested in leasing out a space and I was wondering: 1-Where do you get the power on the street? (ohp do need a lot of power!) 2-Have you been successful in leasing the space out? 3-Any other thoughts legally (I live in Austin) Thanks!

1) I live in the building upon which the projector sits. So I can easily run a wire up. I imagine you could use a generator if need-be. 2) Yes, but I will not go into details. 3) If you are worried about the legal issues, talk to a lawyer. Out of common courtesy, I made sure the light did not hit any windows or light up the wall outside of any windows. Really, as long as you are not a dick with the thing, I don't think anyone will care enough to put you in trouble. Like I said though, if you're worried about it, talk to a lawyer.

I love this thing! How far will the projector project this image?

I don't know. In mine, it's projecting over a distance of perhaps 40 feet. If you were in a sufficiently dark place, you could project over a greater distance. NYC is bright as shit at night, so I don't think a larger distance will work here. The problem is not just the light attenuation, but also the diffusion that comes from the projected image getting larger. In any case, you should give it a shot and let us know how it goes!

Cool stuff. But why do you have to change the bulb? Wouldn't there already be a 36V, 400W bulb in there? And since the OH is set for those numbers, why do you need to change the voltage? Sorry if my questions are dumb, but I'm a newbie who's just got hold of a OH of 24V, 250W. Would anybody happen to know if it's possible to somehow upgrade it for 400W bulbs?

Well, the higher the wattage, the brighter the image will be. I wanted a really bright and high-contrast image, so I used a brighter bulb. In order to do this, I had to monkey around with the jumpers as described. If you put a higher wattage bulb into a socket that cannot handle it, you might, depending on the safety features built into the projector, have a fire hazard. If I were you, I'd give it a shot with your 250W bulb first and see if the results are satisfactory. You may not be able to tell from the image I used, but the projection is around 50 feet high. To get something this large and have it still be bright, the higher wattage was required, but your project requirements are most likely different. When you do it, post your results - I'm sure we'd all love to see them!

I still don't get why you need to change the voltage on the 3M 9800 which is already made for 36V 400W bulbs, like the ones you got. Or am I missing something?

Sorry, can you explain step 3, as if you were explaining it to a small child? Just need some clairification on "shunt" and "jumper" to see if this is something I can undertake.