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November 2, 2005
Build a better mouse trap transparency projector
For many presentations, a LCD projector has become de rigueur for showing charts and text. But in certain disciplines, most notably mathematics and others that are mathematically intensive, the ability to hand-write on the transparency has preserved the transparency projector
as a communications tool.
But have you noticed that these things suck? They draw a lot of power, throw off so much heat that they need a loud fan, and end up almost two feet deep, three if you include the magnifying arm.
I have a simple design improvement. Add a LED lamp to the device.
Rather than heating a filament in an incandescent bulb until it glows, led use ultra-efficient (bright, cool, and long lasting) diodes use the odd behavior of semiconductors to generate light.
All of the sudden these devices don't require a fan or all that space in the device to cool it. The device is now quiet and energy efficient. But is it bright enough?
A typical transparency projector runs uses about 2,500 Lumens. Luxeon Star makes an LED bulb that produces 25 lumens with 1 watt. This requires a 100, for a ridiculous cost of about $1000. But it uses only 27% of the power. But like most things electronic, the prices are falling fast, so sometime in the next few years a compact, quiet, and cool transparency projector will be cost effective.
Posted by OneEyedMan at November 2, 2005 12:42 PM
Comments
Hello
Bit of an odd request, but I'd like to use your image of a data projector in a survey which is going to be sent out to some classroom teachers. Can I please have your permission to do this, or alternatively a link to the original source of the image?
With thanks,
Jessica
Posted by: Formulate ![[TypeKey Profile Page]](http://www.belligerati.net/nav-commenters.gif)
at September 24, 2008 7:53 PM
I think I just found it on the internet somewhere. I don't mind if you use it, but I didn't take it.
Posted by: TheOneEyedMan at September 25, 2008 5:14 PM
In the 3 years since I posted this you could now buy the necessary LEDs for $564.
But now you can buy the Endor Rebel - Cool White, Tri-Emitter, 435 Lumens @ 700mA for $18.50, which means you could replace the old level of white light for $55.50!
Posted by: TheOneEyedMan at September 25, 2008 5:17 PM
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