Simpler BARE Conductive Paint Paper Houses

Everything should be made is simple as possible, but not simpler.  Albert Einstein

I saw the featured Bare Instructable on building paper houses with a painted circuit that lights the house up in the dark.
http://www.instructables.com/id/Making-a-Paper-House-that-lights-up-as-it-gets-dar/#intro


Christmas was a few days away, and I was thinking of making something for the two grandkids that we could work on together.  They love art projects, and so decorating the finished houses seemed like a great idea.

I had bought a container of BARE conductive paint from Sparkfun  with the idea of making interactive popup pages.  I didn't have much luck in my initial tests, so I just shelved the project.  

I checked out Sparkfun and the paper house kit is about $20; I thought I could whip something together myself.

Step 1: Materials

I gathered up the components listed in the Bare Instructable.  I had everything except for the specific transistor (BC548).  However I had a stock of 2N3904 and 2N3906 transistors I use for robot switching circuits.  I also thought that if was going to do an Instructable, the parts should be readily available from Radio Shack so that no one had to wait for an order to arrive.

I set up a breadboard with the components.  Neither transistor worked with the circuit design given.  After some fiddling around and experimenting, I came up with the circuit shown in the photo.  

There are several variables which affect the circuit: the photoresistor you are using, the thickness of the paint, the leds you are using.

However, using a 10K trim pot seems to give a wide variance in adjusting the sensitivity correctly.

Here's my parts list:
10K-Ohm micro-size potentiometer     #271-0282          $1.69
9V battery snap connectors(5)              #270-0325          $3.69
Cadmium-Sulfide photocells(5)            #276-1657          $2.99
2N3906 transistor  (15)                           #276-1604          $2.99
LED - use 2 - Radio Shack sells various kinds
cardstock to print on
x-acto knife
metal ruler
a self-healing cutting board is nice
cardstock or paper that fits in your printer
ballpoint pen - a dead one works great to score the folds in the paper
snips or scissors to cut leads on parts
Tacky Glue or UHU stick glue
a small screwdriver to turn the micro potentiometer
waxed paper
masking tape

I have included the pdf designs on this page for download.

Comments

[Mic100]

Thanks i lake to :)

[Mic100]

Hi very interresting :)
you know this site, I think it will interest you.
This is a site dedicated to cutting and paper constructions
http://cp.c-ij.com/en/index.html
thanks for your nices idees
Mic

[techiebot]

Thanks. I really like this site: http://www.haunteddimensions.raykeim.com/index305.html
But I haven't tried to create any of the models. Thanks for your link. It has some really cool models.