For valentines day I decided to make my valentine a picture frame that slowly pulses on and off (like a heart beat) when it is picked up. You can use the same tequnices to make a pulsing light effect on other projects like a computer case mod. Swap out the heart shaped frame for the shape of your choice and the red LEDs for your favorite color.
The frame is made with two small pieces of plexiglass. and the finished frame is no bigger than 5.5" but could be made to any size. LEDs inside light the bottom larger layer of plexiglass. The light will catch on anything that gets in its way between the LEDs and the edge of the plexi. I etched a message in the border which then becomes easily visible when the frame is lit.
The circuit I hacked together from some other more complicated designs is enterally analog and requires no voltage regulation. This means that the circuit should last a long time on a single 9v battery because the 555 timer chip is running directly off of the 9v battery and can continue to use the 9v as a power source as it falls well below the the 9v value. It should continue to work all the way down to ~4v as the 555 only needs 3.3v minimum and the led's only need ~1.4v . A micro switch underneeth turns off the pulsing effect when not in use and the frame is only turned on when picked lifted off of the surface it is resting on. This means it further saves power by only operating when someone is holding it and looking at it. Other modifications could easily be added to make it light sensitive or moation activated as well.
All of the electronic parts necessary should be available at your local electronics store as well and only basic soldering skills are needed to assemble it.
Step 1: What you need...
You will need only a minimum amount of tools and materials to create this project. I used 1/8" plexiglass I believe that I had in my garage. Beyond that you will need a picture, photoshop is good to use because you can easily scale and play with the layers. You will also need a project box, a 555 timer, a 100uF capacitor, a 100 ohm resistor, a 500 ohm resistor, a 9v battery, and a few small other parts like a switch and proto board to put everything on.
The key to the circuit is using a 555 timer to create a slowly fading in and fading out pulsing effect wile not going completely dark. I have tried many different pulsing circuits until I found one I liked. I then modified it until it had the fewest parts possiable. You could make it without the pcb if you wanted and just solder the parts together. (pcb posted soon)