EL Wristo
I got some electroluminescent stuff for an exercise for http://hci.rwth-aachen.de/mcp1314 to play around, which leads to another thing that didn't work well :-)
The goal was to make a tron-style clock/wristband (made your own display out of a plain electroluminesence sheet, which i've forgotten to write first :-). In this first attempt the contacts between wire and electrode doesn't work reliable (especially with just removign the insulator for a small part and pressing this part on the surface (the insulation lift it up again). The rest - peeling of the backside electrode and painting a new one with conductive ink works well, and the connection with larger pads worked well. The arduino at the bottom of the EL Escudo shield just toggles each output pin after each other. The inverter is soldered on the prototype area on the shield, connected with 5V and Gnd on the low voltage - dc side and with the inverter output pins on the high voltage - ac side. Top electrode is connected with the common ground, and the outer parts of the back electrode with the other pin of the ac voltage (always on, to prevent a burn out of the inverter). Switchable parts of the back electrode are connected with different triacs, controlled by the arduino (the pin near the printed letter of each port of the shield).
For a real clock more triacs have to be used, and a smaller inverter is needed. Furthermore, etching the form of the back electrode on one side of a pcb, connect it with vias with the triacs/inverter/logic on the other side of the pcb and apply EL ink and an ITO top electrode would be easier (but EL ink is harder to find than EL foil) and more reliable, i guess.
(Obvious i wanted to paint π and not JT, otherwise i wouldn't kept in mind, that i have to paint mirrored on the backside with the conductive ink:-)
The goal was to make a tron-style clock/wristband (made your own display out of a plain electroluminesence sheet, which i've forgotten to write first :-). In this first attempt the contacts between wire and electrode doesn't work reliable (especially with just removign the insulator for a small part and pressing this part on the surface (the insulation lift it up again). The rest - peeling of the backside electrode and painting a new one with conductive ink works well, and the connection with larger pads worked well. The arduino at the bottom of the EL Escudo shield just toggles each output pin after each other. The inverter is soldered on the prototype area on the shield, connected with 5V and Gnd on the low voltage - dc side and with the inverter output pins on the high voltage - ac side. Top electrode is connected with the common ground, and the outer parts of the back electrode with the other pin of the ac voltage (always on, to prevent a burn out of the inverter). Switchable parts of the back electrode are connected with different triacs, controlled by the arduino (the pin near the printed letter of each port of the shield).
For a real clock more triacs have to be used, and a smaller inverter is needed. Furthermore, etching the form of the back electrode on one side of a pcb, connect it with vias with the triacs/inverter/logic on the other side of the pcb and apply EL ink and an ITO top electrode would be easier (but EL ink is harder to find than EL foil) and more reliable, i guess.
(Obvious i wanted to paint π and not JT, otherwise i wouldn't kept in mind, that i have to paint mirrored on the backside with the conductive ink:-)