High current with Arduino
For thermochromic material as well as for other smart outputs e.g. Nitinol (Shape Memory Alloy) we need more current than the regular Arduino can give. To achive this we use a special circuit. A great tutorial on the circuit you can find under: http://itp.nyu.edu/physcomp/Tutorials/HighCurrentLoads. You will need an extra power supply (e.g. a 9V battery), a transistor (all TIP 120 are ok, I used 150872 - 62 from Conrad and a 1N4004 diode (e.g. 162248 - 62 from Conrad).
March 14th, 2007 at 4:28 pm
Sounds good to me. Does that mean that we will be able to use material that changes its color according to temperature? For example we can create various “pictures” on the material…
I also remember you showed us the nitinol – it was a piece of wire that had to be heated up to a certain temperature and then after it was deformed and electric current was used to shape it back to its original form. Do we have any practical example where this is used?
My only question is what exactly is high current?? I mean in terms of safety – could it harm or hurt a person when not used correctly?
I also like that small white square into which you can plug cables and other electronic devices to test the circuit. It maybe would be good to include these in the Kit. We agreed that planning is a very important part of the whole process of creating something using the kit – this should help the kids to test their circuits before they start to work with textiles.
What do you think?
March 15th, 2007 at 7:00 am
Yes, the material is a fabric that changes color when you heat it up and you could create pictures or pattern. For “high current” I talk about 9 to 12 V. Not more, because as you mentioned – we do not want to risk any harm!
January 10th, 2008 at 8:20 am
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