balou
500+ Head-Fier
- Joined
- Apr 7, 2007
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You have an opamp, but no resistors, protoboard, solder and solder iron? Well, just draw the whole stuff with a pencil
Graphite is an electrical conductor, but not the best - a 1cm trace with a width of approx 0.8mm has a resistivity of approx 15kR. And half the length seems to have approximately half the resistance. As you see by the use of a certain word in the last paragraph, this is all highly scientifical
By widening the traces, resistance also goes down, as expected. Only problem seems that I can't get the resistance under 1k, even with big black blocks on paper and positioning the test thingies of the dmm close together.
I used a 3B pencil - even softer pencils would probably produce better results. You could also draw a potentiometer, by varying the line thickness maybe even a logarithmical one.
One problem could be the connection between the traces and the opamp. Soldering won't work, because 1. graphite and solder are natural enemies 2. paper hates high temperature 3. this is a solderless project after all
the "apply pressure atop the opamp" method could work.
Also, I don't think graphite headphones, iPods and batteries have been invented yet, so the non-graphite counterparts need to be attached somehow too. Maybe mounting them through hole respectively through-paper will work.
There is still much work to be done on the field of pencil-based circuits, but who knows, this may lead to a new breakthrough in the hifi world
Well, I should go to bed now, I will make some further tests and maybe a first cmoy layout tomorrow
Graphite is an electrical conductor, but not the best - a 1cm trace with a width of approx 0.8mm has a resistivity of approx 15kR. And half the length seems to have approximately half the resistance. As you see by the use of a certain word in the last paragraph, this is all highly scientifical
By widening the traces, resistance also goes down, as expected. Only problem seems that I can't get the resistance under 1k, even with big black blocks on paper and positioning the test thingies of the dmm close together.
I used a 3B pencil - even softer pencils would probably produce better results. You could also draw a potentiometer, by varying the line thickness maybe even a logarithmical one.
One problem could be the connection between the traces and the opamp. Soldering won't work, because 1. graphite and solder are natural enemies 2. paper hates high temperature 3. this is a solderless project after all
the "apply pressure atop the opamp" method could work.
Also, I don't think graphite headphones, iPods and batteries have been invented yet, so the non-graphite counterparts need to be attached somehow too. Maybe mounting them through hole respectively through-paper will work.
There is still much work to be done on the field of pencil-based circuits, but who knows, this may lead to a new breakthrough in the hifi world
