EL lights are capacitors which run on specific AC frequency (or the color changes) and not DC.
So wouldn't the ITO layer work as a faraday shield? 3 layer capacitors are used as filters
with the middle layer grounded. Could they spontaneously change capacitance if left floating?
It seems to me they are insulators but could they still be photosensitive in some way?
I'd guess that even incandescent lamps change (resistance) detectably when exposed to external light.
Suggestion: If you have a worn out PDA, (dead or leaked battery) then disassemble the screen
to experiment with.
Also, I know some kinds of antistatic bags are conductive.
Of those that are not opaque, I think the red-pink ones are and some which look like polaroid.
I'll go test some.
Other ideas... have to get back on this one...
I have somewhere instructions how to make solar cells as a science project, in various ways.
An at least moderately hard way I recall involves thin film silver deposit precipitated by ammonia or something,
and I think it gets washed just before it's opaque, because it's supposed to be solderable and transparent
to an oxidized sheet of copper so light can get to that layer. If I find that I should post the method.
It may be hard to do but the idea would be have invisible touch contacts to measure (skin) resistance
between them above every LCARS "icon".
People are magnetic. I'm eccentric enough to have had a train of thought leading up to the experiment
of using an old surplus multitrack tape head to record sound on my arm, which lasted about 12 hours
until enough blood had left the capillaries in my skin. The magnetism is so weak that I connected
the tape head to an amplifier's loudspeaker to record. Then I connected it to the mic input and
turned it up to eleven, and I could hear fluttery tones by swiping the tape head on my arm.
An alternative method is somewhat Theremin-like, using a simple pair of air core coils (like
Parallax RFID sensor board?) and the coils connected like a joule thief. Actually no resistors
are needed; base and collector go to single wire of coils, around half a volt between emitter
and double wires (common) of coils. Adjust carefully, this may work at around 0.3 volts.
The oscillator is a reverse VCO in it's range but at highest pitch is very sensitive to metal
I think, and skin is not only slightly ferromagnetic but also para or dia magnetic. A piezo
can be used to test for tone across the coils. Who knows why, IIRC, this might work,
but the disadvantage of it is making several with similar characteristics to be used
as a control panel, or the pain of programming a calibration setup to determine the
frequency range of finger detection for each coil-transistor oscillator.
There are lots of ways to do it.
Did I or someone mention IR emitter/detector beam interruption?
I have noticed some things all of which are visibly black have different reflectance or transparency to IR camera,
so the detector pairs could be concealed behind IR transparent "black stuff".
Afterthought: Tape heads. Probably many of you haven't played with a tape recorder but I noticed if I
touch the tape head there is a whooshing sound meaning that some magnetic flux must be picked up.
I'm not sure if it's range is 1/4 inch though, unless perhaps much more amplified. If tape heads were
available as surplus by some chance, or something similar, then perhaps an op amp could make a
significantlt consistent detection pulse.
Comments
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3 inch x 1 foot size piece of el sheet(split electrode) is $19.95
4 inch x 5 inch size piece of el sheet(parallel electrode) is $18.56
So wouldn't the ITO layer work as a faraday shield? 3 layer capacitors are used as filters
with the middle layer grounded. Could they spontaneously change capacitance if left floating?
It seems to me they are insulators but could they still be photosensitive in some way?
I'd guess that even incandescent lamps change (resistance) detectably when exposed to external light.
the Photo-electric effect.
But I noticed that using it to detect light for this use wouldn't work so well. (shadows)
Hmm, i just looked up the ITO film and it seems thats the expensive part.
http://en.wikipedia.org/wiki/Indium_tin_oxide
The only way to know how/if this stuff works is to try it.
buying a few of the el sheets isn't too bad, but purchasing many would add up.
Thats where using just ITO film might be the cheapest route.
Post Edited (Clock Loop) : 10/27/2009 10:05:04 AM GMT
to experiment with.
Also, I know some kinds of antistatic bags are conductive.
Of those that are not opaque, I think the red-pink ones are and some which look like polaroid.
I'll go test some.
Other ideas... have to get back on this one...
I have somewhere instructions how to make solar cells as a science project, in various ways.
An at least moderately hard way I recall involves thin film silver deposit precipitated by ammonia or something,
and I think it gets washed just before it's opaque, because it's supposed to be solderable and transparent
to an oxidized sheet of copper so light can get to that layer. If I find that I should post the method.
It may be hard to do but the idea would be have invisible touch contacts to measure (skin) resistance
between them above every LCARS "icon".
People are magnetic. I'm eccentric enough to have had a train of thought leading up to the experiment
of using an old surplus multitrack tape head to record sound on my arm, which lasted about 12 hours
until enough blood had left the capillaries in my skin. The magnetism is so weak that I connected
the tape head to an amplifier's loudspeaker to record. Then I connected it to the mic input and
turned it up to eleven, and I could hear fluttery tones by swiping the tape head on my arm.
An alternative method is somewhat Theremin-like, using a simple pair of air core coils (like
Parallax RFID sensor board?) and the coils connected like a joule thief. Actually no resistors
are needed; base and collector go to single wire of coils, around half a volt between emitter
and double wires (common) of coils. Adjust carefully, this may work at around 0.3 volts.
The oscillator is a reverse VCO in it's range but at highest pitch is very sensitive to metal
I think, and skin is not only slightly ferromagnetic but also para or dia magnetic. A piezo
can be used to test for tone across the coils. Who knows why, IIRC, this might work,
but the disadvantage of it is making several with similar characteristics to be used
as a control panel, or the pain of programming a calibration setup to determine the
frequency range of finger detection for each coil-transistor oscillator.
There are lots of ways to do it.
Did I or someone mention IR emitter/detector beam interruption?
I have noticed some things all of which are visibly black have different reflectance or transparency to IR camera,
so the detector pairs could be concealed behind IR transparent "black stuff".
Afterthought: Tape heads. Probably many of you haven't played with a tape recorder but I noticed if I
touch the tape head there is a whooshing sound meaning that some magnetic flux must be picked up.
I'm not sure if it's range is 1/4 inch though, unless perhaps much more amplified. If tape heads were
available as surplus by some chance, or something similar, then perhaps an op amp could make a
significantlt consistent detection pulse.
Post Edited (VIRAND) : 10/28/2009 9:38:38 AM GMT