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chaosdrone
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Posts posted by chaosdrone
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need something with a resolution higher than 12 bits and a sampling rate around 1-10 MHz for the cheapest possible price ???
any suggestions would be appreciated! -
I answer this ::)
well the pristine PANI should exhibit a conductivity in the magnitude around 10^8 .. well but that's not all .. i'll further need to optimize the suspended phase volume fraction and the physical dimensions of the composite block in order to optimize the current magnitude.. .. I am intending to start calculating that briefly. :-X -
yeah five volts from a switching PS would do, across a highly resistive assembly ;) , i need to choose some accurate op-amp model though :-\
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;D lol
well, someone advised me with measuring the shot-noise phenomenon, by the use of a current integrator.
and this idea is so appealing to me, sounds like it takes down the measurement process to the edge.
have found much circuit schematics for this though, yet i wonder which particular design should i adopt, for a simple precision current integrator? ::) -
:-[ yeah but even the low accuracy synthesis of a preliminary goo would require a specialized polymers lab, you know .. goo can't be prepared anywhere but in goo-labs :(
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who would hate a test for free anyway ;)
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:D well i first got to theorize the whole thing from synthesis to advanced testing before i get granted access to the lab inwhich i'll be able to make that goo :-[
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i was just reading this .. http://pdfserv.maxim-ic.com/en/an/AN2236.pdf
sounding like if i succeeded in turning my very minuscule current into voltage then i'd be able to simulate that PIN diode in the circuit .. and hence gain such precision .. right?
but how :D ?? -
Well ,,apart from any quantum or coupling efficiency .... what if we assumed to have an ejected photo-electron inside a polymer ... what circuit should be most efficacious in sensing such freed electrons and what would be the minimal sensitivity of the detection (the least number of ejected electrons that could be detected)??
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yeah i have been reading relentlessly lately about practical evaluation of such theories like EMT, percolation, maxwell, pal model, etc... and all what i have found was an unbelievable lack in generality for such laws being very case-dependant with paradoxical behaviours for many composite cases :o
beside the crystals should induce photoemission already in the polymer phase which puts in quite of a predicable situation having to develop my unique theoretical interpretation to whatever (supposedly very accurate) data i get. :-[ -
that'd not be very accurate ???
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yeah, decimal points
have looked up for precision resistivity measuring devices and they provide no more than 4.5 digits display with 0.03% error, which is not good and not as portable as i wish they are very bulky indeed :'(
the polymer's conductivity ranges from 10^-8 to 10^-11 , depends on the synthesis method ... so my values should be around that.
never mind about the avalanche effect as i have just read a paper describing the breakdown voltage of the polymer and it turned to be so high for practical thicknesses. -
yeah ..now you understand me ;) .... I am after making a circuit that could measure the value of photoemission or any related value to it with 7-8 digits of precision like conductivity, avalanche effect, etc.
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Apparently you have misunderstood me :(
first concerning the uniform electric field .. well thats partially right .. i need to have conductors at each end of the polymer so i can somehow measure the conductivity of the composite/polymer... so yes i'll someway or another need to implement an electric field this way.
Yet, this has got nothing to do with electrophoresis, the crystals should bear no local charge and hence they won't move in an electric field.
only the "freed electrons" though of the conducting polymer would be able to move .. and what i want to measure is how much more freed electrons got liberated by the effect of irradiation.
Besides, the crystals should not ionize as they'd not be in a soluble or in a condition favouring their ionization .. neither should i be in need for high voltages i bet .. :-\ -
:-[ oh .. great in that case well:
1- I can't deduce what do you particularly mean by a probe, but i should be wet moulding the polymer beads with the composite crystals in the shape i desire or in a membrane template with the desired thickness afterwards i should have some form of conductive plates across it (but i haven't managed the details of that yet as it should be easy).
2- I should essentially be comparing between the blank and composite polymer blocks, quantitative measurements could be made afterwards to say the blank and that'd be factored by the relative values i get.
3- the source of light should be the embedded crystals themselves, they should be emitting 2 major frequency peaks one is a fraction of an eV higher than the band gap of the polymer and the other is 1.x eV aswell higher aswell.
4. i can have access to a vacuum oven in that lab for sure but can't guarantee you high powers of available vacuum pumps .. not more than a couple HP's i think.
now.. what should I do? :-X -
In what sense do you want to access the polymer?
;D to assess is to estimate, characterize or evaluate a particular property -
I was wondering what would be the most simplistic approach, i have a particular polymer composite (based on emeraldine base) and this composite should exhibit some weak photoemissive property that i wish to assess. ???
some have advised me with with an ADC that should give me up to 8 significant figures of voltage value across the polymer.
others have advised a log amp that should probe directly the interesting fraction of the value.
also an avalanche current detection assembly across the polymer was advised.
i do not really know what to do .. and even if picked one of those i would be in need for its corresponding schematic ::)
any help would be appreciated,
and thanks. -
i wished to make a simple electrical heater that heats a liquid pool .. (around 1 litre) at constant temperatures .. i just wished to have a clue about the details of the feedback circuit and how the overall circuit should look like ..
::)
so if anyone do have a schematic for such a projects would please share it .. thanks :-*
looking for a USB Digital Acquisition module
in Sell/Buy electronics - Job offer/requests
Posted
thank you alex for your post :-* ... i have stumbled across this piece before:
http://sine.ni.com/nips/cds/view/p/lang/en/nid/14604
its price is acceptable, yet do you have an idea about for how much is the LabView soft :o ($800+)
also on mc a piece like this http://www.mccdaq.com/usb-data-acquisition/USB-1208FS%20.aspx should require at the very least TracerDAQ Pro which is even more expensive than the hardware itself :(