asciilifeform: ( but no, at least over here we dun have 'enterprising'. we have repair crews that barely repair )
asciilifeform: not mined by usg, lol. by copper hunters..
asciilifeform: ( i can picture a near future when hv line rights of way are mined, say )
asciilifeform: the spread of copper bandits might change the equation tho.
asciilifeform: in some places they guard'em, but usually not (picture the cost), typically proprietor figures that monkeying near hv lines is self-punishing
asciilifeform: just stand in the near field. ( recall the folx with unplugged fluorescent lamps )
asciilifeform: for these, frying pan wound with magnet wire ~at ground level~, as tuned circuit, is actually enuff
asciilifeform: btw peltier, solar, piezo are not the only possib harvests. there is also inductive coupling from mains cabling ( street lights, etc , user yer imagination )
asciilifeform: ( don't put logger in the box per se, will miss good % of the flips, as e.g. sd card eats ridiculous current , which the harvester may or may not at a given time be able to supply )
asciilifeform: from the intervals, can compute energy in.
asciilifeform: wire it up to a (battery-powered) universal remote thing, with the rx end indoors , where you can log.
asciilifeform: think of the harvester as an impedance matcher between the physical source of energy, and the consuming device.
asciilifeform: ltc3108 has an intake transformer . the demo board is sold in two variants, one where it has a low:high winding ( for peltiers, solar ) and one where high:low ( for piezos ). the latter is for noise/vibratory harvester -- e.g. tree branch in the wind.
asciilifeform: from this, in turn, can say, e.g., 'in the daytime, september, such-and-such latitude, can get J joules/sec , then after sundown, J', ... ' etc
asciilifeform: from this, can calculate practical energy availability.
asciilifeform: how to do : it charges cap ( the demo unit i have here from china, has 4 1F 2.2v caps ) and runs a boost converter from these, as well as lighting up 'power good' pin when 3.3v (from the latter) is available. so you put a test load on the 3.3v out ( say , 1W 100 ohm resistor ) and record events when 'power good' signal changes.
asciilifeform: mircea_popescu: want to record not simply voltage, but just how many milliwatts/hrs available from the harvester ( in field practice you cannot do much of anything with e.g. peltier without harvester )