Over the weekend I got brave n took a aaa dry cell apart, undid the pos top of the cell, cut down one side of the cell, cut the bottom off, and unpeealed it. Removed the carbon rod, flattened the zink outer casing.

Put the carbon rod in the ground (cleaned it first), put the zink in the ground about 14" away from each other, and measured 1.2 volts.
Last 3 days it has been putting out 1.2 v DC, will be going back there on sunday so will recheck my setup then.
BTW, this setup is about 50Klm from where I live.

jim

I  have been thinking of  ways to make  what is in effect a real soft  spring  for the contacts .

my   best   idea for contact that is both  soft and  relatively  stable  I was thinking of  taking  a piece of  sheet metel  about  1/4 by 1/2   in
solder  your  contact lead  to  the  piece of sheet metal
fold  the  piece of sheet metal in half and  fold it flat "  clipping  " it to  a rubberband .

A piece of  wood or plastic  would have to be attached to the end of the  coil 
It would have to have a hole  for the core ...... through it ......and maybe 2 inches on  each   side of  the core .
the  rubber band  could be placed around this  piece of wood or plastic   so  that  the sheet metal contact was  flat on the  core bolt .   
I am thinking that   about 1  inch is needed on each side (of the  bolt)  for  free movement  up and down .     so  outside  of that one inch   you  could use shims   made of  plasitc    ,  thin cardboard or maybe  tooth picks    to space the   contacts  just  far enough away  to  break the contact .
the  rubber band  should not be  real tight ....


I hope that this makes sense .
It  was about  5 times harder to explain  than I expected


gary 
.

@ Gary
yeah, your idea could work OK, might have trouble with the wire soldered to the 1/2 X 1/4" armature, a solid cu wire will work, but it will fracture sooner than my suggestion here,  what do you think of this gary? use the loud speaker wire, the one which goes from the cone to the soldered contact, they are platted or wovern?

These are designed to withstand millions of flexture as the voice coil goes in and out of the speaker magnet.

jim

Quote from: electricme on May 06, 2008, 04:32:16 AM
@ Gary
yeah, your idea could work OK, might have trouble with the wire soldered to the 1/2 X 1/4" armature, a solid cu wire will work, but it will fracture sooner than my suggestion here,  what do you think of this gary? use the loud speaker wire, the one which goes from the cone to the soldered contact, they are platted or wovern?

These are designed to withstand millions of flexture as the voice coil goes in and out of the speaker magnet.

jim

Jim


your loudspeaker  wire sounds  good .

My idea for the  wire was to  have it a couple inches long  at  90 degees to the rubberband   ......it  would help keep the  contact  from swinging  both  side to  side and on its axis
I agree that the  wire will   eventually break      also the  rubber  band   will  decay  and  break

This is not  a  put it in the ground and  forget it for  years  idea .

This  is a  test to  prove it can work .     

then make a bigger   coil

once the coils  are large enough    we can switch to " standard "  components


gary

@Gary & Jim

Great suggestions.   I took a 4 inch wrapping paper cardboard roll and cut a section down to sizesay twelve inches tall, i then proceded to wind a single layer solonid style coil with the green radio shack magnet wire.  First i can use this as a modular secondary for testing, second i think the group should pull in some more material science knowledge so we can get a small design set to just give new folks to start with.  I really like .. i wanna say it was freezer or another gentelmen here who used the wood end caps like stubblefield did and a long bolt to secure them.   As jim mentioned before a small cordless skrewdriver or corded with a hex head in the chuck for the bolt would work well as a mini lathe for us to wind with.  Anyways i have two questions to throw out there, 1  i dint think ac was suspost to show up unless a load was present in a transformer sense.. that brings me to is my meter acting as a load in a dead short on the secondary winding.  Im thinking yes but i could be wrong.  it would act like a resistive load either way not an inductave one so the readings should hold true but should i put a resistor in line like a 1k ohm or somethign is wahts eating at me?
                                                                                                          Joe