HWL Cell

[resonanceman]

I dried it using a convection oven, which is designed to cook food using hot air.
I set the oven at 300 deg. F. and ran it until most of the water was gone.
This formed a thin layer of crystal, then I left it to air dry the rest of the way.
I tried drying it completely but the crystal formed bubbles which I didn't want.
The crystal layer is about 1mm to 2mm thick.

I tried heating the crystals, not a good idea, the whole room smelled of Phosphorus,
and the crystal turned to a gummy mess thats hard to get off.
Heating to the curry temperature should be fine but don't try melting the stuff.

I'm still working on a better way to make cells out of this stuff.
I was thinking of getting some nice white quartz sand and using it for spacers between the plates.
Mix it up together in a little water and placing it between plates, then letting it dry.

My test cell is the SS plate with a 6cm x 4cm piece of Aluminum foil laying across the crystals.
I weighed the foil down with pennies, a simple test cell until I make some better cells.
Measurements:
Open circuit 800mV keeps creeping up had it up over 900mV.
    100k resistor 720mV.
      10k resistor 400mV kept steady over night
        1k resistor  75mV
       100 ohm resistor 32mV pressing on the pennies got it up to 40mV
After removing the 100 ohm resistor the cell jumped up to over 500mV.
And then continued climbing until it reached 800mV after about 5 minutes.

The main problem is the aluminum foil isn't keeping a good connection.
Some kind of conductive powder would be much better.

I'm still thinking up a better solution to this.
I'm considering coins covered with crystal stacked on each other to increase the voltage.

One point I want to make is I haven't applied any voltage to the cell to polarize it.
Doing so could get much better results, I just got the MAP a few days ago and am still learning about it.

Thanks for  explaining  a little more Harold

It  sounds interesting .......and    simple enough  for a non  chemist  to do .


Unfortunantly   I am between  jobs right now and I have about  100  things I want to try  for  every  dollar  I have available to try  them . 

Personaly  I think I would go for the  sticky mess   
batterys  are supposed to be messy arn't they?

A sticky mess between   2 dissimilar  metals ......apply  a voltage and let it cool  down  .......

It  almost has to work .       



gary   

[resonanceman]

If  the  sticky  cell worked ........  assuming  that   it gets liquid  enough ......what  about  potting  a  Stubblfield  earth battery in it ?

It  might be like a battery  within a battery


gary

[mdmiller]

for a spacer possibly you could use a piece of paper towel, TP, blotter paper, something porous.  use  a paper punch (or your 45 cal dirty harry) and perforate it, lay it on the foil.  then just pour the solution on it.  just a thought - Duane

[resonanceman]

for a spacer possibly you could use a piece of paper towel, TP, blotter paper, something porous.  use  a paper punch (or your 45 cal dirty harry) and perforate it, lay it on the foil.  then just pour the solution on it.  just a thought - Duane

Duane

I am assuming you are talking about  potting the  earth battery in Map

I was   thinking more on the lines of  taking a finiched  earth battery  and  finding a  container that it fits into nicely

Then  desolving some  Map in  water .........putting the whole thing in the oven ........and keeping the coil covered with  Map   until  enough water desolves so that the whole thing  starts to get solid .


If  it doesn't  work ..........THEN ........it is time to get  dirty harry


gary

[mdmiller]

for a spacer possibly you could use a piece of paper towel, TP, blotter paper, something porous.  use  a paper punch (or your 45 cal dirty harry) and perforate it, lay it on the foil.  then just pour the solution on it.  just a thought - Duane

Duane

I am assuming you are talking about  potting the  earth battery in Map

I was   thinking more on the lines of  taking a finiched  earth battery  and  finding a  container that it fits into nicely

Then  desolving some  Map in  water .........putting the whole thing in the oven ........and keeping the coil covered with  Map   until  enough water desolves so that the whole thing  starts to get solid .


If  it doesn't  work ..........THEN ........it is time to get  dirty harry


gary

I was referring to Harold's problem with maintaining foil spacing.  A piece of organic like absorbant paper would provide accurate spacing.  The earth battery is interesting.  That makes me think of the tesla bifilial.  Since MAP seems to have such a high dielectric, I'm curious what would happen if it was compounded like plates in a car battery.  For example, the layers would be (in cross section for assembly) as follows:

================      MAP saturated TP or whatever
=============O      foil with a copper electrode attached along the edge
=============        MAP saturated TP or whatever
=============         foil

The foil pieces might be say 2-3" wide and 12" long or longer, same with the MAP saturated spacer.  The MAP saturated spacer might want to be a little wider/longer to prevent any accidental foil shorts.  The foil with the electrode might be a little longer to start the wrap on the electode.

Roll it up in a spiral like a jelly roll, be sure the foil and attached electrode didn't touch the other foil.  Heat/dry to crystalize.  Measure the potential from the electrode to the outer foil.  Is there any accumulation of potential??  This might be a test relevant to other piezo materials.  - Duane