[MR] Atlantia Digest, Vol 65, Issue 39 (Do These Things Actually Work)

[Roy B. Scherer]

At 02:11 PM 6/12/2008 -0700, CHRISTOPHER wrote:
>Anyone ever try dry ice in them? That should help a lot with the 
>humidity off the ice. Afterall, using ice would make it a cold humidifier.

         Pardon the obvious pun, but that's a really "cool" idea.

>If you have any electrical ability (or a friend who does) you can 
>hook up batteries ina sequence of 3's. I can't give you any idea 
>how, but when i drove truck, my truck's fridge could run for 2 or 3 
>days with the engine off.

         This is an easy thing to learn . . . but has proven to be 
most involved to set forth onscreen.  I'll give the bare essentials 
here, but allow me to suggest that you visit 
<http://electronics.howstuffworks.com/battery.htm> and 
<http://electronics.howstuffworks.com/battery3.htm> for more information.

1) There are three ways to hook up electrical stuff: "series", 
"parallel", and of course our old friend "series-parallel".  These 
are pretty obvious.  If an electrical gadget is represented as:
{x} and wires are represented as either | or --,
then three gadgets hooked up in series look like:
(in)--{x}--{x}--{x}--(out)
while the same three can be hooked up in parallel as:
|----{x}----|
|----{x}----|
|----{x}----|
|            |
(in)     (out)

2) To run a 12-volt fan, you put it in series with a battery.  It 
looks like this:
|----{FAN}--------{+BATTERY-}-----|
|---------------------------------------------|
         This arrangement will run the fan until the battery runs down.

3) To keep the battery from discharging (running flat) too soon, use 
one or more additional batteries connected in parallel, like this:
|----{FAN}--------|-{+BATTERY-}-----|
|                    |-{+BATTERY-}-----|
|                    |-{+BATTERY-}-----|
|-----------------------------------------------|
         That is, hook up the positive terminals of two or more 
batteries to each other, and the negative terminals of those 
batteries to each other.  Then hook up the fan between the combined 
positive and the combined negative terminals.
         This arrangement (assuming that all three batteries are 
identical) will run the fan for three times as long as the simple 
hookup shown in (2).

4) To connect the batteries and the fan, you need to use copper or 
aluminum wires with connectors on each end.  Plain old jumper cables 
will do, but they're actually overkill to power a simple fan.  Go to 
Radio Shack (or some similar source) and buy a pack of test leads in 
the heaviest wire size available.  /RANT ON The idiots do not show 
the thicknesses of the wires used in these items on their 
websites!  You'll need to physically visit the store and 
check.  Thicker wire=better for this purpose. /RANT OFF  The Radio 
Shack website shows three possibilities:
<http://www.radioshack.com/product/index.jsp?productId=2062661&cp=&sr=1&origkw=jumper+cables&kw=jumper+cables&parentPage=search>24" 
(60.9cm) Insulated Test/Jumper Leads
Model: 278-1157  |  Catalog #: 278-1157 $7.69 for eight.
<http://www.radioshack.com/product/index.jsp?productId=2062622&cp=&sr=1&origkw=jumper+cables&kw=jumper+cables&parentPage=search>30" 
(76.2cm) Test/Jumper Leads
Model: 278-001  |  Catalog #: 278-001 $6.99 for four.
<http://www.radioshack.com/product/index.jsp?productId=2062660&cp=&sr=1&origkw=jumper+cables&kw=jumper+cables&parentPage=search>14" 
(35.3cm) Insulated Test/Jumper Leads
Model: 278-1156  |  Catalog #: 278-1156 $7.69 for ten.

Lastly, I advise you to wear gloves and eye protection while hooking 
up and unhooking the batteries and fan.  A lead-acid battery (auto or 
marine battery) releases hydrogen gas, which is a flammable substance 
and can react explosively.  Connecting and disconnecting components 
will generally create a spark, which may ignite a hydrogen-air 
mixture in an explosive manner, which may injure or kill you or 
others.  Once you have made a hookup, observe the apparatus for 
several minutes.  If any of the wires or other components are 
smoking, or melting, disconnect power immediately.  Feel the ends and 
the middles of each jumper; if any part feels warm or hot, then 
immediaely disconnect the power.  If malign entities from the nether 
regions appear and demand the souls of any persons, disconnect the 
power immediately and consult a qualified specialist.  Information 
provided "as is", and is acted upon entirely at your own risk.   Your 
mileage may vary.  Offer void where prohibited.
-- YIS,
-- Britton


end

                 - - Roy B. Scherer
  [8 N. Sheppard Street, Richmond, VA 23221; (804) 355-7612]
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         "Against stupidity,
         the gods themselves struggle in vain.
         -- Friedrich von Schiller (1759 - 1805)
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