From: carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick)
Newsgroups: sci.energy
Subject: Re: Why not 120 VDC ?  Why invert?
Date: 26 Jan 1993 11:01:45 GMT
Organization: HST Wide Field/Planetary Camera
Reply-To: carl@SOL1.GPS.CALTECH.EDU
NNTP-Posting-Host: sol1.gps.caltech.edu

In article <1993Jan25.205334.4078@michael.apple.com>, ems@michael.apple.com (E. Michael Smith) writes:
>Two things:  1)  I'm allergic to wool.  (We use a fluffy comforter) and

That's OK.  There are synthetics that are even better than wool for blankets.

>2)  My wife uses a heating pad for lower back pain.

That's not the same as an electric blanket.  I pointed out one use for devices
of this sort (electric blankets used in treating hypothermia).  Heating pads
are another.  They're both relatively uncommon uses (though the medical uses of
heating pads are much more common than those of electric blankets). 

>I suppose I could
>have taken the time to clarify this, but wanted to avoid the wasted
>bytes.  But since the point was pressed, I'll waste em...  There is
>no way I'm going to get my wife off of her heating pad. (Endo...). 
>There a other folks who use electric blankets similarly...

Could you point out to me such a use of a full-sized electric blanket?


>I've slept under a ton of blankets in cabins in the mountains in
>winter.  It was OK, but I can sympathise with folks who live in
>places that are very cold and want an electric blanket.

There are synthetic blankets that are quite effective.  And as I've pointed
out, there are blankets using aluminum cores that are even more effective.  In
fact, you can buy something similar (I think it uses aluminized mylar) in most
any place that sells camping supplies.  One term I've heard for the things is
"space blankets."

>I HAVE
>found them personally useful for pre-warming the bed, then turn
>them off when I get in.  (Headonism known no bounds! ;-)

Gee.  Back when I was a kid, there was something called a hot-water bottle.


>>So you're going to run TWO sets of wires throughout your home, one for AC and
>>one for DC?  Once you've committed to the expense of having an inverter in the
>>first place, the cost of increasing the capacity of the unit under
>>consideration is relatively small.
>
>That was the plan.  And, as I also pointed out in the post you are
>responding to (but which lines you have deleted), on reflection I 
>thought that the complication of dual wiring was probably why it
>wasn't done.  

OK.  I may have come into this thread a bit late.  I don't remember seeing that
in the post to which I originally replied.

>BTW, the cost increases may or may not be 'relatively small'...
>I ALREADY have dual wiring in my house.  Part 120 VAC, part 220 VAC.
>The cost of adding a small part of 12 VDC is trivial.  (One battery
>at about $100 and a panel mounted next to the main panel into
>which the re-directed wires could be moved.  Call it $150 total DIY.)

Sorry.  I haven't done any household wiring since the days when all you had to
do was put a metal plate on the studs where you ran the wires through them.  If
you've got conduit, the cost of stringing another set of wires isn't all that
high.
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL

Disclaimer:  Hey, I understand VAXen and VMS.  That's what I get paid for.  My
understanding of astronomy is purely at the amateur level (or below).  So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it.  If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.
Xref: sparky sci.energy:7223 talk.environment:5728