Date: Fri, 21 Sep 2001 18:55:38 -0600
Reply-To: Rachel Cogent <Gnarlodious@EARTHLINK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rachel Cogent <Gnarlodious@EARTHLINK.NET>
Subject: Dissertation on electric blankets.
In-Reply-To: <B7D0D571.1358%mwmiller@cwnet.com>
Content-type: text/plain; charset="US-ASCII"
You would need an inverter because electric blankets normally run on 120
volts AC and your Westy is 12 volts DC. The resistance wire in the blanket
and all resistance circuits are set according to voltage. In other words you
COULD run your electric blanket on 12 VDC IF you made the length of the wire
1/10th of the 120 V length, in fact the blanket would run on 12 VDC except
it would produce 1/10th the heat, which is not enough to keep you warm. Or
you could wire 10 12 Volt batteries in series and get 120VDC, this is an
impractical solution. Nobody wants 10 batteries in their Westy, and besides,
how would you charge them?
The most practical solution would be to acquire a 12 V blanket, which we
have been discussing, there are two extra advantages to this solution:
1: You save the 20% waste needed by the inverter to convert the power, which
ends up as heat anyway, but not where you want it.
2: DC power does not radiate electromagnetic waves, but AC does because it
is changing direction 120 times per second.. This is the big brouhaha with
cellphones and power lines which allegedly cause cancer. Having an AC
electric blanket on your body all night is supposedly not good.
In fact the CPA should mandate all electric blankets be sold must run on 120
VDC, but the technical problems are huge and would add about 50$(at least)
to the cost of an electric blanket. Since I have a 12V power supply in my
Vanagon anyway it is not a problem.
The End
Entity mike miller spoke thus:
> Second. Why would you need an inverter for an electric blanket?
>
> Mike
>
>> From: Rachel Cogent <Gnarlodious@EARTHLINK.NET>
>> Reply-To: Rachel Cogent <Gnarlodious@EARTHLINK.NET>
>> Date: Fri, 21 Sep 2001 10:41:10 -0600
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Re: Seeking warmth in my Westy
>>
>> Well let's see.
>> If an electric blanket uses 180 watts and you sleep 8 hours that is 1440
>> watts. Assuming a 75% duty cycle if it is very cold but you have other
>> blankets over the heater that is 1080 watts. The average inverter is 80%
>> efficient so that brings it up to 1296, lets say the original 1440 to be
>> liberal. That is 1440 watthours. If 1440 / 12 volts =120 amp hours is true,
>> and I think it is then the average battery should do it.
>> Actually having a 12 volt electric blanket would be very cool....er, warm I
>> mean. An added bonus is that you don't have the AC next to your bod with the
>> DC thereby preventing cancer.(if you believe the fearmongers)
http://www.preparedness.net/12volelblan.html
>> Entity Royston, Jerry spoke thus:
>>
>>> I was thinking about getting an electric blanket to accomplish this. Of
>>> course you would need an electrical hookup. Has anyone else used electric
>>> blankets in their Westy? How long would it take to run a battery down with
>>> one on all night?
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