Date: Wed, 6 Apr 2005 04:51:30 -0500
Reply-To: John Rodgers <inua@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@CHARTER.NET>
Subject: Re: DC party lights
In-Reply-To: <425165D7.3000006@mchsi.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Somewhere out there - a book, on the 'Net, somplace --- is a drawing - a
circle I think - that is a representation of the relation of all the
aspects of electricity.-- Volts, amps, Watts, Resistance, etc........the
old E=IR thing. I haven't found it but I know it exists. You can plug in
the numbers for just about anything and calculate for the unknown value
-- whether volts, amp, resistance, watts, whatever. There is also some
stuff about wire sizing for load.
Just thought I would bring it up!
Regards,
John Rodgers
88 GL Driver
Chelsea, AL
Al and Sue Brase wrote:
> BA:
> I'm no EE, but I did sleep at a....
> Watts is Volts x Amps. (at a power factor of 1.0, anyhow!)
> So, if a 120 watt string of lights takes 1 Amp at 120 Volts, and if you
> are lucky enough to find a similar string of lights made for 12 Volts,
> it would need 10 Amps to put out the same amount of light. At 10 Amps,
> those hair thin wires would be lighting up almost as much as the bulb
> filaments. They would need about #16 AWG wire to carry 10 amps.
> This is what the classical struggle between Edison and Tesla was all
> about. (when was that 1880's?)
> And it's called TRANSMISSION. And it IS somewhat related to that thing
> under your car. (in principle.) That's why those cross country power
> lines have 18 insulators holding each wire - they are 175,000 volts.
> Well, you CAN run stuff off your battery, but precious little
> without..... MONSTER CABLES! 18 year old boys know this! At least those
> that dream of 1000watt subwoofers.
> Don't they teach this stuff in school anymore? Like in 8th grade
> science class?
> Al Brase
>
> BA wrote:
>
>> On Sun, 03 Apr 2005 20:00:28 -0400, you wrote:
>>
>>
>>
>>> I'm looking to get a string of party lights to hand from my awning.
>>> I've seen some that have a DC plug on them but it really cuts down on
>>> the selection. Is it possible to just cut off the AC plug and splice on
>>> a cig lighter DC style plug?
>>>
>>> thanks
>>>
>>> JFF
>>>
>>>
>>
>>
>> Nope. There are power issues ... I don't entirely understand it but
>> that's because I got my EE degree (barely) many years ago, and I've
>> forgotten most of it (what I do for a living is software rather than
>> EE hardware).
>>
>> You can buy 12V strings of party lights, They're not cheap - not even
>> at WalMart. And as you've noticed, the selection is limited.
>>
>> If you google, you can find people who have converted AC strings of
>> lights to 12V DC. There's something about turning a serial string of
>> 120 V AC into parallel strings of 4 lamps each for 12V DC. That
>> "sounds" right to my vague EE memory ...
>>
>> My hero S saved me from having to re-learn enough to do it by
>> installing an inverter so I could run standard strings of party lights
>> from our aux battery. But as it happens, I just run the party lights
>> when we have an electrical hookup.
>>
>>
>> B(&S)
>> '87 Westy 'Esmerelda Blanc'
>> SoCal
>>
>>
>>
>
>
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