Date: Fri, 31 Aug 2007 19:21:03 -0700
Reply-To: neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil N <musomuso@GMAIL.COM>
Subject: Re: Was: Mp3/FM + mono....reccomends? NOW: how much does your CD
unit draw??
In-Reply-To: <46D8C952.80006@gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
cool. I found an ohms law calculator (yes I'm that lazy) online.
I started to get to know that stuff when younger, but I understand
what you're saying.
It may be that my Kenwood isn't that much less efficient than the Sony
though the only way to truly know, is to measure how much they each
draw when set to the same volume output...... I think.
Neil.
On 8/31/07, Michael Elliott <camping.elliott@gmail.com> wrote:
> Power and volts are related to each other that easily. The rated voltage is how many volts
> the amplifier needs to operate, and let's just say it's 12 volts -- battery volts.
>
> Power is volts x amps. If the amplifier is sending (say) 20 watts into the speaker it
> needs to get the power from someplace. Stick to watts. If your amplifier is receiving 12
> volts from the battery, then in order to deliver 20 watts into the speaker it needs to get
> at least 20 watts from the battery. With a 12 volt battery, the current needed is 20/12 =
> 1.7 amps.* Actually more because the amplifier is not 100% efficient.
> "Rated Power" refers to how many watts the amplifier can put into standard speaker loads
> without exceeding a standard amount of distortion. Believe me, you don't want to get into
> all this unless you really want to study audio electronics.
>
> * See Ohm's Law.
>
> --
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> KG6RCR
>
>
>
> neil N typed:
> > I think I understand. But....
> >
> > Even though they use the term "rated power" in the same category as
> > Amps/operating voltage used by unit, "rated power" refers to the
> > actual audio output in watts and how it impacts how many amps drawn?
> >
> > "Rated power" does NOT mean "operating voltage" ?
> >
> > :^)
> >
> > Sorry for such elementary questions. I just found it hard to beleive
> > that a newer unit would be that much more energy efficient only
> > drawing 45 Watts.
> >
> > (though exactly how Sony got that figure. i.e. how loud stereo
> > playing, is CD motor spinning, I don't know. Kinda like fuel mileage
> > figures.... YaBaDaYabba.....)
> >
> > Neil.
> >
> >
> > On 8/31/07, Michael Elliott <camping.elliott@gmail.com> wrote:
> >> The phrase "rated power" refers to however watts the manufacturer claims the unit can
> >> deliver into some speaker load. I think the KDC-S3007 is rated at 4 x 30 watts, which is
> >> 120 watts into all four speakers combined. During that 120 watt exercise the power has to
> >> come from someplace. Like your battery. That's where the 10 amp current draw comes in.
> >>
> >> If you're not playing any music, then the current draw will be quite a bit less. How much?
> >> Depends on the design of the product.
> >>
> >> How much current does your Kenwood draw when you're playing the music you like at the
> >> volume levels you like? Somewhere between 10 amps and the no-signal condition. It might
> >> not be much more than the no-signal current draw, depending on how loud your music is.
> >> Mellow Yellow's stereo draws about 1.25 amps when it's playing no music or just soft
> >> music. If you're a head-banger and are clipping the shit out of your amp then you could be
> >> drawing 10 amps, sure, and you're asking to be evicted from any campground I camp at. But
> >> if you, like me, listen to soft music -- maybe a little Coltrane or Baker, maybe a bit of
> >> Vivaldi or Puccini, whatever -- then you only need to worry about the amp's no-signal
> >> current draw.
> >>
> >> --
> >> Mike "Rocket J Squirrel" Elliott
> >> 71 Type 2: the Wonderbus
> >> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> >> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> >> KG6RCR
> >>
> >>
> >>
> >> neil N typed:
> >>> Ok. So it seems that my in dash CD/FM unit is a "Kenwood" not a Panasonic.
> >>>
> >>> A search on the net' tells me the KDC-S3007 is 1996 technology. Hmmmm.......
> >>>
> >>> Like, duh.
> >>>
> >>> So I RTFM, and it say's:
> >>>
> >>> Operating voltage ........... 14.4 V (11-16 V allowable)
> >>>
> >>> Current consumption ...... 10.0 A at Rated Power.
> >>>
> >>> Via this page:
> >>>
> >>> http://www.angelfire.com/pa/baconbacon/page2.html
> >>>
> >>> it seems my stereo draws a staggering 144 Watts. Can this be??
> >>>
> >>> Another, ahem, more modern stereo, the Sony CDX-GT310 (kindly
> >>> reccomended to me via pmail), draws 45 Watts.
> >>>
> >>> This could explain, in part, the big drain on my house battery.
> >>>
> >>> Like duh...... --- ;^)
> >>>
> >>> Just in case anyone else was having this problem!
> >>>
> >>> Neil.
> >>>
> >>>
> >>> --
> >>> Neil Nicholson. 1981 Air Cooled Westfalia -
> >>> "Jaco" (Bustorius)
> >>>
> >>> http://web.mac.com/tubaneil
> >>>
> >>> Please send me your Vanagon/Westfalia links!
> >>> http://vanagonlinks.googlepages.com/home
> >>>
> >
> >
>
--
Neil Nicholson. 1981 Air Cooled Westfalia -
"Jaco" (Bustorius)
http://web.mac.com/tubaneil
Please send me your Vanagon/Westfalia links!
http://vanagonlinks.googlepages.com/home
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