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John VanSickle wrote:
>> Damn... pitty we can't use heat to do *useful* stuff!
>
> Heat already does useful things. For instance, it causes cute girls to
> wear skimpy clothing.
Hey, neat!
(Pitty it's too damn hot to do anything about it...)
--
http://blog.orphi.me.uk/
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>> Oh... no, not really. I mean, sound vibrations are really, *really*
>> tiny. (Think about it; even when the sound is turned up painfully
>> loud, the speaker cones move by such a tiny amount you can't even see
>> them move at all!)
>
> Huh? Even at normal listening volumes I can see the bass cones move on
> mine... Try feeding a 20 Hz sine wave in and watch the cone... These
> are only perhaps 6" drivers, nothing spectacular. Mind you, I have
> never noticed the tiny 2" cones move on my PC speakers.
I have never seen any cone on any speaker move visibly - no matter how
much physical pain my ears were in. See, human ears are, like, *really*
sensitive...
> Huh? You are saying that they deliberately make speakers less efficient
> so that a higher voltage can be used to drive them? I've never heard
> that before.
Yes.
> Also I have never seen much "serious" hi-fi rated at
> anything like 200 W for home use. IME 15 W per channel is plenty to
> fill a medium sized room very loudly, perhaps if you live in a very
> large house and like listening to music very loud you'd want 200 W.
Hmm, I think my amplifier (nothing special) is rated at 60 W per
channel. (IIRC, into 8 ohms at 1 kHz.)
That's 60 W RMS by the way. Not like the "100 W" portable thing I once
owned that was actually 0.5 W RMS. ;-)
>> The mater claims 249.98 V.
>
> Sounds ok to me, the voltage will fluctuate a lot depending on lots of
> factors, like how much power people are using around you etc. Try
> measuring the voltage at different times of the day...
Wait... the *voltage* changes depending on how much you use it? That's
odd. I thought that potential difference was always constant, and it's
only *current* that changes...
>> Also, 49.97 Hz. (So much for "they keep it to exactly 50 Hz to help
>> all those clocks that use it". The frequency waivers all over the place!)
>
> And you think your meter is accurate to +/- 0.03 Hz?
Actually, the instruction book (which is oddly large for such a simple
device) states the accuracy for all readings. I forget what it says for
the frequency...
--
http://blog.orphi.me.uk/
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Mueen Nawaz wrote:
> I find it interesting that you're focusing on power rather than
> energy. How long do you spend boiling water vs how long is the washer
> running?
Well, that's the other part. The fridge doesn't use much power, but it's
permanently switched on. (Altough obviously it only draws any current
now and then.) So far it's clocked up a fair number of kWh...
--
http://blog.orphi.me.uk/
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Orchid XP v3 wrote:
>>> I just find it bizzare that this huge washing machine, spinning away
>>> to violently that it's deafening to stand near and you'd probably be
>>> injured if you touched it, uses about 5% of the power of a teeny
>>> little kettle. Far out!
>>
>> And then you'd probably also be surprised how loud your speakers are
>> when you feed just 5 W into them.
>
> Oh... no, not really. I mean, sound vibrations are really, *really*
> tiny. (Think about it; even when the sound is turned up painfully loud,
> the speaker cones move by such a tiny amount you can't even see them
> move at all!)
>
have you taken into account that the overlap in frequency resolution of
your ears and eyes is very small? You can not hear anything below 20 Hz
or see anything above 50 Hz.
> AFAIK, the reason we have 200 W amplifiers and speakers isn't so much
> because it takes that much electricity to move air around, but to reduce
> RF pickup in the speaker wire... (Or rather, to reduce the
> *signifigance* of such pickup.)
>
>>> PS. 230 V? I thought it was 250 V...
>>
>> IIRC the spec was changed from 240 +/- 10% to 230 +15% -5% (or
>> something equally stupid) to get us inline with Europe.
At the same time the *rest* of Europe changed from 220 to exactly the
same specification. FYI the UK is *within* Europe.
>> Doesn't your meter tell you the voltage too?
>
> The mater claims 249.98 V.
>
> Also, 49.97 Hz. (So much for "they keep it to exactly 50 Hz to help all
> those clocks that use it". The frequency waivers all over the place!)
>
RTFM The instantaneous frequency (how is that for an oxymoron) may vary,
but there will be exactly 432000 cycles in a day.
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andrel wrote:
>> Oh... no, not really. I mean, sound vibrations are really, *really*
>> tiny. (Think about it; even when the sound is turned up painfully
>> loud, the speaker cones move by such a tiny amount you can't even see
>> them move at all!)
>>
> have you taken into account that the overlap in frequency resolution of
> your ears and eyes is very small? You can not hear anything below 20 Hz
> or see anything above 50 Hz.
And when I start up the engine of my car, the various parts move far too
fast for the eye to follow. But you *can* see the blur of moving
objects, and there is little doubt that they're moving. ;-)
>> Also, 49.97 Hz. (So much for "they keep it to exactly 50 Hz to help
>> all those clocks that use it". The frequency waivers all over the place!)
>>
> RTFM The instantaneous frequency (how is that for an oxymoron) may vary,
> but there will be exactly 432000 cycles in a day.
Behold: Differential calculus. ;-)
--
http://blog.orphi.me.uk/
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Orchid XP v3 wrote:
> Gee, I wonder what our lawn mower uses...
Mine has a nifty engine that breaks down all sorts of bio matter into
simple carbohydrates and then burns them. It's flexible enough to work
on matter as diverse as fruits, grains, and meats, although certain
spices have been known to give it trouble. Also, you need a fair amount
of fiber mixed in, otherwise the whole thing can get clogged.
--
...Ben Chambers
www.pacificwebguy.com
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Orchid XP v3 wrote:
> andrel wrote:
>
>>> Oh... no, not really. I mean, sound vibrations are really, *really*
>>> tiny. (Think about it; even when the sound is turned up painfully
>>> loud, the speaker cones move by such a tiny amount you can't even see
>>> them move at all!)
>>>
>> have you taken into account that the overlap in frequency resolution
>> of your ears and eyes is very small? You can not hear anything below
>> 20 Hz
>> or see anything above 50 Hz.
>
> And when I start up the engine of my car, the various parts move far too
> fast for the eye to follow. But you *can* see the blur of moving
> objects, and there is little doubt that they're moving. ;-)
Why do you think that those frequencies are far above 50 Hz?
What sound does your motor make? Can you find the base frequency on your
keyboard?
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"Orchid XP v3" <voi### [at] dev null> wrote in message
news:46dc4c7a$1@news.povray.org...
> John VanSickle wrote:
>
> >> Damn... pitty we can't use heat to do *useful* stuff!
> >
> > Heat already does useful things. For instance, it causes cute girls to
> > wear skimpy clothing.
>
> Hey, neat!
>
> (Pitty it's too damn hot to do anything about it...)
>
Two words...
Swimming pool
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On Mon, 03 Sep 2007 10:31:33 +0200, scott wrote:
>>> How about running an LCD panel, transmitting and receiving data from a
>>> base-station 10s of miles away, interpreting incoming data packets,
>>> waiting for key presses? All for 10 mW.
>>
>> Well, the distance to the base station doesn't matter unless it's
>> wireless, then it's just the transmitter power.
>
> I was just illustrating that a normal mobile phone can do all that stuff
> (both transmitting and receiving to the base station) for around 10 mW.
I *think* the xmit power of a cell phone is a bit more than that...But
I'd have to check.
Jim
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Jim Henderson wrote:
> I *think* the xmit power of a cell phone is a bit more than that...But
> I'd have to check.
Depends on the phone system. CDMA was originally designed to be an
undetectable transmitter for military use. IIRC, its power ranges
between 2.5mW and 5mw.
--
Darren New / San Diego, CA, USA (PST)
Remember the good old days, when we
used to complain about cryptography
being export-restricted?
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