I just found that some circular have logic-defying efficiency.
For example, dewalt DW368K specification says 15 Amps motor, and the max
output is 2200 Watt. However, the input power is 15 Amps x 120V = 1800 Watt.
How could it consume 1800W of electricity and produce 2200W of power? It
must have an effiiciency exceeding 100%!
Another example: Milwaukee 6391 has a 15 Amp motor and claim the saw has 3
1/4 horsepower.
Since 1 horsepower = 746 W, 3.25 HP = 2424.5 Watt. It is even more efficient
than the dewalt!!
Why hasn't these more than 100% efficient machines made the headlines?
"Lawrence Wasserman" <[email protected]> wrote in message news:[email protected]...
> In article <9%[email protected]>,
> peter <[email protected]> wrote:
> >I just found that some circular have logic-defying efficiency.
> >
> >For example, dewalt DW368K specification says 15 Amps motor, and the max
> >output is 2200 Watt. However, the input power is 15 Amps x 120V = 1800 Watt.
> >How could it consume 1800W of electricity and produce 2200W of power? It
> >must have an effiiciency exceeding 100%!
> >
> >Another example: Milwaukee 6391 has a 15 Amp motor and claim the saw has 3
> >1/4 horsepower.
> >Since 1 horsepower = 746 W, 3.25 HP = 2424.5 Watt. It is even more efficient
> >than the dewalt!!
> >
> >Why hasn't these more than 100% efficient machines made the headlines?
> >
> >
>
> Ho hum, those 3 hp saws and routers have all been pushed to the back
> pages by the 5 and 6HP shop vacuums.
>
...and 6 hp air compressors rated at 15A, 120v input.
>
> --
>
> Larry Wasserman Baltimore, Maryland
> [email protected]
>
"peter" <[email protected]> wrote in message news:<9%[email protected]>...
> How could it consume 1800W of electricity and produce 2200W of power?
The extra 400W is pumped in via a hyperspace wormhole direct from the
marketing division.
Maybe this explains Hawking radiation and where all that extra energy
goes ?
Ho Lee Fuk powertools are powered by black holes !
On Thu, 22 Jul 2004 13:08:21 GMT, peter <[email protected]> wrote:
> I just found that some circular have logic-defying efficiency.
>
> For example, dewalt DW368K specification says 15 Amps motor, and the max
> output is 2200 Watt.
"max", or "peak"? The peak of a 120V sine wave is 177 volts, it's only at
that at the top of the graph, but it is the peak. It's a meaningless thing
to use for anything other than marketing, because the RMS is what matters.
Marketing weenies, of course, aren't into engineering truths.
I would suspect that they're equating "peak" with "max" now, for the same
reason.
> Why hasn't these more than 100% efficient machines made the headlines?
heh...
Black (magic) and Decker
"GigaNews" <[email protected]> wrote in message
news:[email protected]...
> Seriously, I have always wondered about this. Someone once told me this
was
> a 'peak' horsepower.
>
> I must admit that although I did well in my EE classes, that was years ago
> and even then I always viewed electricity as being something close to
black
> magic and voodoo.
>
> Does anybody have an explanation of how they get away with this?
>
>
Regarding your comparison of electric and gasoline horsepowers. Keep in mind
there are more than one method of creating horsepower rating for gas engines
(and possibly electric). I can remember the days when the Province of
Ontario required the horsepower rating of engines on car ownerships. People
would get upset when they compared the licence horsepower with the brochure
horsepower. The license would use "brake-horsepower" the brochure would use
another system. For example the VW bug was rated 26 hp on the license while
the showroom would claim, something like 60 hp for the engine.
"U-CDK_CHARLES\Charles" <"Charles Krug"@cdksystems.com> wrote in message
news:IkSLc.11$V9.9@trndny04...
> On Thu, 22 Jul 2004 11:47:30 -0400, J. Clarke <[email protected]>
wrote:
> > GigaNews wrote:
> >
> >> Seriously, I have always wondered about this. Someone once told me this
> >> was a 'peak' horsepower.
> >>
> >> I must admit that although I did well in my EE classes, that was years
ago
> >> and even then I always viewed electricity as being something close to
> >> black magic and voodoo.
> >>
> >> Does anybody have an explanation of how they get away with this?
> >
> > No or poorly defined standards. Different ratings for different
purposes.
> > "Amps" for how big a circuit it needs. "Watts" for marketing.
> > "Horsepower" the same.
> >
>
> "Industry Practice" with universal motor-powered devices is to quote the
> instantaneous peak before self destruction iirc, if it's regarded as
> relevant, as in power tools. Nameplate amps is a better indication of
> "motor power" than "quoted HP"
>
> "Sears Practice" with Induction Powered devices is to use words like
> "1-1/2 HP Induction Motor develops 3HP maximum" which is, iirc, based on
> locked-rotor current draw. You wanna hit that with an oak not, but not
> too often. Again, compare nameplates or just read carefully.
>
> Vacuum manufacturers typically quote "Peak vacuum HP" which is PURE
> drivel as far as I'm concerned.
>
> Aircompressors have similar meaningless numbers.
>
> Another hitch is that electric motors will HAPPILY supply "peak HP" for
> short periods. Wheras gasoline engines simply cannot. So a 5HP Unisaw
> electric would need a 10HP gas or diesel engine to operate it.
>
> Compare air compressors with similar pressure and CFM ratings, gas vs
> electric and you'll quickly see what I mean.
>
>
>
On Thu, 22 Jul 2004 10:30:03 -0400, "GigaNews" <[email protected]>
wrote:
>Seriously, I have always wondered about this. Someone once told me this was
>a 'peak' horsepower.
>
>I must admit that although I did well in my EE classes, that was years ago
>and even then I always viewed electricity as being something close to black
>magic and voodoo.
>
>Does anybody have an explanation of how they get away with this?
>
they just lie....
Seriously, I have always wondered about this. Someone once told me this was
a 'peak' horsepower.
I must admit that although I did well in my EE classes, that was years ago
and even then I always viewed electricity as being something close to black
magic and voodoo.
Does anybody have an explanation of how they get away with this?
On Thu, 22 Jul 2004 11:47:30 -0400, J. Clarke <[email protected]> wrote:
> GigaNews wrote:
>
>> Seriously, I have always wondered about this. Someone once told me this
>> was a 'peak' horsepower.
>>
>> I must admit that although I did well in my EE classes, that was years ago
>> and even then I always viewed electricity as being something close to
>> black magic and voodoo.
>>
>> Does anybody have an explanation of how they get away with this?
>
> No or poorly defined standards. Different ratings for different purposes.
> "Amps" for how big a circuit it needs. "Watts" for marketing.
> "Horsepower" the same.
>
"Industry Practice" with universal motor-powered devices is to quote the
instantaneous peak before self destruction iirc, if it's regarded as
relevant, as in power tools. Nameplate amps is a better indication of
"motor power" than "quoted HP"
"Sears Practice" with Induction Powered devices is to use words like
"1-1/2 HP Induction Motor develops 3HP maximum" which is, iirc, based on
locked-rotor current draw. You wanna hit that with an oak not, but not
too often. Again, compare nameplates or just read carefully.
Vacuum manufacturers typically quote "Peak vacuum HP" which is PURE
drivel as far as I'm concerned.
Aircompressors have similar meaningless numbers.
Another hitch is that electric motors will HAPPILY supply "peak HP" for
short periods. Wheras gasoline engines simply cannot. So a 5HP Unisaw
electric would need a 10HP gas or diesel engine to operate it.
Compare air compressors with similar pressure and CFM ratings, gas vs
electric and you'll quickly see what I mean.
"peter" <[email protected]> wrote in
news:9%[email protected]:
> I just found that some circular have logic-defying efficiency.
>
> For example, dewalt DW368K specification says 15 Amps motor, and the
> max output is 2200 Watt. However, the input power is 15 Amps x 120V =
> 1800 Watt. How could it consume 1800W of electricity and produce 2200W
> of power? It must have an effiiciency exceeding 100%!
If you take the electrical energy input, and add to that the rotational
energy stored in the blade, etc (all of which have momentum), then you
can easily get 2200 watts. In fact, depending on how fast you extract
the rotational energy you can get pretty much any wattage value you
like.
Of course, none of that is of any value whatsoever in the real world.
John
GigaNews wrote:
> Seriously, I have always wondered about this. Someone once told me this
> was a 'peak' horsepower.
>
> I must admit that although I did well in my EE classes, that was years ago
> and even then I always viewed electricity as being something close to
> black magic and voodoo.
>
> Does anybody have an explanation of how they get away with this?
No or poorly defined standards. Different ratings for different purposes.
"Amps" for how big a circuit it needs. "Watts" for marketing.
"Horsepower" the same.
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
Those are run of the mill efficiancies for woodworking tools. When they
crack the 200 percent effieciency mark it will make news.
John
peter wrote:
> I just found that some circular have logic-defying efficiency.
>
> For example, dewalt DW368K specification says 15 Amps motor, and the max
> output is 2200 Watt. However, the input power is 15 Amps x 120V = 1800 Watt.
> How could it consume 1800W of electricity and produce 2200W of power? It
> must have an effiiciency exceeding 100%!
>
> Another example: Milwaukee 6391 has a 15 Amp motor and claim the saw has 3
> 1/4 horsepower.
> Since 1 horsepower = 746 W, 3.25 HP = 2424.5 Watt. It is even more efficient
> than the dewalt!!
>
> Why hasn't these more than 100% efficient machines made the headlines?
>
>
On Sat, 24 Jul 2004 00:54:49 GMT, "Jim Giblin"
<[email protected]> wrote:
|Physics 101, not!
Marketing 101, Yes!
|
|"peter" <[email protected]> wrote in message
|news:9%[email protected]...
|> I just found that some circular have logic-defying efficiency.
|>
|> For example, dewalt DW368K specification says 15 Amps motor, and the max
|> output is 2200 Watt. However, the input power is 15 Amps x 120V = 1800
|Watt.
|> How could it consume 1800W of electricity and produce 2200W of power? It
|> must have an effiiciency exceeding 100%!
|>
|> Another example: Milwaukee 6391 has a 15 Amp motor and claim the saw has 3
|> 1/4 horsepower.
|> Since 1 horsepower = 746 W, 3.25 HP = 2424.5 Watt. It is even more
|efficient
|> than the dewalt!!
|>
|> Why hasn't these more than 100% efficient machines made the headlines?
|>
|>
|
In article <9%[email protected]>,
peter <[email protected]> wrote:
>I just found that some circular have logic-defying efficiency.
>
>For example, dewalt DW368K specification says 15 Amps motor, and the max
>output is 2200 Watt. However, the input power is 15 Amps x 120V = 1800 Watt.
>How could it consume 1800W of electricity and produce 2200W of power? It
>must have an effiiciency exceeding 100%!
>
>Another example: Milwaukee 6391 has a 15 Amp motor and claim the saw has 3
>1/4 horsepower.
>Since 1 horsepower = 746 W, 3.25 HP = 2424.5 Watt. It is even more efficient
>than the dewalt!!
>
>Why hasn't these more than 100% efficient machines made the headlines?
>
>
Ho hum, those 3 hp saws and routers have all been pushed to the back
pages by the 5 and 6HP shop vacuums.
--
Larry Wasserman Baltimore, Maryland
[email protected]
Physics 101, not!
"peter" <[email protected]> wrote in message
news:9%[email protected]...
> I just found that some circular have logic-defying efficiency.
>
> For example, dewalt DW368K specification says 15 Amps motor, and the max
> output is 2200 Watt. However, the input power is 15 Amps x 120V = 1800
Watt.
> How could it consume 1800W of electricity and produce 2200W of power? It
> must have an effiiciency exceeding 100%!
>
> Another example: Milwaukee 6391 has a 15 Amp motor and claim the saw has 3
> 1/4 horsepower.
> Since 1 horsepower = 746 W, 3.25 HP = 2424.5 Watt. It is even more
efficient
> than the dewalt!!
>
> Why hasn't these more than 100% efficient machines made the headlines?
>
>
I think you may be onto something there...
<[email protected]> wrote in message
news:[email protected]...
> On Thu, 22 Jul 2004 10:30:03 -0400, "GigaNews" <[email protected]>
> wrote:
>
> >Seriously, I have always wondered about this. Someone once told me this
was
> >a 'peak' horsepower.
> >
> >I must admit that although I did well in my EE classes, that was years
ago
> >and even then I always viewed electricity as being something close to
black
> >magic and voodoo.
> >
> >Does anybody have an explanation of how they get away with this?
> >
>
>
> they just lie....