How long will this term apply to the measurement of power? Sort of obsolete isn’t it? Anyway, how big of a horse, what kind? Isn’t it time for a new more relevant term? Something we can all relate to… like the energy to power a shopping cart through Wal-mart during Holiday shopping? Any other suggestions?
Edited 11/1/2009 8:30 pm by RJT
Replies
For power tools, I don't pay any attention to horsepower at all. Often, the HP rating is calculated to get the max rating, which is at startup and only lasts for a split second. That's why a router can be 3-1/4HP. I look at amps when comparing power.
and www.flairwoodwork.spaces.live.com)
- Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
>Something we can all relate to... like the energy to power a shopping cart through Wal-mart during Holiday shopping<
Do you mean the power expended by an over weight over stressed mom forcing her shopping cart through the packed crowds at Wal-mart during Holiday shopping ? Now that is serious power. Too bad there can't be miniature power generators connected to all those carts all the time. We would be selling power to Canada !
▪ One mechanical horsepower of 550 foot-pounds per second is equivalent to 745.7 watts.
(That's the ability to raising 550 lb of weight vertically on a rope one foot for every second.)
▪ A metric horsepower of 75 kgf-m per second is equivalent to 735.499 watts.
▪ One horsepower for rating electric motors is equal to 746 watts.
That sort of horse.
The standard for the civilized world, you know where they eat croissants and espresso and take two hour lunches and discuss things besides who did what on some "reality" show, is the Watt. Hey looky there on our electric bill they are measuring things in Killo watt hours. Don't tell " the regular people " there will be lynchings in the streets. Information like that can be safely handled only by scientists and astronauts. That sort of bear.
There may, however, be hope for us yet. In another century or so.
Volts x amps = watts
Then there is the little over site by the 5 horse power running on 120 volts vacuum cleaner makers ( which is absurd ) that yes it might be able to do that for a micro second
it works out to very roughly 31 amps ! ! ! On a 15 or 20 amp breaker ? ? ? How does that work ?
But the motors rated as such for a table saw running on 220 volts or 460 volts three phase can do it all day.
Wouldn't that be 550 lb x 5 = 2,750 pounds vertically one foot per second. That's some vacuum cleaner ! ! !
That sort of horse. ( You know the ones sewn together and stuffed with straw. )
The standard unit of energy in the International System of Units (SI) is the joule (J), equal to one watt second. Inversely, one watt is equal to 1 J/s. One kilowatt hour is 3.6 megajoules
Not sure if the Euro power bills are measured in joules or what.
Lataxe will you lend a hand with that one ?
roc
Give me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
Edited 11/1/2009 11:00 pm by roc
Roc,
Perhaps them vacuum cleaner things are using different kinds of scales, such as shetland ponies rather than Clydesdales or Shires? Hey, everything is allowed in marketing, which is "the telling of lies that are good". (Good for the market which, as you know, trumps all other schemes of bad and good).
However, even in Yp some vestage of the Olde Schemes remain in the literature, as the English adverts describing those fine German Scheppach WW machines that grace my shed all give the power figures in both horsepower and kilowatts. The manuals, however, use only the kilowatt figures.
They do tend to be honest, also, by giving two figures: the power input and the output. For example, the bandsaw manual states that the 230 volt 50 cycle/second version consumes 2.3kw and outputs 1.5kw. The figures must meet certain objective schemes for measurement - of constant rather than startup power in this case. Those dang Ypean bureaucrats!
There are many other values given: for the required breaker protection rate, motor rotation speed and much more. Notice, though, that there are no shetland pony or other inflationary measurement schemes to increase the appeal to trooly-individualistical men or wimmin who want only The Biggest & Most Powfl. How do our Ypean egos survive this enforced dose of objective reality!
****
Now, I must deal with Andy, who fails to understand the need of US woodworkers for Absolute Stability, as Created at the Dawn of Civilisation (1776).
As the measurement schemes were imperial at the time of what they like to call The Revolution (actually a local rebellion by ungrateful beneficiaries of King George's largesse) so the imperial schemes must stay. Change to more logical systems such as metric will only confuse them, as would the evolution of tablesaws beyond the C19th model*. Metric is..... well .....unconstitutional!
Now, where is my copy of Milton Friedman? I am obviously in need of some shock doctrine.
Lataxe, probably in need of cutting up with his own bandsaw and feeding to the dawgs.
* The Original & Best TS design comes inclusive of a random kickbacker (again to please the individualistic-men, who reserve the right to damage themselves severely, as well as to pay heavily for having the damage mended) and also the non-inclusion of a sliding table (dang new-fangled foreign nonsense not needed by real woodworkers who instead make large plywood crosscut boxes from scraps instead, in the pioneer fashion).
>How do our Ypean egos survive this enforced dose of objective reality!<Ha, ha, ha, aaahhhh, Ha, ha, ha, haQuite well from what I have seen.> enforced <Next I suppose you are going to tell me that it is enforced upon everyone to have a health care system that actually works and care is enforced upon people too sick to work to be treated without loosing everything they have.nah you're pulling my leg. That would be terrible.rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
>Change to more logical systems such as metric will only confuse them,And!? I had to go through it when I was just old enough to understand the old system. Now I'm thoroughly messed up. I measure indoor and body temp in F and measure water and outdoor temp in C, my GPS talks to me in miles while I'm ticketed in klicks, and most woodworking is done in inches and feet. Someone else needs to share my pain. :)Andy
Try a few PINTS. Those should ease your pain. (I recommend Bombadier.)
>Try a few PINTSPint?! Is that 14.9oz? Cause that's the internationally recognized size of a tall, dark can of heaven with the widget inside?
Roc,<!----><!----><!---->
You have a pretty good grasp of electrical theory. I'd like to add a little, if I may.
Volts x Amps = watts in a Direct Current circuit, that is true. An AC circuit requires magnitization. Watts are heat, which is work, which is "real power". But the magnitization produces no work, just the required magnetic field. The "power", (and I use the term loosely), used to magnetize is known as voltamps reactive, or VARS. If you multiply the nameplate volts and amps together you get VA, or apparent power.
Vectorally, the real power, [W], is plotted on the X axis and the reactive power, [VARS] on the Y axis. The resultant vector is the apparent power, [VA].The cosine of the angle between the apparent power and the real power is the power factor, [pf].
So, if you take the apparent power, [VA] and multiply by the pf you get real power, [W]. You can assume in electric induction motor driven power tools a pf between .65 and .85. So, suppose you have an AC induction motor with 120 [V] and 15 [A] on the nameplate. Assuming a .85 pf then the real power, the ability to do work, would be 120 x 15 x .85 = 1530 [W], or about 1530 / 746 = 2 [HP].<!----><!---->
Or more simply, you can’t just multiply volts x amps and get HP in AC circuits. You can think about VARS like the bubbles in beer. You can have beer without bubbles, but it sure is nicer when you have them…<!----><!---->
Sorry for getting overly technical here, a 37 year habit is hard to break…<!----><!---->
>An AC circuit requires magnitization<Beautifully explained thank you. I only read about it and you guys are the only chance I get to regurgitate it.>Magnetization<Surely we are talking electromotive force , emf, rotating around the axis of the windings wire.Same thing in practice considering the iron core I suppose.>loss<
that was why I back pedaled with my "very roughly " attachment to the amperage comment. Your way of saying it is much more accurate. Loss of volts and amps due to heat from resistance and having to produce the stator field(s).Have I got it now or shall I shut up and go reread my 1943 physics book. I love that book by the way. Wish I had not listened to the counselor in my high school when she said "oh you don't want to take physics that is too hard; take biology in stead ".grumble grumble. I had no idea what physics even was back then.PS: mitochondria are our friendsrocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )Edited 11/2/2009 1:21 pm by roc <!-- ROC2013 -->
Edited 11/2/2009 1:22 pm by roc
One of MY committee members keeps yelling at me that the effective power is fairly simple to guesstimate. The basic formula used to be Peak-to-peak power * .707 to get the RMS power output of an AC circuit. RMS is an acronym for Root Mean Squared. Regards,RonAs God is my witness, I thought turkeys could fly!
-Arthur Carlson
>One of MY committee members keeps yelling at me that the effective power is fairly simple to guesstimate. The basic formula used to be Peak-to-peak power * .707 to get the RMS power output of an AC circuit. RMS is an acronym for Root Mean Squared.<My first reaction was my usual curmudgeonness: that person is a bit rusty are they an EE ? Sad state of affairs. Does any thing get done with such "help" full members ?Maybe I am missing the whole point but for the readers here, as I understand it Peak-to-peak is the highest VOLTAGE on positive side above the zero line and the highest VOLTAGE on negative side bellow the zero line on the graph screen of an oscilloscope. Until this moment I thought of voltage as voltage and RMS pertaining to voltage.After a bit of a lounge on the couch I have shifted to be of the opinion that very roughly it seems reasonable now to do as he/she said.What are your thoughts ? I just had a delicious mealhttp://www.foodandwine.com/recipes/beef-stew-in-red-wine-saucewith a nice Bordeaux wine, cheese, chocolate and haven't made it to the coffee yet so I am feeling very agreeably agreeable indeed.rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
Edited 11/8/2009 11:25 pm by roc
>Sort of obsolete isn't it? Anyway, how big of a horse, what kind? Isn't it time for a new more relevant term?
We should be more concerned with converting that last country from using inches, miles and farenheit toward the decimal systems of SI units. ;)
Andy
An inch, if I do recall correctly, was originally defined as the distance from the first to second knuckle (of the index finger?)Chris @ http://www.flairwoodworks.com and http://www.flairwoodwork.spaces.live.com)
- Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Youse guys are all getting too testicle for me.How about using hamsters on a treadmill to measure power.I like the way the Chinese manufacturers handle the motor horsepower problem.They simply put a sticker of the required horsepower on the motorI started out with nothing...and I still have most of it left!
Personally, I like the definition for "taxable horsepower".
"They simply put a sticker of the required horsepower on the motor"That's funny!BB
>An inch, if I do recall correctly, was originally defined as the distance from the first to second knuckle (of the index finger?)Seems kind of arbitrary. I'm going to define the Brap. That will be the distance my fart travels in one second. I will divide it into seventeen parts and put it on a metal ruler. If I can sell that tool to Henry Ford, his countrymen will use it exclusively for the next 80 years...;)
Andy
How are you going to calibrate this thing? Special constant meal the night before maybe. Curry, onions, baked beans.......wotI started out with nothing...and I still have most of it left!
Egg salad sandwiches and beer.
................................................
Men will never be free until the last king is strangled with the entrails of the last priest.~ Denis Diderot
Guys,I am starting to get confused by all these power definitions, so I thought its time to get back to basics.Power, be it horse power, watts or hampsters per revolutions is the product of [X times picograms by 10 to the 12th power and the distance traveled by light in 1/299 792 458 of a time interval equal to the duration of 9,192,631,770 periods of the radiations associated with the transition between the two hyperfine levels of the ground state of cesium133] and the product of [a flow that - if maintained along two parallel conductors of negligible cross section and infinite length, placed the distance light travels in 1/299 792 458 of the afore said time interval equal to the duration of 9,192,631,770 periods of the radiation associated with the transition between the hyperfine levels of of the ground state of cesium133,apart, in a vacuum and would cause each to produce a force of 10 to the minus 7 newtons, per the distance light travels in 1/299 792 458 secs of length} by a flow that - if maintained along two parallel conductors of negligible cross section and infinite length, placed the distance light travels in 1/299 792 458 of the afore said time interval equal to the duration of 9,192,631,770 periods of the radiation associated with the transition between the hyperfine levels of of the ground state of cesium133,apart, in a vacuum and would cause each to produce a force of 10 to the minus 7 newtons, per the distance light travels in 1/299 792 458 secs of length.This is about as simply as I can put it and I hope it clears up any confusions with you, as I had.Don't forget, guys, that you have to apply your own conversion constant to get HP, watts or hampsters/rev.wot (not watt)I started out with nothing...and I still have most of it left!
You use the term "hyperfine" repeatedly in your post. Isn't this a relatively ambiguous term, as much as "horsepower"? "Superfine" as compared to what? As in" "she's so 'fine' my 409"? or a granular distinction, or a cosmetic thing.... or as in suave? Please elaborate.
Hi RJTTick all of the above as well as I'll be fine, a fine line and the weather's fine. Vaguely recalling from my junior high school physics from the 50's I think it has something to do with the 55th electron being the only electron in the outermost shell and the energy state of such a valence electron to be split by a fine structure or hyperfine arising from the magnetic interaction of the electron spin with the inner electrons......sort of.Basically its a very stable oscillation with a cycle being 1/912 631 770th of a second, which is about the same period of time from a red light turning green and the clown behind you starting to blow his horn.By the way the cesium atomic clock has an accuracy of about 1 second in 1.4 million years.Also all that previous post cr*p basically means - P=VIwotI started out with nothing...and I still have most of it left!
"By the way the cesium atomic clock has an accuracy of one second in 1.4 million years."
That doesn't sound very accurate to me. Don't you mean inaccuracy?
Right again mate! Put it down to the fact that I have had too many gray cells predated (as in predator) by single malt. This kinda blows the theory that vegetables are good for you right out of the water eh!wotI started out with nothing...and I still have most of it left!
>How are you going to calibrate this thing? One regulation-size mayonaise and peanut butter sarnie.
Andy,How many Nabins per Brap? I've defined a Nabin as the distance from the nostril to the brain.Chris @ http://www.flairwoodworks.com and http://www.flairwoodwork.spaces.live.com)
- Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
17
Jest idle musings.... with many car manufactures changing their engine power output measurement to Kilowatts and with the increasing power of car sound system amplifiers now in the kilowatt range, maybe, to avoid confusion, amplifier power should be changed to horse power. Just imagine a 2 or 3 horsepower system trying to (boom...boom...boom) pound the pickets offen your front fence.wotI started out with nothing...and I still have most of it left!
My wife harangues at me when I mention it, but when a real loud car goes by I usually mutter that I'd like to add to the noise by lobbing a hand genade into it. Yes, I know that it isn't a very good thought.
Edited 11/11/2009 11:43 am ET by Tinkerer3
>when a real loud car goes by I usually mutter that I'd like to add to to the noise by lobbing a hand genade into it. Yes, I know that it isn't a very good thought.<I say go for it. It isn't a very good_________( fill in the blank ) when people keep the neighbor hood awake with said noise while they sit out in the street in their car at two am. Some people need to get sleep so they can go to work early in the morning and some people need to get " spanked " for making loud noise at two in the morning.I believe in " spanking " spoiled children who do that.PS: often those spoiled children are carrying nine millimeters so the grenade seems prudent and appropriate.PPS: an early riser has got to do what an early riser 's gotta do.PPPS: I bet the character in the recent movie GTO with Clint Eastwood would agree. I haven't watched the movie. I try not to expose my brain to things that might push it over the edge.Ommmmm Ommmmm Ommmmm . . .: )PPPPS: I go into work later so I can stay up late eating chocolate, typing in chat rooms at two in the morning ( it is not three am here ) and cussing the boom boom boys for yaall tryin' to sleep.rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
Edited 11/11/2009 4:04 am by roc
"need to get " spanked " ooooooh roc, I love it when you talk dirty.I'm sure that the sociologists could give you 127 reasons why these kids need to express themselves with 9mms and keeping good folks like us awake. and I'm surprised that someone like yourself, with the soul of a poet, would say such things about those little ####.wotI started out with nothing...and I still have most of it left!
>the sociologists could give you 127 reasons why these kids need to express themselves <Yes but I want to see how long the sociologist Granny of the Beverly Hillbillies would put up with them.I bet we could use the 1/299 792 458 of a time interval on that one to.I wouldn't want to be on the receiving end of Granny Power either. Not when it is connected up to a willow switch. That's the kind o' spankin' I'm talkin' about. Nice clean attitude adjustment. Not sure about your dirty kind. Guess I will have to leave that to you.The grenade was just to wake 'em up from their little brain fart before THE Granny is let loose on 'em.rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
>Not when it is connected up to a willow switch.<
Probably what is needed to swing the behaviour pendulum back.Bring back the Grannies who fed you good but when required, beat you til you bleed,then beat you for bleeding.Sometimes I think Uncle Jed's rifle would be a more preferable option.wotI started out with nothing...and I still have most of it left!
Edited 11/12/2009 6:27 am ET by wotnow
>Uncle Jed's rifle <Nah he is too soft hearted. He just uses it for show and to hunt oil deposits.Granny on the other hand . . . her shot gun is loaded with rock salt in case one o' them youngins makes the mistake of runnin from the willow switch. Granny is going to win one way or t'other. One just learns to TAKE what is i-n-e-v-i-t-a-b-l-y comin' to yah.rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
rocAlthough this isn't exactly 'horsepower' it's sorta in the electrical ballpark and I thought as a technical guy you might enjoy it.My daughter from back home sent it. A Tamworth farm wife called the local phone company to report her telephone failed to ring when her friends called and that on the few occasions, when it did ring, her dog always moaned right before the phone rang. The telephone repairman proceeded to the scene, curious to see this psychic dog or senile lady. He climbed a telephone pole, hooked in his test set, and dialled the subscribers' house. The phone didn't ring right away, but then the dog moaned and the telephone began to ring. Climbing down from the pole, the telephone repairman found:
1. The dog was tied to the telephone system's ground wire with a steel chain and collar.
2. The wire connection to the ground rod was loose.
3. The dog was receiving 90 volts of signalling current when the number was called.
4. After a couple of jolts, the dog would start moaning and then urinate.
5. The wet ground would complete the circuit, thus causing the phone to ring.
This demonstrates that some problems CAN be fixed by pi**ing and moaning. So, carry on as usual!!wotI started out with nothing...and I still have most of it left!
AAAaaaahhhhooooooHa, ha, ha, aaahhhh, Ha, ha, ha, ha>pi**ing and moaning<Just gets ME further into trouble. Doesn't mean I am going to stop doing it though.Nice story. Poor woofer . . . I feel sorry for him.: (rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
>Poor woofer . . . I feel sorry for him.<Feel sorrier for some dogs at home. Local newsagent, sick of dogs urinating on the corner of his shop, stuck some foil around the corner then hooked up an electric fence.I bet that smarted!wotI started out with nothing...and I still have most of it left!
I've been working on a focusable electro-magnetic pulse beam generator, hand-held, of course. Doesn't take too many induced volts to fry their little brains (the semiconductors, not the drivers). So far, I've opted to ride a bus to another neighborhood for testing, though. ;-)
Hold onto those thoughts Tink, keep the dream alive and remember that your wife is only doing the job that wives are supposed to do.wotI started out with nothing...and I still have most of it left!
When I mention "hand grenade," please believe me that I have no murderous thoughts. Probably more like I just wish that radio or what ever would self destruct. In smoke.
>fry their little brains (the semiconductors, not the drivers)<Oh it was perfectly clear you didn't mean the driver. If they had even a little bit of brain they wouldn't be listening to something that sounds like that, that loud, at that time of night. BOOM buzz, BOOM buzz, BOOM buzz.They have got to have heads that are solid bone clear through just to survive it.>When I mention "hand grenade," please believe me that I have no murderous thoughts<Yah, yah I hear ya. Sure is a good thing they don't sell grenades in vending machines huh ?rocGive me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )
Edited 11/13/2009 12:22 am by roc
Tink>When I mention "hand grenade," please believe me that I have no murderous thoughts.< Sometimes the 'medicine' tastes a little bitter, but when it is prescribed for the right 'patients' ie wastes' of space and oxygen thieves, then IT WAS prescribed correctly. Don't sweat it!wotI started out with nothing...and I still have most of it left!
Andy.. Geeee I think nothing to do with inches or metric!
.707 is just the sin 45 deg! I think. OK, so it is
sin(45 degrees) = 0.707106781
Too much information! What has search overload done to us . . . anyone seen the commercials for Ask.com (I think)? That's you guys! Are you honestly trying to tell me that my ShopVac isn't way, WAAAAYYY more powerful than my bandsaw?Brian
BrianWith apologies to Dragnet, "were giving you the facts maam, just the facts">Are you honestly trying to tell me that my ShopVac isn't way, WAAAAYYY more powerful than my bandsaw?< Only if you are running it over two phases of a three phase supply.wotI started out with nothing...and I still have most of it left!
A general rule of thumb is that a person in good condition can steadily produce about 1/10 horsepower continuously, mostly using their leg muscles in some fairly efficient manner like bike riding.
Shop Manager for FWW Magazine, 1998 to 2007
I'm afraid "rule of thumb" doesn't cut it for these young turks -- they probably don't get the reference. Traditional measurements were based on measuring without implements. An inch was the width of a thumb (still is "pouce" in French), a foot was the length of a foot, you measured a horse's height in hands, and power in what every countryman understood -- the number of horses needed to do the job. The system didn't always work perfectly. A man's yard usually came up short :^[.
Jim
According to some pundits, both horses and men will go extinct around December 21, 2012. So, why change now? ;-)
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