Author Topic: Watts that? Hertz much?  (Read 1281 times)

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12AX7

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Watts that? Hertz much?
« on: February 23, 2006, 06:36:20 AM »
It's not always how much you have.   Sometimes it's all about knowing how to use what you have.


If one average strong horse can pull a stump out of the ground ..   shouldn't we expect the same out of our 3 to 5 hps lawnmowers?


I suppose with them hooked to a large enough winch..  maybe.


but that old fella just  might be able to do it in a few moments.  He'd be eating hay and giving you fuel (once dried out) and you'd still be adding gas to your lawnboy.


DO you really think your 5hp power tool (table saw.. router..  air compressor) really give you 5 of them big fellas working?  


Is there any relationship between cogging and output?


It's said that for power to be extracted from flowing water "head" is required.

Is this true?   or is it a "truth" based on old technology?


Now where is this headed?

I've been doing the "lurking" thing here for over a year.  Signed up not that long ago and have enjoyed reading others posts.. comments.. stories and diaries.

Sometimes feel a bit "cheated" when I find others that have no diary entries ..stories or files to peak at.

So not wanting to throw stones at my own windows....


Oh yeah,   RE..   reminds me    I live REALLY Darn close to a small river with an almost ideal location for a "paddlewheel"   THere's power in them there currents.  Plenty of eddies too!  Been collecting stuff and talking for years, pretty soon it's going to be time to crap or get off the pot!

« Last Edit: February 23, 2006, 06:36:20 AM by (unknown) »

willib

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Re: Watts that? Hertz much?
« Reply #1 on: February 23, 2006, 02:11:10 AM »
having head in you water system does help , but in my opinion is not necessary , as one paddle wheel is good , two paddle wheels is better , or twice as good, lol, ect..

I  recognize your vacuume tube monicker ;)
« Last Edit: February 23, 2006, 02:11:10 AM by willib »
Carpe Ventum (Seize the Wind)

drdongle

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Re: Watts that? Hertz much?
« Reply #2 on: February 23, 2006, 05:29:02 AM »
With all these things it's a ballancing act. In a water way with a low drop a large volume can (with the right equipment) make up for it, if you have a small amount of water a large drop can make up for that.

I on the other hand I have small streams with very little drop, so I'm screwed.
« Last Edit: February 23, 2006, 05:29:02 AM by drdongle »

Chagrin

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Re: Watts that? Hertz much?
« Reply #3 on: February 23, 2006, 07:02:56 AM »
I would fully expect that a lawnmower engine could pull a stump out of the ground. Heck, a little 1.5V DC motor could do it, given enough time and gearing.


"Power" concerns a rate at which force can be applied. Now, you give me a nice long lever and I can pull a stump out too, but does that mean I have as much power as a horse? No.


Just for reference, a good round figure for how much power the average human has is about 300W, but only over a timespan of about 5 minutes (before you pass out or have a heart attack). I read about a college group trying to build a human-powered helicopter and their limit was 350W from a professional bicyclist, but they needed a medical team on-site for when the experiment took place because that cyclist was going to be pushing himself pretty hard. Apparently the only person able to achieve 350W had a heart attack after the test.


If you really wanted to compare a horse to a lawnmower engine you'd need to pick a task other than pulling stumps since that deals more with force at any given instant than anything else. Dragging stumps across the ground, perhaps ... do you think a one horsepower engine could drag a stump along the ground as fast or faster than a horse? I suspect it'd be kinda close.

« Last Edit: February 23, 2006, 07:02:56 AM by Chagrin »

coldspot

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Re: Watts that? Hertz much?
« Reply #4 on: February 23, 2006, 09:01:16 AM »
HP=Wh

   --

33,000*Eff

W=weight lifted, in pounds (Lb)

h=height lifted, in feet per minute (ft/min)

Eff=efficiency, in percent (%)


Or


Hp=TN

   --

   5252


T=Torque in (ftLb)

N=speed in Rpm

« Last Edit: February 23, 2006, 09:01:16 AM by coldspot »
$0.02

MelTx

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Re: Watts that? Hertz much?
« Reply #5 on: February 23, 2006, 03:08:39 PM »


   And it is written "Thou shall not tell the horse that a lawnmower is more powerful than him.It might Hertz his feelings."  

   So let it be written so let it be done..........
« Last Edit: February 23, 2006, 03:08:39 PM by MelTx »

finnsawyer

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Re: Watts that? Hertz much?
« Reply #6 on: February 25, 2006, 10:05:54 AM »
Flowing water has momentum and carries energy just like the wind.  If you force the water through a funnel shaped gate you can speed it up and gain more energy.  There was a posting here some time ago about a river in Germany where that was done with apparently amazing results.  The river also had a standard head drop generating system for comparison.


I also recognized the vacuum tube designation from the old days.

« Last Edit: February 25, 2006, 10:05:54 AM by finnsawyer »

roddy

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Re: Watts that? Hertz much?
« Reply #7 on: March 23, 2006, 11:33:32 AM »
please help me find this german river posting.


Thanks


Roddy

« Last Edit: March 23, 2006, 11:33:32 AM by roddy »