Alt-BEAM Archive
Message #07271
To: beam@sgiblab.sgi.com
From: "Timothy Flytcher" flytch@hotmail.com
Date: Mon, 01 Nov 1999 20:43:37 PST
Subject: [alt-beam] Re: aquabots - 'sealed' motor
Most light bulbs don't have a lower pressure at all they just use a inert
gas...Cheaper than pulling a vacuum... The problem I see is the fixed
envelope size... the light bulb displaces the same amount of water no matter
what temp it is...
Timothy...
>Well the problem with light bulbs are that there's a vacuum inside, so
>I don't think yell be getting much bouynacy out of them but I could be
>wrong!
>
>Jacob Booth wrote:
> >
> > I have a filter pump for my aquarium which has the coils in a sealed
> > plastic ring or tub. The armature is a multi-poled magnet also sealed in
> > plastic which 'floats' inside the plastic ring. I guess it works more
>like
> > a stepper motor (would need circuitry to do the job of the commutator)
>but
> > is perfectly watertight (well, close enough :). Another bonus is NO wear
>as
> > it uses no bearings. The combination of magnetic field and moving water
> > enables the armature (should this be just called a rotor?) to 'float'
> > inside the ring and rotate. It is designed to be fully submerged. I am
> > thinking of doing something like this as a proof of theory for a
>waterproof
> > motor for myself. I doubt anything home made would be very efficient at
>all
> > though. Does efficient matter when we have other things like water
>friction
> > to worry about? :)
> >
> > warning: bad ascii image below:
> >
> > -- || -- A: multi-poled rotor
> > || ---- || B: sealed coil assembly
> > || | A| || x: water filled void
> > || |__| ||
> > ||___x__||
> > |____B___|
> >
> > picture a film canister sized water filled void, and the rotor as the
>roll
> > of film size. I want to make a small one!
> >
> > Oh, and another thought... what about using a small light bulb for a
> > buoyancy device? would it make any difference on its own when turned on
>(eg
> > heat up the low pressure gas inside the bulb) compared to off? A bit
>power
> > hungry, but a different idea! Maybe if the gas space in the bulb is too
> > small it could be used to heat up a larger container of air for example.
> > Would it be better to expose the bulb outside the bot, or have it inside
> > the sealed airspace inside the bot? Anyone thought about this before or
> > tried it? let me know!
> >
> > Cheers
> > Jacob
> > ------------------------------------------------------------------
> > Jacob Booth BIS, MCP Web http://www.its.mary.acu.edu.au/
> > IT Services Email j.booth@mary.acu.edu.au
> > Phone (02) 97392235 Fax (02) 97392924
______________________________________________________
7272 Mon, 1 Nov 1999 23:03:24 -0600 [alt-beam] aibo "beam" "Jarrell Clark" http://home.cnet.com/consumerelectronics/0-3622-7-1426115.html?tag=st.cn.1fd
2.tlpg.3622-7-1426115
saw this on cnet. for those that care
-_-_-_-_
A wise man once told me "Hey! How did you get past the dogs?"
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