Alt-BEAM Archive
Message #07298
To: beam@sgiblab.sgi.com
From: Evan Dudzik evandude@yahoo.com
Date: Tue, 2 Nov 1999 17:12:11 -0800 (PST)
Subject: [alt-beam] Re: directional antenna?
okay, then, what is fast enough????? anything???
--- Bob Shannon wrote:
> Radio waves move at a foot per nanosecond, TTL is
> not
> fast enough.
>
> But for BEAM applications, I'd reccomend using a
> ferrite loopstick
> antenna, like is found in hand-held AM radios.
>
> Evan Dudzik wrote:
>
> > does anyone have any ideas on how to build a
> > unidirectional antenna? this would be great for
> homing
> > in on RF signals... otherwise, i have another
> idea.
> > take three antennas, and place one in the center
> of
> > the bot... take the next two and place them at
> the
> > left and right sides of the bot. now, have a
> beacon
> > set up that transmits signals... it just has to
> > transmit a signal, wait for like a second, and
> then
> > trasnmit another... the robot will have its
> central
> > antenna on at all times, waiting for that first
> > signal. when it recieves it, it turns on the
> other
> > two recieving antennas... when the signal comes,
> it
> > will reach one antenna BEFORE the other because
> that
> > antenna is closer. The difference between times
> would
> > be REALLY short, so the bot would have to have
> some
> > quick detecting circuitry (TTL... isnt that really
> > fast? fast enough?) this whole thing is kinda how
> our
> > ears work, sound reaches one side before the
> other.
> > any ideas on circuitry? or whether this thing
> would
> > even work? it would be good to help a bot home in
> on
> > its charging station... or other uses. anyway,
> > thanks.
> >
> > =====
> > +------------------------+
> > |http://surf.to/photovore|
> > |Photovores online! |
> > |Evandude Dudzik |
> > +------------------------+
> > __________________________________________________
> > Do You Yahoo!?
> > Bid and sell for free at http://auctions.yahoo.com
>
>
=====
+------------------------+
|http://surf.to/photovore|
|Photovores online! |
|Evandude Dudzik |
+------------------------+
__________________________________________________
Do You Yahoo!?
Bid and sell for free at http://auctions.yahoo.com
7299 Tue, 2 Nov 1999 17:12:46 -0800 [alt-beam] Re: aquabots - 'sealed' motor "'beam@sgiblab.sgi.com'" Wilf Rigter
There was a post not long ago of a sub-bot that used wax heated through it's
solid/liquid phase to change the buoyancy.
Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
tel: (604)590-7493
fax: (604)590-3411
> -----Original Message-----
> From: Bob Shannon [SMTP:bshannon@tiac.net]
> Sent: Tuesday, November 02, 1999 4:27 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: aquabots - 'sealed' motor
>
> Wouldn't it be a lot more efficient to drive a bimetalic strip attached to
> a bellows?
>
> Store up power, then activate the ballast bladder, change depth, then as
> the
> strip recovers you return to your trimed depth.
>
> Asking the heat of a light bulb to change the density of a gas
> sufficiently to
> displace enough water to matter is not an efficient process.
>
> Benjamin Edward Hitchcock wrote:
>
> > ----- Forwarded message from Wilf Rigter -----
> > Using a light bulb to change buoyancy won't work since buoyancy is
> affected
> > by the displacement of water with a volume of lower density. So the
> rigid
> > glass bulb is the problem. A bladder filled with an incompressible
> substance
> > which changes volume and density as it is heated should work.
> >
> > alright!
> >
> > ---
> >
> > I love it! Using a lightbulb to change buoyancy! Fantastic! There is
> a
> > way to do this - put a partially inflated balloon around the lightbulb.
> > This will make the whole assembly watertight as well, and make a cool
> > coloured 'glow' when the device is on. Maybe you could use a magnetic
> > coil on the bottom of the cylinder attached to the mains, and have
> another
> > coil on the bottom of your bot. This would charge up a capacitor, and
> > coupled to a solar engine would make the bot sit on the bottom chanrging
> > up, then light its 'engine' and drift up to the stars!
> >
> > VERY elegant.
> >
> > Nice idea!
> >
> > Ben
7300 Wed, 03 Nov 1999 21:24:30 -0400 [alt-beam] Re: aquabots - 'sealed' motor alt-beam@egroups.com michael.hirtle@ns.sympatico.ca (Michael Hirtle) If u have problems with alge u could get a alge eater and put it in the tank
with your bots, but the bot may kill the fish
Wilf Rigter wrote:
> There was a post not long ago of a sub-bot that used wax heated through it's
> solid/liquid phase to change the buoyancy.
>
> Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
> tel: (604)590-7493
> fax: (604)590-3411
>
> > -----Original Message-----
> > From: Bob Shannon [SMTP:bshannon@tiac.net]
> > Sent: Tuesday, November 02, 1999 4:27 PM
> > To: beam@sgiblab.sgi.com
> > Subject: Re: aquabots - 'sealed' motor
> >
> > Wouldn't it be a lot more efficient to drive a bimetalic strip attached to
> > a bellows?
> >
> > Store up power, then activate the ballast bladder, change depth, then as
> > the
> > strip recovers you return to your trimed depth.
> >
> > Asking the heat of a light bulb to change the density of a gas
> > sufficiently to
> > displace enough water to matter is not an efficient process.
> >
> > Benjamin Edward Hitchcock wrote:
> >
> > > ----- Forwarded message from Wilf Rigter -----
> > > Using a light bulb to change buoyancy won't work since buoyancy is
> > affected
> > > by the displacement of water with a volume of lower density. So the
> > rigid
> > > glass bulb is the problem. A bladder filled with an incompressible
> > substance
> > > which changes volume and density as it is heated should work.
> > >
> > > alright!
> > >
> > > ---
> > >
> > > I love it! Using a lightbulb to change buoyancy! Fantastic! There is
> > a
> > > way to do this - put a partially inflated balloon around the lightbulb.
> > > This will make the whole assembly watertight as well, and make a cool
> > > coloured 'glow' when the device is on. Maybe you could use a magnetic
> > > coil on the bottom of the cylinder attached to the mains, and have
> > another
> > > coil on the bottom of your bot. This would charge up a capacitor, and
> > > coupled to a solar engine would make the bot sit on the bottom chanrging
> > > up, then light its 'engine' and drift up to the stars!
> > >
> > > VERY elegant.
> > >
> > > Nice idea!
> > >
> > > Ben
>
> ------------------------------------------------------------------------
> -- Easily schedule meetings and events using the group calendar!
> -- http://www.egroups.com/cal?listname=alt-beam&m=1
Home