Alt-BEAM Archive
Message #11132
To: beam@sgiblab.sgi.com
From: BUDSCOTT@aol.com
Date: Tue, 29 Feb 2000 17:31:06 EST
Subject: [alt-beam] Re: Diskette Drives/camera parts
your kiddin me, they use those in cameras! i bought a couple slot car style
motors from MPJA that had permanant magnets (thought it might make it more
efficient) that were .50 cents they also ended up drawing over 100 mA or so i
recall.
11133 Tue, 29 Feb 2000 17:33:05 -0500 [alt-beam] Re: mini walker beam@sgiblab.sgi.com "Sathe Dilip"
Richard Piotter wrote:
>
> As mentioned earlier, the distance the magnet travels is 1/4 inch.
>
> Would it be wiser to use a pair of coils, one on either side of the
> magnet? If so, what'd be the recomended wiring, series or parallel.
>
That would certainly help. But if you want try with a single coil
first. If you find that the force is not enough, add the second one.
Series or parallel both will work & will have their pluses & minuses.
Assuming the coils are reasonably identical, connecting them in parallel
will double the current requirements. You will have to use a fatter
capacitor & more capable switching devices (transistor/IC). Using them
in series will make them both carry the same amount of current but
unless you have a higher voltage to drive them, the individual pull/push
will be somewhat lower.
I think connecting them in series will also flatten the initial kick due
to increased series inductance.
Now I have another question. Are you planning on using the sticking
force between the magnet & core to hold the legs during their idle cycle
Or planning to use a steady current flowing through the magnets to do
this/augment this? Your answer will have bearing on the coil design.
You want little to no load on your source when a leg is not moving =
high coil resistance = lower kick & holding power. If you design for
more pull & kick, the steady state current drawn (which is only limited
by the coil resistance) goes up. If you could make it work with only
the (passive) sticking force, that would be ideal.
Dilip
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The early bird may get the worm, but the second mouse gets the cheese.
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11134 Tue, 29 Feb 2000 17:32:49 EST [alt-beam] Re: shack caps beam@sgiblab.sgi.com BUDSCOTT@aol.com i've seen some solar panels from the shack, don't put out much voltage, but i
was thinkin of buyin a couple and puttin in a series, do any of you guys know
about these, and how good they work, i found them in the very back of a
shelf, they were kinda hidden away, not a match for a sunceram, but would it
be wortha try?
-Spencer
11135 Tue, 29 Feb 2000 17:48:13 -0500 [alt-beam] Re: mini walker Rob Rix > No! It looks like (gasp) an I MAC!
No, it's one of the Blue and White G3 Macs, the Yosemite towers, replaced
recently by the blazing G4s.
My comment had to do with one side of his mouse being a different colour
than the other.
Peace!
-- Rob
Don't take a walk, climb a tree =8B an ancient truism, invented last week.
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