[simpits-tech] Zero point on a two needle altimeter
Chris Brace
simpits-tech@simpits.org
Sat, 26 Oct 2002 22:22:25 +1300
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Excellent idea. I particularly like this. One thing that springs to mind
though, your design means that when the ALT disks gets to 10000ft the
stepper will think its a 0 again. You will need to also design some way
to show the third pointer for the 10K increment. I guess I'd cheat at
that point and use a phidget LED to show the current ALT, but a third
disk could be done.
=20
I have been thinking of using a long bolt (say 2" or 3" ) with a nut
that travelled up and down the thread as the stepper rotatesmoved. The
nut would hold one half of a mechanical contact that would have a upper
and lower connection. this way the stepper would know when its at the
very top or very buttom of its travel. Now this will limit the steppers
total travel, but is does solve the idea of feedback for the likes of
ALT.=20
=20
Chris
-----Original Message-----
From: simpits-tech-admin@simpits.org
[mailto:simpits-tech-admin@simpits.org] On Behalf Of Johan Nauwelaertz
de Ag=E9
Sent: Saturday, October 26, 2002 9:14 PM
To: simpits-tech@simpits.org
Subject: [simpits-tech] Zero point on a two needle altimeter
Maybe a way to feedback a stepper in a 2 needle altimeter.
=20
I'm planning to use two disks, each with a hole aligned with the needle.
When both needles are at 0 position, the photo interuptor get signal
through the holes in disk. A counter will also help to reset altimeter
as fast as possible, i.e. If counter is more than 5000, continue to
count upwards to 10000, if less than 5000, reward to 0,
=20
Any thoughts?
=20
=20
Johan Nauwelaertz de Ag=E9
Sweden
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=20
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<DIV><SPAN class=3D016151609-26102002><FONT face=3DArial color=3D#0000ff =
size=3D2>Excellent idea. I particularly like this. One thing that =
springs to mind=20
though, your design means that when the ALT disks gets to =
10000ft the=20
stepper will think its a 0 again. You will need to also design some way =
to show=20
the third pointer for the 10K increment. I guess I'd cheat at that point =
and use=20
a phidget LED to show the current ALT, but a third disk could be=20
done.</FONT></SPAN></DIV>
<DIV><SPAN class=3D016151609-26102002><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D016151609-26102002><FONT face=3DArial color=3D#0000ff =
size=3D2>I have=20
been thinking of using a long bolt (say 2" or 3" ) with a nut that =
travelled up=20
and down the thread as the stepper rotatesmoved. The nut would hold one =
half of=20
a mechanical contact that would have a upper and lower connection. this =
way the=20
stepper would know when its at the very top or very buttom of its =
travel.=20
Now this will </FONT></SPAN><SPAN class=3D016151609-26102002><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>limit the steppers total travel, but is does =
solve the idea=20
of feedback for the likes of ALT. </FONT></SPAN></DIV>
<DIV><SPAN class=3D016151609-26102002><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D016151609-26102002><FONT face=3DArial color=3D#0000ff =
size=3D2>Chris</FONT></SPAN></DIV>
<BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV class=3DOutlookMessageHeader lang=3Den-us dir=3Dltr =
align=3Dleft><FONT=20
face=3DTahoma size=3D2>-----Original Message-----<BR><B>From:</B>=20
simpits-tech-admin@simpits.org [mailto:simpits-tech-admin@simpits.org] =
<B>On=20
Behalf Of </B>Johan Nauwelaertz de Ag=E9<BR><B>Sent:</B> Saturday, =
October 26,=20
2002 9:14 PM<BR><B>To:</B> simpits-tech@simpits.org<BR><B>Subject:</B> =
[simpits-tech] Zero point on a two needle =
altimeter<BR><BR></FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Maybe a way to feedback a stepper in =
a 2 needle=20
altimeter.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I'm planning to use two disks, each =
with a hole=20
aligned with the needle. When both needles are at 0 position, the =
photo=20
interuptor get signal through the holes in disk. A counter will also =
help to=20
reset altimeter as fast as possible, i.e. If counter is more than =
5000,=20
continue to count upwards to 10000, if less than 5000, reward to=20
0,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Any thoughts?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Johan Nauwelaertz de =
Ag=E9</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Sweden</FONT></DIV><BR>
<P><FONT size=3D2>---<BR>Incoming mail is certified Virus =
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