Building an electronic Angle of Attack indicator
On May 13, 6:21*pm, Dan wrote:
wrote:
I learned a great deal from this thread, especially all the references
cited.
Thanks to everyone for contributing.
I think I may build the Jeff Shultz circuit,
with 8 segments if bar LED, plus a red and yellow bar-like LED.
However, I am not quite sure Shulz's logic of the lights is what I
want.
The display logic that makes sense to me is this:
in cruise many green LED are lit *(could be 5-8), All greens
at this point, no yellow or red lit. *These progressively
go out as the nose is lifted. *Then the yellow comes on...with no
greens lit
then the red comes on. *I guess the yellow can stay on when the red is
lit.
might want to make the red flash.
a job for a PIC?
-Jeff
* * If you make your own bar graph you can use a flashing red LED.
Either that or use a yellow bar graph with separate flashing red LED. I
think Radio Shaft carries them. I'd wire the yellow such that they
remain lit as they climb until all are lit just before red illuminates.
* *There are commercial systems available to the homebuilder. Look at
their displays for ideas. If you find an array you like it shouldn't be
too difficult to make one similar.
* *I have the feeling no two people will agree on what's best.
Dan, U.S. Air Force, retired
The interest for me is a sailplane installation where AOA is a
performance issue in addition to a safety issue.
My glider can be flown at 1000 pounds up to 1433 pounds gross weight
and spends a lot of time in 2G turns thermalling. The AOA for minimum
sink is always the same but the airspeed at which that happens changes
a lot. The same thing with best L/D.
A very 'slippery' glider takes a while for the airspeed to settle down
after a pitch change. Flying to an exact AOA would be easier than
chasing airspeed.
An AOA indicator that shows minimum sink and maximum L/D as well as
stall would be quite useful.
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