What about just the force on a vane placed in the airstream? RC models
almost never go above 1500 ft AGL in normal usage so pressure differences
would be small. I once saw an article on doing this very thing for
ultralights. It was in one of the free electronics magazines (but I can't
remember which :( I think it may have been the one that Bob Pease has a
column in.

Sean

At 11:45 AM 5/5/99 +1000, you wrote:
>At 21:13 4/05/99 -0400, you wrote:
>>how about measuring different
>>
>>glue 2 thermistors to 2 resistors
>>put the two resistors in series on a constant current source (constant
>>output heater)
>>put the one pair in the airflow
>>the other pair inside the plane
>>
>>measure resistance of both thermistors
>>the heatloss from airspeed should be a good indication of airspeed
>>(needs small mass so reaction speed is sufficient)
>>use  the pair inside the plane to compensate for air temperature
>>use a 2 dimensional lookup table for windspeed
>>
>>Peter
>
><SNIP>
>Do you think that it will work well at temperatures around -45C? :-) I
>guess that an altimeter would also be required, or another set of
>thermistors outside to measure air temp.
>
>Perhaps we should look into rocket control, as there are some methods of
>placing holes in the body, and measuring and calculating the disturbance to
>airflow-> speed and direction etc. Dunno much about it but. I guess that it
>would take more than a PIC to do the complex calculations.
>
>Dennis
>
|
| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
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