brianr@tekig4.TEK.COM (Brian Rhodefer) (12/06/88)
The suggestion to use two matched thermistors in a bridge is quite good. I don't know if the following would be any better, but it might be more easily calibrated: Transmit an ultrasonic tone burst from one end of the aircraft, and pick it up at the other. The transit time for the pulse will be a function of the component of the airspeed along the line between the transmitter & receiver. Suggestively, Brian Rhodefer ...!tektronix!tekig4!brianr
waters@dover.uucp (Mike Waters) (12/10/88)
For the sake of (more) argument, the speed which intersts you (me?)
the most is surely the stall speed. Especially during landing.
How about two small flaps on the top/bottom of a wing which are
held in place by the normal airflow, but deflect in the turbulance
present in a stall. THere are several similar systems in use in
full size aircraft I believe, but haven't located details.
Another possibility is the integrated pressure sensors using IC
technology to sense the difference between top pressure and
bottom pressure might work.
Why differential? So it wont sound when the plane is sitting on the ground!
As for a stall signal, a loud audio tone (sonalert ?) would do nicely
for landings.
Another possibility is to put a low power AM transmitter on board, 1
transistor operating in the AM broadcast band. THe FM band is close
enough to R/C freqs. to be a little chancy. A fancier system would be
one of the cheaper wireless mic.s sold as toys, some of them are in
the AM broadcast band.
Any other ideas?
--
Mike Waters (for your EDIFication) *
Motorola CAD Group * Witty remark goes *HERE*
Mesa, AZ ...!sun!sunburn!dover!waters *
OR moto@cad.Berkley.EDU *ln63fee@sdcc13.ucsd.EDU (Dennis Lou) (12/12/88)
In article <592@dover.uucp> waters@dover.UUCP (Mike Waters) writes: >Another possibility is to put a low power AM transmitter on board, 1 >transistor operating in the AM broadcast band. THe FM band is close >enough to R/C freqs. to be a little chancy. A fancier system would be >one of the cheaper wireless mic.s sold as toys, some of them are in >the AM broadcast band. An interesting trick with this setup would be to fly over the parking lot and listen to all the cars with R/C activated alarms sound. "Where'd it go, I lost it in the sun." BEEP BEEP BEEP EEE RRR "There it is over the parking lot!" -- Dennis Lou ln63fee@sdcc13.ucsd.edu [backbone]!ucsd!sdcc13!ln63fee sdcc13 is also called issci2 "Tommorow is the derivative of today and yesterday is the integral."
tswift@well.UUCP (Theodore John Swift) (12/13/88)
[suggestion of using AM broadcast band for RC telemetry]
I'd like to know for sure, but I think there are some FCC technicalities about
remotely operated transitters: You are usually limited to "ground based"
operation. I believe this is true for the 27 MHz CB freqs at least. Any
FCC nit-pick trivia experts on line?
--
Ted Swift "Why is there a watermelon there?"
{hplabs,lll-crg/lcc, pacbell} "I'll explain later"
!well!tswift - from "Buckaroo Banzaii"waters@dover.uucp (Mike Waters) (12/15/88)
In article <7920@well.UUCP{ tswift@well.UUCP (Theodore John Swift) writes:
{
{[suggestion of using AM broadcast band for RC telemetry]
{
{I'd like to know for sure, but I think there are some FCC technicalities about
{remotely operated transitters: You are usually limited to "ground based"
{operation. I believe this is true for the 27 MHz CB freqs at least. Any
{FCC nit-pick trivia experts on line?
{--
{Ted Swift "Why is there a watermelon there?"
{{hplabs,lll-crg/lcc, pacbell} "I'll explain later"
{ !well!tswift - from "Buckaroo Banzaii"
I don't know the "chapter and verse", but such things as "wireless mics"
are not defined as "transmitters" provided they fall in certain limits
as to antenna size, power etc. Basically you can send just about anything
provided you don't modify the RF section or add a longer antenna etc.
You might look at the FCC regs, the part no. is listed on any of the
"non-radiating" devices. DON'T expect a coherant/consistent ruling from
the FCC, they are not noted for good responses to such "minor" questions.
--
Mike Waters AA4MW/7 *
Motorola CAD Group * Witty remark goes *HERE*
Mesa, AZ ...!sun!sunburn!dover!waters *
OR moto@cad.Berkley.EDU *