Oh another thought I had, you could couple it with a 2S50mAh lipo if you really wanted to save weight. That'd give you 8.4V on a full charge to set off the igniter which is reasonably close to 9V.

Paul.

Paul,

Harking back to the Altimeter, I reckon a flight timer would be very handy as well. Obviously the altimeter has a clock so it wouldn't be hard would it. My JR 2720 doesn't have one.

I have to say, that is one thing that really tests my love for JR at times, really I do like their gear but the disturbing lack of fundamental things like a count-down/up timer on the TX really gets me mad.

It is the only disappointment I have in the 2720. Apart from that I reckon it's a cracker!

You know what'd be good on JR's... a plugon clock/timer that works based on the PPM stream out of the trainer port... trouble is, plug that in and it probably shuts down the RF-transmitter The bad bit however is that as slick and nice as you might make an additional timer block, it still is an awkward accessory hanging off the TX, something to get knocked off/beaten-up, cause complications.

I was thinking that the altimeter/flight recorder would have a clock anyway solving the whole problem. I guess i should explain that my interest in timers is purely for curiosities sake. I would just like to know how long a flight lasted. I have no interest in the competiton slam dunk the circle on time stuff. More for highly scientific research in to flight duration

update

The pressure sensors have been sent - probably a week now before they land here.... then another two years before I use them

Paul.

hey paul ..

how about a v-tail mixer with rates that can be set independently from one another , they had one years ago , but it would set all rates the same and was hugeemongus ... a nano mixer would be cool for all those smalle wings ive got

cheers
doug

Doug,

Interesting idea, I did have one in development but things got canned when I ran into the clock-jitter problems with some of the equipment used to do the 'mixing'. I could probably look at the situation again and produce a unit to do the job, likewise a go-slow and compander, all were in demand until the jitter problem forced me to can production of them (nothing like having 300 units ready to go and then having to just trash them ).

Paul.

updates

The pressure sensors have arrived. They're still a little larger than I had anticipated but certainly not "insanely large". They're about the same footprint as the little microcontrollers I use on the BAC units but twice the height.

... now, to make good use of them

Paul.

I'm not sure I understand the need for another altimeter. We already have:

EagleTree
http://www.rc-electronics.org/
http://home.epix.net/~rcbrust/
http://www.magtechinc.net/SkyAssistant.htm
and other similar to those.

I'd like a servo current logger. Monitor servo current with a fairly fast sample rate, log the data and download to computer. Maybe also a realtime display option.

Ralph,

What I do have "in design" is a bench-top servo analysis tool that goes far beyond the usual "servo tester" unit.

This unit does the following;

* End point discovery
* Current logging
* Jitter/dead spot discovery
* Torque / current mapping
* Torque limits
* Performance/speed testing
* Linearity testing

It's a hefty device but the problem is that there's a lot of mechanical stuff involved in it and I can't find an easy way to manufacture those bits yet.

It also can consume a fair bit of power for the torque testing :|

Paul.

I can certainly see the use of a bench top servo tester, but I'll just wait until someone else tests the servos and read the data.

I'd like something small that I can put in a plane to monitor either total system current or servo current. Basically go between the rx and battery or rx and servo.

That way I'll know if my rx battery if big enough or if my BEC is up to snuff.

Should be pretty simple... sense resistor, amp, micro, memory, ttl level uart (off board RS-232 converter).

Depending on how your study with the boost converter and Spektrum radios goes, I'd like to see a charge controller and switch for thin film solar panels and 1S lipos (2S if such a controller exists).

Panels are cheap enough that 10-20$ worth is adequate for 150-300ma (Although alot of the ones I see aren't UV stabilized, or it costs more for stabilization).

A few grams for panels + whatever a charge controller. Thin film is thin enough (0.2mm) that you could place it towards the middle of the wing chord and not have an impact on airfoil, and you wouldn't need alot of surface area.

Combined with the low voltage alarm for extra assurance, and some switch to turn everything off.

Not having to charge during a contest would be cool.

Ralph,

Where this servo tester aims to be "more relevant" to general use is for diagnosing of possibly-dud servos, especially things like 1-tooth-missing events or pitted feedback pots etc.

Now as for the current meter, yes, it's moderately simple (you'd probably log amps and volts to give a better picture). Something like that would probably end up being about the size of the BAC-ESJ units but a bit thinner.

Paul.