Howard's Flashing LED

[Steve Helmick]

Last night, I was thumbing through the Oct. 2012 issue of Model Aviation magazine, and came to the "Product Spotlight" feature. There are often interesting items discussed there, even though they are (of course) intended for R/C. The one that caught my eye was from "RAM", which the article explained stands for "Radio Controlled Models, Inc.", which struck me as pretty funny in itself.

Then, reading more, I discovered that the product was flashing LED lights. They work on individual LiPo button cells, so no wiring is required, and it said the three only weigh 5 grams, but even if it was per unit, that would be very tolerable. They are intended to be semi-scale navigation lights, so would be red, green and white. Suddenly, I had a strong urge to have one on the nose of my stunter, just like Howard's. Of course, mine has an OS .46VF in it, so unless I can figure out a way to have it tell me something, like how much time is left of my 8 minutes of fame, it would just be a status symbol. But that's not a bad thing...    Steve

[Tim Wescott]

Put the sensor from a helicopter governor on it, and do a bit of electronics, and it'll tell you whether or not your engine is running.

[Howard Rush]

That's silly.  He can see the smoke.

[Steve Helmick]

Now see, that wouldn't make any sense at all, Tim! Even at my age, I can hear that the engine is running! I'm not into technology for technology's sake. How about letting me know how much fuel is left? Any way to do that? I'd actually be open to a countdown timer. I might even consider putting the LED on the outside of the circle for the judges to enjoy...   Steve

[Rafael Gonzalez]

IN the old days the fuel gage was a capacitance measurement. As the fuel was used, the capacitance of the tank would decrease. In any tank attitude, the fuel  was always correct.
Try and build an adjustable capacitance measurement gage for the fuel size of the tank and when is at the setting, it will turn a bright LED on. You need to stay with the same fuel when calibrated.

[Tim Wescott]

IN the old days the fuel gage was a capacitance measurement. As the fuel was used, the capacitance of the tank would decrease. In any tank attitude, the fuel  was always correct.

Which old days, and what fuel tanks?  The automotive fuel-level senders that I know of (with the exception of the Model A Ford) all use variable resistance elements.

[Tim Wescott]

Now see, that wouldn't make any sense at all, Tim! Even at my age, I can hear that the engine is running! I'm not into technology for technology's sake. How about letting me know how much fuel is left? Any way to do that? I'd actually be open to a countdown timer. I might even consider putting the LED on the outside of the circle for the judges to enjoy...   Steve

Hey, you said you wanted it for a status symbol...

A countdown timer would be fairly easy.  A fuel gauge would be harder, with the hardest part being to figure out a decent way of making a fuel level sensor for a stunt plane.

[Steve Fitton]

It would cause much excitement if the light actually was hooked up to nothing, but under the light was a little stencil saying "stab aug"

[PJ Rowland]

A countdown timer would be a great idea..

[Rafael Gonzalez]

Which old days, and what fuel tanks? The automotive fuel-level senders that I know of (with the exception of the Model A Ford) all use variable resistance elements.

I apologize. I was referring to fuel tanks in aircraft. But, variable resistance is not variable capacitance. A float with a variable resistor attached to a lever is not a pair of rods in contact with the fuel at all times in any attitude. Remember the old AM radio tuners?
As the opposing plates increased their contact area with the air, the freq. was changed thereby tunning to the station. We could nave a circuit that detects the capacitance as the fuel gets lower or a variable freq. can be generated as the fuel changes. 

[Tim Wescott]

I understand the difference between capacitance and resistance.  I figured that you might mean aviation fuel senders (about which I know nothing).

Detecting a varying capacitance would certainly work.  I think it might be a challenge to figure out a sensor geometry that would get an accurate measurement as the fuel sloshed around, but having a small sensor around the fuel pickup would let you know when you were in the end game.

[Garf]

A capacitance detector requires AC to work.

[Tim Wescott]

A capacitance detector requires AC to work.

So?  Oscillators are easy to come by.

[Garf]

It does complicate the circuitry a little.

[Howard Rush]

In an electric airplane, you would have a good source of power, and you could build the fuel level detection into the timer program.  Oh, wait.  Never mind. 

[Don Hutchinson AMA5402]

Timers can be calibrated using the JCT Clock.

[Mark Scarborough]

It would cause much excitement if the light actually was hooked up to nothing, but under the light was a little stencil saying "stab aug"

LOL,, yeah I like this idea a LOT,, hmmm 

[Steve Helmick]

How's about adding a toggle switch, one direction being labled "OTS" and the other "Modern"?  Steve

[Brett Buck]

It would cause much excitement if the light actually was hooked up to nothing, but under the light was a little stencil saying "stab aug"

   Someday I will show you how my IR Signal jammer (that I took to the NATs the year Windy flew the Z-Tron controlled airplane) works. I never actually used it but I am sure it would have been effective.

     Brett

[Paul Smith]

I went to the annual Boxing Day indoor park flying session at the Pontiac Ultimate Soccer Arena.  The entire perimeter of the field was lined with RC flyers.  There must have been almost a 100 of 'em.  Several had various combinations of red, white, and green LED on their toys.  Considering the heavy traffic and dim lighting, it helped them find their own planes in the crowd.

In CL a line pull warning would be somthing to do.

Green for OK
White for slack.
Red for overstress.

Not exaclty necessary, but something to do with the toy.