xrayjb2
Posts: 19
Joined: 1/19/2007
From: Tucson,
AZ, USA
Status: offline
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jkantiques,
Wow, that is cool! I think you DESERVE UFO calls for that one! Alas, I have nothing to post...Not yet.
I've continued my work with the cold cathodes. They do not draw the 10 mA as advertised. It is more on the order of 600 mA. In addition, connecting it to the standard X-Pro battery (16 volts when fully charged), ramps up the current even more, and in about 5 minutes the inverters become dangerously hot. The tubes glow amazingly bright, but it is too bright, as the heat glue holding them in place melted. I have had success adding two 10 watt, 10 ohm resistors in parallel for total resistance of 5 ohms. They get hot, but not hot enough to melt anything (but hot enough to scald the skin in 2 seconds). With resistors in place, the inverters barely get warm, and the lights are still overdriven a bit, but not enough to cause inverter heat issues (though ultimately I'm sure it will shorten lifespan). The problem is the extra current draw, which is not reduced but is resisted out as heat. I am probably pulling 8.5 watts of power (resistors and all), to power these four tubes by the flyer battery. That, plus the 1/2 pound weight, is going to shorten runtime to, I'm guessing around 11 minutes. The alternative is the smallest 12 volt pack available, which is a single 9 volt (lithium) and a single 123a batttery, wired in series. I conducted a runtime experiment with four 123a's in series (total voltage 12, total mah, 1300), and they ran the tubes pretty bright for 30 minutes, then gradually dimmed until a total runtime of 1 hour, 45 minutes, at which time the tubes stopped "filling" the entire length with light, and that is when I stopped the experiment.
A lithium 9 volt and a 123a together is lighter than four 123 a's, and weighs about 1.8 ounces, so with these on board, total payload is about 9 ounces, and runtime should be about 18 minutes. Of course, I have an additional 32 LED circular strobe array, which requires an additional 9 volt (1.2 ounces). Grand total of the payload of lights, with separate battery packs, is 11 ounces.
There is another option for wiring these lights to the main battery pack; adding a DC/DC converter, and scaling down the voltage to the lights from 16 to 12 volts. That adds more expense, more weight, and I really don't even know how to do that (I'm a doctor, not an electrician).
My rebuilt flyer shipped out Thursday, and will probably arrive by Tuesday. No matter how short the runtime, photos will be coming, as promised. I am going to try initially attaching the lights hooked to battery with red hot resistor sinked to an aluminum riser. If the runtime is indeed only ten minutes, I am probably going to permanently revert to the 9v 3v setup.
John
John
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All Forums >> RC Helicopters >> Draganfly Innovations Products >> RE: Draganflyer Navigation Lighting Systems 
RE: Draganflyer Navigation Lighting Systems - 
I hope I'm tall enough to ride that ride. 
