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Micro filament on Tethered UAV

Posted by Matt on March 23, 2014 at 2:01am

Cyphy has popped up again...

http://www.northeastdronenews.com/start-cyphy-works-developing-highly-disruptive-uas-technology/

What sort of technology is involved in getting 1000W through a filament thinner than headphone cord?

tech-microfilament-slider-01-w940h360.jpg

CyPhy-Works-UAS.jpg

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cyphy, tethered, uav, filament, micro

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Moderator

Bill Piedra September 4, 2014 at 10:22am

I wonder if CyPhy could be using something exotic like Tesla's single wire transmission. Maybe they figured out how to make it work. Something like this:

http://viesh.ru/pre/development-of-resonance-methods-of-electric-po...

Resonance methods of electric power transmission | ФГБНУ ФНАЦ ВИМ

Resonance methods of electric power transmission (Devoted to the memory of Nikola Tesla, /10 july 1856 7 january 1943/) D.S. Strebkov, Academy of
- Pritam Ghanghas > Bill Piedra September 4, 2014 at 12:07pm
  
  No they are not using any of that. They are supplying power over a 2 wire system. And they are definitely supplying High voltage and stepping it down in the quad. The questions are
  
  How High is the voltage?
  
  AC or DC?
  
  is their quad so light and efficient that they are managing with such thin wire and still keep the voltage with safe limits?
  - Pritam Ghanghas > Pritam Ghanghas September 4, 2014 at 12:12pm
    
    I am so interested in this because I am working on something like that that can go about 400ft with ground supply. Needs to stay there for longer periods.
    
    I am having hard time finding something so thin and capable as microfilament.
    
    secondly with heavier wire and powersupply weight, I need more power, that gives even more weight. Its a vicious cycle that only goes up. I have reached a configuration where my hover power is around 1600W despite using lot of carbon fibre for frame.
Pritam Ghanghas September 4, 2014 at 12:52am

I am wondering too. Carrying high voltage dc over such long wires and then using regulator on the drone will not be very efficient. The regulator itself will dissipate a lot of heat/power.

The other option of using high voltage AC and then having a power supply on board is equally challenging. Too much weight.

Both approaches also have the hazard of handling hight voltage in proximity to people.
Moderator

Dwgsparky March 23, 2014 at 4:36am

Hi voltage, good insulation. 500v. X 2Amp = 1000watt. It's nothing special. Now finding 500v esc /motors might b tricky!
- Pritam Ghanghas > Dwgsparky September 5, 2014 at 12:48pm
  
  Thinking more about it, I think they are definitely sending high voltage through the line but I don't think they are using it directly to power the drive system. There is some step down involved. At 1200W such a power supply will not be light for sure. So still puzzled.
- Matt > Dwgsparky March 23, 2014 at 1:06pm
  
  I would have thought it would be more than just fitting the maths to suit the cable diameter.
  Maybe something with ultra low resistance like superconducting wire.
  - Moderator
    
    Dwgsparky > Matt March 23, 2014 at 4:25pm
    
    Superconductors will be very difficult to achieve out in the open , The copper cable resistance increases as the cross section decreases and the the current capacity of the wire also decreases. By increasing the voltage you lower the current required for a load and more importantly lower the losses in the wire. That's why the power transmition wires out on the pylons are at 400kv or more. I still don't see the point of carrying the cable and reels up in copter