Sorry dude, I was masturb... I mean I was doing some research and didn't see these posts.
I'd just go with some Ethernet. It's cheap, comes in big spools, is weatherproofed (relatively), relatively lightweight (~0.04lb/ft) and is made for data transmission. You can get Ethernet with stranded wires too if you need it more flexible, but it probably won't matter too much unless you're kinking it.
For power, buy some power-over-ethernet (PoE) adapters for power transmission and be done with it (well, after you convert the power too). I think you can get about 15W out of the lowest standard over 100m. You can then also send the data straight over the Ethernet and not have to worry about noise and crosstalk and all that shit which is such a pain to deal with. Another nice thing is that you can just connect to a 48V power source (like a battery) directly (though don't draw too much current).
Believe me, you don't want to waste your time debugging these signal and power lines. It sucks. It's the worst part of these projects. Buy more helium if you need more lift, but don't compromise on having a nice and easy standards-compliant system that you don't have to waste your artistic time fighting to get working.
You'll need to use some sort of circuit to drop the voltage down to usable levels, but at least you'll have the transmission part done. You can probably even use the splitters that come with those kits for that.
Are you sure that 100lbs is going to be enough for your anchor? Those balloons have a large cross-section, and wind loads are going to be strong. I did some calculations using
this site to calculate the force. Note I'm just translating what I found on the site; I'm not a wind load expert by any means:
Code: Select all
Wind Force = A × P × Cd
A = Projected area of the item
P = wind pressure
Cd = Shape/drag coefficient
A = pi * (6ft / 2)^2
P = 1/2 x p_a x U^2
p_a = mass of air. We'll use 1.165kg/m^3 on the playa from http://exchange.dnv.com:6389/dynaweb/offshore/rp-c205/@ebt-link;hf=0;ts=default;pt=11065?target=%25N%15_32496_START_RESTART_N%25#X
U = effective average wind velocity,
Cd = depends on the diameter and the "Reynolds Number" in table 5.3:
Re = D * U / Va
D = diameter = 6ft
U = as above
Va = kinematic viscosity of air at the elevation (we use 1.6e-5 from above)
So for a single balloon:
A = pi * (6ft / 2)^2
P = 0.5 * 1.165kg/m^3 * U^2
Cd = function of Re = 6ft * U / 1.6e-5
Since U will range from about 10mph to 40mph, Re will value out between 500,000 and 2,000,000. From the table 5.3, we'll use 0.15 for Cd
Force = 0.15 * (pi * (6ft)^2) x 0.5 * 1.165kg / m^3 * U^2
Some values for "standard fare" wind speeds out there:
Code: Select all
Force @ 10mph = ~ 5 N
Force @ 20mph = 18 N
Force @ 30mph = 41 N
Force @ 40mph = 73 N
Force @ 50mph = 114 N
Force @ 60mph = 165 N
Note that is per balloon. I don't know if there are shielding effects or how a group of balloons perform. You'll probably drag them in anyway if there are > 60mph winds.
Your 100lb weight exerts about 444 N of downforce. That's just downforce though. You'd probably need some guylines for the side-loads.