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?
You need to be a member of diydrones to add comments!
Replies
Don't forget, heat sink also. I'm sure you could still come in under 4LBS.
Watch you amp draw. Usually Voltage Drop will become your enemy at rated ampacity over large distances.
Yes forgot to mention the heatsink. I guess in case of something in air I can use something less than recommended and save some precious grams.
voltage drop can be handled. I can actually ramp up to 270V at ground station. If I remember correctly the supply can handle that. That way at highest current draw also I will probably be around 250V at max amps.
Why worry about the volt drop, the 3% I saw earlier does not matter in any way. the volt drop does not limit the distance. This is only relevant for a home or industrial installation
If you start at 240v from your supply and this drops to 220 at the copter it will still work.
As long as the ampacity of the wire will carry the current then dont worry, you can exceed the ampacity if you wish it will just get warmer. the total losses will actually reduce as the resistance increases.
http://www.rcgroups.com/forums/showthread.php?t=2070337
I wonder if something like this could be made to work:
http://www.digikey.ca/product-search/en?pv1120=1678&FV=fff40009...
110-220V input. 19V DC output, 12A, 1kg. Could it be de-cased and add a cooling fan, how much could it put out? At 240W, it's only 2A transmission on the 110V line.
Another idea, is you could use just an AC/AC transformer to step-down, and then a rectifier bridge to turn it to DC. Something like this:
http://www.digikey.ca/product-detail/en/A41-175-36/595-1302-ND/953172
But I'm surprised it's a whopping 5lbs! And only puts out 10A? That doesn't look very viable. Can you push these things beyond the ratings? Or am I missing something here?
Is it better to do the rectification at High Voltage, and then use a switching DC/DC regulator to step-down to your target DC voltage?
It is better to step down the A/C first. When you use a D/C regulator the wasted energy is dissipated as heat. That much heat would induce thermal runaway on other components.
220v is still quite low to send over thin wires. Even if you take a 1200W quad, which is just about minimum power to carry a power supply and camera, the current at 220V comes out ot be about 6A. 6A wire will be quite thick. The kind of wires that are being used I wouldn't be surprised if they are sending more than 600V.
But then the problem is it is very difficult to find supplies that take more than 220V AC or DC and output 12-24v dc.
I am not sure how difficult it will be to modify supplies that are rated at 220V AC to take higher voltages.
220V supplies are plenty and cheap
http://www.aliexpress.com/item/1200W-24V-110V-input-Single-Output-S...
and after removing there housing and extra moutings they will be less than 2kgs.
Such a funny concept in the arena of warfare... one pair of scissors...
I saw this company at the AUVSI Show this may. Hoverfly has a tethered drone they are selling for about $15,000.00 They are using a transformer on the ground that steps up the voltage, and then another step down on board the drone. Their tethering system also sent commands to the drone from a joystick on the ground, through the cable and to the drone.
http://www.hoverflytech.com/all-products-2/
I would still be interested to know "How high is the voltage". Though Hoverfly's tether looks much thicker than cyphy's tether. So I am guessing they settled for more off the self power supplies in the category of 220v or so.
In case of cyphy, it looks everything custom made even the tether. I don't have such resources at my hand. Such thin wire's will have to have very high dielectric strength sleeve material to be safe.
-
1
-
2
-
3
of 3 Next