Sometime last year we began tossing the idea around that we might be able to build a simple tethered power supply for small hobby drones.

At the time there were a dozen projects / companies around the world building tethered systems for multicopter drones. From CyPhy Works in the US with their super funky DARPA funded 5000volt system to the impressive Sky Sapience Israeli military monster that looks like it could lift the humvee it’s attached too.

Surely we could build a small system for a DJI Phantom?

Tethered Test Flight

It took us almost a year but we got it flying!

Stable flight with no issues for 30 minutes
50m Tether

Such an exciting moment.

This is a 300volt setup. But the clever bit is taking 300v and converting it down to the 15v the motors need, without adding too much weight. In fact our little converter weighs less than half of the battery we removed, giving us more than enough extra lift capacity for the cable.

It’s still very much a prototype but so exciting that it worked as we thought it would.

Works nicely on the F550 Hex too

Small problem with the DJI Phantom though

That was the goal, to make a tether work with the worlds most popular drone. Well we hit a small snag. Yes our weight and power requirements are perfect for it and yes we’re small enough to fit inside the battery bay… just one small detail…

DJI have started encrypting their battery signals… much like inkjet printers detect genuine ink or fake ink cartridges, DJI want us to only use their genuine batteries. That’s fair enough, you don’t want dodgy batteries bringing down your wonderful machine. But it is a bit of a pain for us… We’ll have to have a think about that one.

Catch you next time.

When ducks attack!