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Fly while powered by cable

nanakuma

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My goal is to fly Tello powered by a cable.
So I modified the original battery so that it can be powered by an external power source.
And I succeeded in connecting to WiFi while supplying power from an external power supply.
However, I tried to take off using the application for Tello, Tello did not take off.
Specifically, immediately after taking off from the app, the propellers rotate for a few seconds, and Tello's power is turned off.
What could be the cause of this and any advice on how to resolve this?
Also, is there a way to fly Tello while powered by an external power supply?
 
Have you seen power lines? You might know that the voltage on these is in thousands of volts. This is due to the same issue you're facing.

To have a cable of acceptable weight, you'd need to have step-up and step-down converter. Fortunately the buck converters are typically smaller and mounting it on the drone should be doable.
 
My goal is to fly Tello powered by a cable.
So I modified the original battery so that it can be powered by an external power source.
And I succeeded in connecting to WiFi while supplying power from an external power supply.
However, I tried to take off using the application for Tello, Tello did not take off.
Specifically, immediately after taking off from the app, the propellers rotate for a few seconds, and Tello's power is turned off.
What could be the cause of this and any advice on how to resolve this?
Also, is there a way to fly Tello while powered by an external power s
My goal is to fly Tello powered by a cable.
So I modified the original battery so that it can be powered by an external power source.
And I succeeded in connecting to WiFi while supplying power from an external power supply.
However, I tried to take off using the application for Tello, Tello did not take off.
Specifically, immediately after taking off from the app, the propellers rotate for a few seconds, and Tello's power is turned off.
What could be the cause of this and any advice on how to resolve this?
Also, is there a way to fly Tello while powered by an external power supply?
probably written in the software not to take off when it thinks it's charging.
The rotation of propellers you witnessed might be signaling software work in progress???
rewriting code could solve this obviously. Tello is an educational and open source for that very purpose, so you could fix that encode writing. look up TELLO EDU and Tello Robo master
before doing this, be aware that the Tello only weighs 80 g and I have done extensive experiments to see how much lighting I could add to many tellos in order to be able to navigate steadily in the dark.
strong motors for such a small drone but your problem is going to be in finding a cord that it can lift. What micro USB cable do you have in mind? And how long/how high do you expect Tello to be able to fly while connected, lifting the extra weight ?"from how long the chord is"?
you will need to modify a cable or strip it down to decrease weight, and even then, that will be challenging.
if you succeed at finding one light weight enough,....
you will have to navigate the cord to keep it below the propellers when descending, to keep it from tangle in propellers.

This however is most definitely worth working on.
just imagine the usefulness of such a set up?
emergency responders and militaries have corded drones that attache to automobiles that carry them.
for you to be able to make that on a much smaller micro, scale, would be impressive in its own right.
you'll still need more than one tello as motors will burn up at some point. keep the corded Tellos on rotation if you do succeed.
I wish you much luck
and
patience!
The weight Will need to be suspended from the center of the craft. Small rig from the charging port to the center underneath or possibly using a protective cage like in this picture enclosed. Extremely lightweight and works very very well,( also allows for rollover if landing upside down!!!)image.jpg
I would love to hear how you're doing with it ,as I would be happy to give advice if you need any help.
good luck keep me posted!
 
Last edited:
Have you seen power lines? You might know that the voltage on these is in thousands of volts. This is due to the same issue you're facing.

To have a cable of acceptable weight, you'd need to have step-up and step-down converter. Fortunately the buck converters are typically smaller and mounting it on the drone should be doable.
The corded Tello would be wonderful.
what type of cable "of acceptable wait are you referring"? I'm very interested!
 
Have you seen power lines? You might know that the voltage on these is in thousands of volts. This is due to the same issue you're facing.

To have a cable of acceptable weight, you'd need to have step-up and step-down converter. Fortunately the buck converters are typically smaller and mounting it on the drone should be doable.
Thank you for your comment.
I was so focused on the current that I didn't consider the voltage drop due to the length of the cable.
By changing the cable length to reduce the voltage drop, I succeeded in flying Tello while supplying power with the cable.
A compact step-down converter that can be installed in Tello will be considered.

I'm really thankful to you.
 
The corded Tello would be wonderful.
what type of cable "of acceptable wait are you referring"? I'm very interested!
Thank you for your comment.
I use Tello in current, and plan to consider using Tello EDU or Tello Robo master in the future.
(I didn't know Tello Robo master.)
In that case, a more detailed understanding of the software is required.

Thank you for your advice.
 
what type of cable "of acceptable wait are you referring"?
acceptable weight

If you decrease current, you can use a cable with thinner wires. Copper weights a lot.
This is what I was referring to.
 
Anyone knows the maximum Power consumption of tello?
If you consider that flying time is specified to be 13 minutes and battery capacity is 1300mAh, you will get more or less 6A current, at 3.85V that makes roughly 22W average. Peak power in my opinion can be about twice, so around 50W.

This makes it clear why lifting a cable of any useful length is impractical. Unless you add a buck converter of course, but a 50W buck converter has its weight. I suspect that your idea is not feasible...
 
This makes it clear why lifting a cable of any useful length is impractical. Unless you add a buck converter of course, but a 50W buck converter has its weight. I suspect that your idea is not feasible...
Thats why also tethered drones or (larger) vehicles with fuel cells usually still have a small battery on board to cover peaks like that.
Nevertheless I agree with you that Tello is way too inefficient in order to fly tethered.
 
Tethered you should bypass the battery really. But then you need to give enough voltage and amps to power the device. LiPo batteries have a high discharge rate - this is probably where you are falling down. Most USB chargers are low amps but a LiPo can do stupid discharge. I used to own my own RC company and got a LiPo developed that dumped 40A.
 
Thank you for your comment.
I was so focused on the current that I didn't consider the voltage drop due to the length of the cable.
By changing the cable length to reduce the voltage drop, I succeeded in flying Tello while supplying power with the cable.
A compact step-down converter that can be installed in Tello will be considered.

I'm really thankful to you.

Hello. I'm also experimenting with wired power supply, but even with a cable of about 1 meter,
I can't achieve takeoff. Could you please tell me what kind of power source you are using?
I'm using Kikusui's PWR-401L.
 
You should give some more infos:
  • Did you use a buck converter?
  • Wich voltage did you use?
  • Which type of wires (cross section) did you use?
  • Did you use the board from the original battery? (it's not only about + and - )
  • Did it work with shorter cables?
My guess is, that a capacitor (e.g. 470 µF) on drone side will be required (similar to the situation where you use ESCs wit longer power lines). May be, also two small super caps in series could help to reduce voltage drops at peak currents.

Otherwise you should try with high voltage and a buck converter, but as discussed already: Buck converters for this amount of power (at least 20W / 5A) continuesly are heavy as well.
 
: Buck converters for this amount of power (at least 20W / 5A) continuesly are heavy as well.
True, if you want to keep to spec. Ie this one:
1701526228730.png
43mm * 21mm * 14mm, weight - my estimation would be 25g
(found on Aliexpress, type "Adjustable DC LM2596 Buck module")

But there are cheaper things to test. These are unlikely to keep to the advertised amperage for long, but may be good enough to work, with an additional big cap.
1701526488483.png
Input: 5-20V, but this chip has also a variant with 32V input. Weight 5.7g.
(found on Aliexpress, type "mini560 Buck DC module")

The 2nd one can probably be adjusted by soldering different RC elements - chip datasheet would explain details. If not - 5V can be used with 0.7V diode.
 
But that diode also would have to be pretty "fat".
There are SMD 5A diodes, so the cap would probably still be more noticeable.

If the capabilities of the smaller board turn out to be a lie, then two such boards could be added - would still weigh less than one larger. Then the diodes would also help in merging outputs (though most likely there would be no issue with merging the modules directly).
 
You should give some more infos:
  • Did you use a buck converter?
  • Wich voltage did you use?
  • Which type of wires (cross section) did you use?
  • Did you use the board from the original battery? (it's not only about + and - )
  • Did it work with shorter cables?
My guess is, that a capacitor (e.g. 470 µF) on drone side will be required (similar to the situation where you use ESCs wit longer power lines). May be, also two small super caps in series could help to reduce voltage drops at peak currents.

Otherwise you should try with high voltage and a buck converter, but as discussed already: Buck converters for this amount of power (at least 20W / 5A) continuesly are heavy as well.
・I used the buck converter available at the following URL: https://ja.aliexpress.com/item/1005...750157!sea!JP!0!AB&curPageLogUid=wwsG52UchtdX.

・The output from the power supply is 12V, and the input voltage to the Tello is 4.3V.

・I used wires with an outer diameter of 0.75mm(AWG22).

・I disassembled the Tello's battery and soldered the wires from the converter to the terminals where the LiPo battery was originally soldered.

・I tried using a cable about 1 meter in length, but it did not work. I have not yet tried with shorter lengths.

I would like to continue experimenting by attaching capacitors or trying a different converter.

Thank you.
 
True, if you want to keep to spec. Ie this one:
View attachment 7188
43mm * 21mm * 14mm, weight - my estimation would be 25g
(found on Aliexpress, type "Adjustable DC LM2596 Buck module")

But there are cheaper things to test. These are unlikely to keep to the advertised amperage for long, but may be good enough to work, with an additional big cap.
View attachment 7189
Input: 5-20V, but this chip has also a variant with 32V input. Weight 5.7g.
(found on Aliexpress, type "mini560 Buck DC module")

The 2nd one can probably be adjusted by soldering different RC elements - chip datasheet would explain details. If not - 5V can be used with 0.7V diode.
Thank you for the information. I would like to try changing the buck converter.
 

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