Issue with TCB rebooting with certain actions

[Jib]

So I’ve found that when I do certain maneuvers that put a high load on the system, the TCB seems to reboot. Everything will stop moving all of a sudden, the sound stops, then the lights (brakes, headlight, machine gun) flicker, and then I am able to start normally again.

This mostly happens whenever I turn the turret very fast or change turret direction quickly. I have measured the amps for these sorts of maneuvers and it can get almost up to just below 4A. I have a 4A fuse between the ESC and the traverse motor, that is still intact.

The traverse ESC is not supplied any power from the TCB. The ESC receives 24v from the main line and the TCB receives 12v from the same main line.

Before, only the ground and signal were connected between the ESC and the TCB, at RC Output 3. Recently in order to trouble shoot something else, I connected the ESC to the PWM end of my RX, the same RX that is plugged into the TCB via SBUS. Again, only the signal and ground from the ESC are connected to the RX.

I have a sneaking suspicion that something similar is happening with the drive ESC. The drive ESC is supplied power from the TCB, but the motors are powered from the main line, and the controllers and motors are galvanically isolated. I have had instances where when the TCB reboots, the drive motors don’t work. I will hear the sound, but nothing happens. When I look at the error code the drive ESC is throwing it says “no valid signal at control outputs” I’m guessing this means it’s not getting a signal from the TCB. I will ask the maker of the drive ESC what might cause this, but it seems a lot of this has to do with the TCB resetting mid operation.

If you can shine some light on why any of this is happening, I would appreciate it.

Thanks!

PS I did look in the wiki under troubleshooting, but didn’t see anything relevant.

[tankme]

How close to the tank are you when this happens? I know with my QX7, if I'm too close to the tank I get disconnects where it will shutdown and then restart when I step away.

[Jib]

Fairly close, but it seems to be repeatable that this occurs whenever there is a large power draw by the traverse ESC. The TCB then appears to shut down and restart immediately without me moving around at all. I do have to “restart the engine” by flipping the switch assigned to that.

I am assuming it’s the TCB rebooting, but might this behavior happen if the RX is rebooting or disconnecting?

For what it’s worth, when my RX does get disconnected, I get a “receiver disconnected” sound from my TX, and I am not getting that in this case.

Also, this was not an issue when I was using the 24v ESC with the TK 8.1. Only became an issue when I switched to the TCB and a separate RX. I am using a Radiomaster ER8 and TX16S BTW.

Weird thing is, after first installing the new electronics, I took it down to the park and ran it pretty good and had no issues. A couple days later I’m showing it off to my friends and it started doing this. I’m wracking my brain trying to remember if I had changed anything between those two dates.

[Jib]

I think my issue might be with how my power converters are set up. I’m working with someone via email, will report back here when I have a solution

[LukeZ]

Hopefully you discover if there is a problem with your voltage converters, let us know. What you describe does sound like a reboot. I'm sure it's not very practical, but if you could find some way to see the TCB while you're doing these maneuvers you could tell by the behavior of the onboard red & green LEDs if a reboot happened.

[Jib]

The suggestion I’ve gotten right now, is to try to isolate the power for the reciever connected to the TCB, away from the TCB. So giving the RX its own power source.

I don’t quite understand the ideas is trying to get across to me. It seems like when I have a big power draw from traverse, it’s causing the TCB and/or RX to have an under voltage trip? But I think it has something to do with my power converters being arranged like this:

40v to 24v to 12v to 5v

And maybe they should be like this:

40v to 24v
40v to 12v
40v to 5v

He recommended plugging the RX into a little 5v receiver battery I have and just running ground and signal to the SBUS of the TCB. If that works, then it sounds like I should try getting a 40v to 5v for the RX. I also have a 40v to 12v I could try, that would be easier for me to implement than the 40v to 5v, so I might try that too.

I might have a way to view the TCB while jamming on the traverse motor, might give that a try too.

Will report back here with the results when I get the time.

[LukeZ]

Hi Jib, I definitely think that you should arrange your converters to each be powered directly from the battery, as you show in your second example, rather than stringing them together one downstream of the other. As it is, your 24 volt converter has to handle the current draw not only of its own 24 volt devices, but all the devices beneath it. It is likely that when the traverse motor exerts itself this is proving too much for the 24 volt converter, and all the downstream converters/devices begin to falter as well.

[Jib]

Yes and this was the concept that the other person I have been talking to (the maker of my traverse and drive ESCs) has tried to impress upon me. That when the current draw from the traverse ESC spikes, the 40v/24v converter suppresses the voltage to limit the current to protect itself, and in the process it causes everything else under it to go under voltage. But all of this happens so fast that the fuses don’t have a chance to melt before the converter “corrects” the current draw and the voltage is returned to normal, thus the under voltage reboot. Or at least that’s the theory of what’s going on.

I’m looking at seeing if just having the elevation ESC, traverse ESC, and amp under the 40v/24v 30A converter, and everything else under a 40v/12v 20A converter.

Due to the size of these converters it’s not really practical to have a converter for each of these items individually, but depending on how this goes I may have to. Or at least have the traverse ESC under its own converter.

[Jib]

So even after then change I’m still suffering from I’m guessing are voltage drops when the turret ESC spikes.

However it did seem better with the new configuration, like the TCB restarted, but everything else kept functioning normally UNTIL when I was driving around today at full speed up a hill with turret/barrel stabilization turned on, shooting the Airsoft cannon, then all of a sudden the power to everything completely cut.

I thought maybe I had blown a fuse, because even when I turned the model off and back on, it was like nothing was getting power at all.

Some I pushed it back home, took it apart to see, the fuses were fine and I tried to turn it on again and everything worked normally.

Does this ring any bells to anyone though? Like it wasn’t just a board reset, like there was no power to anything. And flipping the switch didn’t bring power back until I tried again maybe 20 minutes later?

[LukeZ]

Hi Jib, it sounds like you need to make some current measurements of your devices and figure out what component is drawing too much from one of your converters. I don't know why everything would have cut out for such a long time, but perhaps there is an overcurrent/overheat protection circuit somewhere in all your components that has tripped, and takes time to reset. Of course I'm only theorizing, but anyway, you need more information before you can figure out the cause and remedy.

In any event it sounds like this is more than a problem of the TCB browning-out, so perhaps you will get more responses if you can find a forum that deals either with your ESCs or converters...