Blew up the motor driver

[rufusmccoot]

Edit for those who come after me: If the IC on the motor driver pops and leaves a crater on it, you either forgot or didn't know to change the voltage on your voltage regulator (LM2596). The schematic clearly shows it outputting 3.3 volts but I don't know what I'm doing and didn't realize that was "hey dummy, set this thing to 3.3v" instead of "fun fact you'll get 3.3v here". I think it's perfectly reasonable for DavidBertet to make the assumption we would know it, so definitely my issue.

I'm using a 20v Worx battery so was shoving 20v into the motor driver.

If you're an idiot like me:

1) Unplug all the wires to your regulator 2) Plug a 9v battery into the input side 3) Hook up a volt meter to the output side 4) Turn the screw on the blue thing until you get 3.3v. I had to turn like 10 full rotations in either direction until it started changing my voltage so don't be shy.

These don't seem to work proportionally, so changing from 9v in to 18v or 20v in still results in 3.3v out. I tested this with 2 two 9v batteries to be sure.

Original post follows for context but I imagine zero to three people will ever need this edit and certainly zero people will ever need to read the original post that follows.

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I've got a new motor driver coming tomorrow because I blew mine up. I connected all the parts per schematic, reasonably sure I did it right, and I installed the code on the esp board, made sure web UI came up so that seemed good.

I tested with the original 6 volt battery first and the 7 segment display showed 6 volts. Cool. Swapped to my 20V Worx battery and about 2 seconds later heard a pop and the magic smoke came out of the IC on my motor driver. Didn't get a chance to press the throttle. 30A fuse didn't trip but you can imagine Dad's reflexes on the power button for a swift shutdown. I'm sure it's the IC there because, well, it exploded and I can see it.

I'll hack my way through this I'm sure but was just wondering if anyone had any ideas. Figured maybe someone can learn from my experience here in the future.

Great project. Neighborhood kids are cheering me on even.

[DavidBertet]

😳

I had to replace one. But after long hours of driving, and it just silently died because it got really hot. It has a temperature protection, so sometime it was tripping and I had to restart the car. One day it never came back... I put some thermal paste behind the heatsink, which helped a lot.

Blowing up the IC within few seconds is a whole different story however... no sure what can cause that. Triple check you don't have a short before to put the new one. It might have survived getting 6V instead of the 3.3/5, but not 20

Great project. Neighborhood kids are cheering me on even.

😍

[derekclawson]

I am also running into issues with the motor driver. I have 2 12v motors that I'm having it drive in parallel... The moment my kid hits any kind of hill, the motor driver shuts off and will do nothing until I power cycle everything. Going to try and run 2 motor controllers in parallel. (one for each motor) Is there something else I should try?

[derekclawson]

I've got a new motor driver coming tomorrow because I blew mine up. I connected all the parts per schematic, reasonably sure I did it right, and I installed the code on the esp board, made sure web UI came up so that seemed good.

I tested with the original 6 volt battery first and the 7 segment display showed 6 volts. Cool. Swapped to my 20V Worx battery and about 2 seconds later heard a pop and the magic smoke came out of the IC on my motor driver. Didn't get a chance to press the throttle. 30A fuse didn't trip but you can imagine Dad's reflexes on the power button for a swift shutdown. I'm sure it's the IC there because, well, it exploded and I can see it.

I'll hack my way through this I'm sure but was just wondering if anyone had any ideas. Figured maybe someone can learn from my experience here in the future.

Great project. Neighborhood kids are cheering me on even.

I'm running mine on 20v as well, nothing blew up, but I keep tripping some sort of protection on the hills. I'm going to try and run 2 motor drivers to see if that changes anything

[rufusmccoot]

Nice, thanks for the info and the confirmation that 20v in it of itself is not my issue. The issue could be the way I placed the electronics under the seat with no mounting or anything. I'm going to assume my issue was the "loose groceries in a bag" approach and try to come up with something better. I don't have a 3D printer so not quite sure yet. Of course I looked at everything and felt like it wasn't going to short out during a test, but this seems the most likely culprit currently.

I'll follow up here too so that future people can benefit.

I'm not sure if I need to do some tuning, like looking through the code and/or tuning a screw I see on one of the boards to dial input/output voltages or something. I might take a look at that too.

[derekclawson]

Nice, thanks for the info and the confirmation that 20v in it of itself is not my issue. The issue could be the way I placed the electronics under the seat with no mounting or anything. I'm going to assume my issue was the "loose groceries in a bag" approach and try to come up with something better. I don't have a 3D printer so not quite sure yet. Of course I looked at everything and felt like it wasn't going to short out during a test, but this seems the most likely culprit currently.

I'll follow up here too so that future people can benefit.

I'm not sure if I need to do some tuning, like looking through the code and/or tuning a screw I see on one of the boards to dial input/output voltages or something. I might take a look at that too.

@rufusmccoot I think there are some quality control issues with these IBT_2 motor drivers... I've been reading a bunch of forums that have weird issues that are fixed with a replacement driver.

[rufusmccoot]

The exact same thing happened with my second attempt. Everything is mounted cleanly now so I know I didn't short two boards together. The IC on the IBT_2 pops and a crater remains!

Unrelated issue I think, I can't get the foot pedal to show any resistance readings across any two pins, which is how it came on arrival. Maybe that's related? I'm also just assuming the green wire from the foot pedal's green, black, red is the orange one in the schematic here.

Or, I haven't played with the screw on my voltage regulator at all and I see we want 3.3v out. No idea how to get that screw to the right setting but I'll fiddle with that too. Will report back when more hardware comes in the mail.

[rufusmccoot]

It was the voltage regulator. I'm an idiot. Edited original post with findings.