How hard is it to kill a Tesla LDU encoder?
Posted: Sun Jun 04, 2023 8:58 pm
I have a Tesla LDU with a new OpenInverter board running the latest firmware. I'm doing low-voltage tests with two UB12350 12v scooter batteries. They're not super powerful, but they will turn the motor.
The problem is that the motor doesn't turn smoothly. I'm getting that jogging/cogging/clunking thing that implies the encoder wires are swapped. I've read through a lot of forum posts trying to figure out how to fix this.
I'm using the default inverter settings, except:
- udcmin is 0v
- udcsw is 15v
- potmin and potmax were adjusted for my throttle.
What I've done so far:
- Swapped the encoder wires. Same result.
- Unplugged the encoder entirely. Same result.
- Tried changing encmode to A, but that had no effect (I set it back to AB, which as I understand it is what Tesla motors should always be set to due to the quadrature encoder).
I then wanted to test the encoder itself. Since I don't have an oscilloscope to play with, I connected it to a logic analyzer. I powered the encoder directly with a 5v bench power supply. It was not connected to the OpenInverter board, which I used to spin the motor with a dedicated 12v power supply and the two 12v batteries. My motor didn't come with shafts, so it's difficult to spin it diff by hand; I'm assuming that you have to hold one side still while you turn the other side for the encoder to pulse. Having the OpenInverter board turn it seemed simpler.
Now, importantly, I screwed up my encoder test by mistakenly swapping the 5v and ground from my ben ch power supply to the encoder. I feel like this PROBABLY didn't kill the encoder, but I'm not entirely sure, mostly because I don't know how this particular encoder works (is it hall-based or optical or what) and how sensitive it is to reverse polarity. I feel like it's probably fine, but since I could never get anything out of it to begin with, I'm not entirely sure.
Mind you, it wasn't working before I reversed the polarity, so that's not the root cause of my problem.
So my questions are:
- How can I be sure the encoder works?
- Did I kill the encoder with reverse polarity?
- if I did, does anyone know the part number of the encoder so I can replace it?
- Is there a way to see the raw encoder values in the OpenInverter web interface? I never see the speed (rpm) or turns change, and angle just steps up forever even if the throttle is up, like in this post: viewtopic.php?p=32932#p32932 .
Thanks!
-- Joe
The problem is that the motor doesn't turn smoothly. I'm getting that jogging/cogging/clunking thing that implies the encoder wires are swapped. I've read through a lot of forum posts trying to figure out how to fix this.
I'm using the default inverter settings, except:
- udcmin is 0v
- udcsw is 15v
- potmin and potmax were adjusted for my throttle.
What I've done so far:
- Swapped the encoder wires. Same result.
- Unplugged the encoder entirely. Same result.
- Tried changing encmode to A, but that had no effect (I set it back to AB, which as I understand it is what Tesla motors should always be set to due to the quadrature encoder).
I then wanted to test the encoder itself. Since I don't have an oscilloscope to play with, I connected it to a logic analyzer. I powered the encoder directly with a 5v bench power supply. It was not connected to the OpenInverter board, which I used to spin the motor with a dedicated 12v power supply and the two 12v batteries. My motor didn't come with shafts, so it's difficult to spin it diff by hand; I'm assuming that you have to hold one side still while you turn the other side for the encoder to pulse. Having the OpenInverter board turn it seemed simpler.
Now, importantly, I screwed up my encoder test by mistakenly swapping the 5v and ground from my ben ch power supply to the encoder. I feel like this PROBABLY didn't kill the encoder, but I'm not entirely sure, mostly because I don't know how this particular encoder works (is it hall-based or optical or what) and how sensitive it is to reverse polarity. I feel like it's probably fine, but since I could never get anything out of it to begin with, I'm not entirely sure.
Mind you, it wasn't working before I reversed the polarity, so that's not the root cause of my problem.
So my questions are:
- How can I be sure the encoder works?
- Did I kill the encoder with reverse polarity?
- if I did, does anyone know the part number of the encoder so I can replace it?
- Is there a way to see the raw encoder values in the OpenInverter web interface? I never see the speed (rpm) or turns change, and angle just steps up forever even if the throttle is up, like in this post: viewtopic.php?p=32932#p32932 .
Thanks!
-- Joe