OpenInverter Mainboard in a Siemens Simotion?

Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Dear everyone,

I am quite new to the EV-world, and have recently bought my first EV project. It contains a Siemens Simotion controller from the 90's-2000's that was built in the Think City (or Think Classic) cars.

Does anyone have experience in working with this type of controllers? I know they are older than what people typically seem to be working on here, but the electronic components are not that different, I think. I have been trying to get the controller to work with the original logic board, but to no avail. In order to communicate with the controller, specific adaptors, serial communication with an old computer (386 or 486 processor), and the right version of the Siadis (by Siemens) software is needed. In order to change any parameters, one needs two access codes, which only Think could give, which does not exist anymore. In one word: complicated.

I am starting to think this is not going to work in the way Siemens wants me to do it, and I am wondering whether the OpenInverter main board could be the way forward. In that way, I would have a better understanding of what is happening and hopefully more control. Moreover, I think the OpenInverter project is a great initiative and I want to support it.

Does anyone have experience with swapping the logic board on a Siemens (either Simovert or Simotion) inverter? I have peeked inside the controller, and saw that there are about 10 data transmitting wires connecting the logic board to the driver board. 6 of those are 'grouped' on the logic board, I am suspecting that these might be linked to the L1,2,3 High and Low.

Additionally, there is a 12V power connector between logic board and driver board. When the controller is 'on', the driver board uses about 1A (at 12V). The 6 'grouped' wires are all set to +5V compared to the negative of the power supply line. In that situation, the resistance between battery poles and L1,2,3 is in the MOhm range.

I think there might be two current sensors built into the layer with IGBTs, but I can't really see what is in there unless I really open up the IGBT layer which seems glued together. See attached pictures for details.

Does anyone have tips on how to proceed, or can someone tell me whether this is even possible what I have in mind? For example, how can I test whether these six wires are indeed connected to the three phase High and Low parts?

Cheers,
Bart

Attached are some pictures.

PS: I am a mechanical engineer by training, so forgive me if I sometimes misunderstand. My last project was a rebuild of a DC motor controller for a special e-bike hub, see here: https://tinkertalkingb.art.blog/2020/02 ... nyo-cmu-1/ if you are interested.
Attachments
Motor label: The specifications of the Siemens motor
Motor label: The specifications of the Siemens motor
Maybe a current sensor board: There are two boards like these connected to a 'block' containing the IGBTs
Maybe a current sensor board: There are two boards like these connected to a 'block' containing the IGBTs
Here are the six pins that exit the Siemens logic board to connect to the driver board.
Here are the six pins that exit the Siemens logic board to connect to the driver board.
The entire inverter without the busbars
The entire inverter without the busbars
The entire inverter with the outside cap removed
The entire inverter with the outside cap removed
The entire inverter with the outside cap removed
The entire inverter with the outside cap removed
The specifications of the inverter
The specifications of the inverter
The entire inverter as it would be built into a vehicle.
The entire inverter as it would be built into a vehicle.
User avatar
johu
Site Admin
Posts: 5684
Joined: Thu Nov 08, 2018 10:52 pm
Location: Kassel/Germany
Has thanked: 153 times
Been thanked: 960 times
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by johu »

5V idle sounds like low active drivers. Will work as is driven from the STM32.
The other signals are probably voltage and currents. Just feed some current through the sensors at bus bar exit and see if anything changes on the remaining pins. There is also a resistor chain on the driver board, most likely for bus voltage sensing. Again, feed in some voltage and observe the change.
With that figured out you've pretty much solved it and entered open inverter world :). Extra points awarded for finding a possible desat and other error signals.
Maybe you have to run this at 4.4kHz as it's rather old, can you find something on it?
Support R/D and forum on Patreon: https://patreon.com/openinverter - Subscribe on odysee: https://odysee.com/@openinverter:9
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Thank you for the very quick and useful reply! And it sounds very promising :). The low idle drivers would become active when a pin is set to ground, or something else like -5V? Can I test the closing of IGBTs by a simple resistor check across battery bus bars and L1/2/3?
You say there is a resistor chain on the driver board, did you see it from the pictures, or do you suppose there must be one on there?
I will investigate the other pins later, when I can let some current through one of the busbar pins, IGBTs, and motor pins, and test the current sensors.
About the switching frequency: I cannot find that information on the boards, and I don't know what the original switching frequency was... Is that a problem, since I read that main board version 3 has a switching frequency fixed at 17 kHz?
By the way: a strange phenomenon I observed: When I connect the driver board pins directly to my DC power supply, the power supply seems to shoot to a high current at around 8 Volt or so, and then the current limiter is activated... Something similar happens when I turn on the driver board via the logic board, if I set the current limiter on the power supply too low. There is maybe some component on the driver board that causes this effect? It could also be my power supply acting up, I don't know.

Cheers, Bart
User avatar
johu
Site Admin
Posts: 5684
Joined: Thu Nov 08, 2018 10:52 pm
Location: Kassel/Germany
Has thanked: 153 times
Been thanked: 960 times
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by johu »

The 74ACQ573 chip gives it away - it's simple inverted 5V logic. 5V: IGBT off, 0V: on.
Resistor chain is on the gate drive board between 1st and 2nd channel.
What you are seeing is inrush current, be more genourous with your current limit.
Where did you read frequency is fixed to 17kHz? It can be 4.4, 8.8 or 17.6
Support R/D and forum on Patreon: https://patreon.com/openinverter - Subscribe on odysee: https://odysee.com/@openinverter:9
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Thanks again for the fast reply!
About the 0-5V: I should have figured that out from the latch, that was my mistake. Ok, I will try applying 0V to each of those channels one by one and observe whether an IGBT responds to it.
Ok, thanks about the tip on inrush current! I will see whether a higher current limit does the trick, just didn't want to change that with the risk of breaking something.
About the switching frequency: I read that here https://openinverter.org/wiki/Main_Boar ... WM_outputs, where it says: "The frequency is fixed to 17kHz". I will try to find out more about the simotion specs, maybe I can find out what it originally was. Does it hurt in any way to have a lower switching frequency? Or is it just the audible noise that is disturbing?
Cheers,
Bart
User avatar
johu
Site Admin
Posts: 5684
Joined: Thu Nov 08, 2018 10:52 pm
Location: Kassel/Germany
Has thanked: 153 times
Been thanked: 960 times
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by johu »

Bart wrote: Tue Feb 11, 2020 8:57 am About the switching frequency: I read that here https://openinverter.org/wiki/Main_Boar ... WM_outputs, where it says: "The frequency is fixed to 17kHz".
Oh, right, that is misleading. Have clarified it.

Lower frequency just means more audible noise and a bit higher losses in the motor. Nothing too worrying.
Support R/D and forum on Patreon: https://patreon.com/openinverter - Subscribe on odysee: https://odysee.com/@openinverter:9
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Hey,
Sorry for the delay, I just started a new job, so had only few opportunities to work on the project.
I have now verified that the six channels are indeed connected to the six IGBTs, and they all work. I have also found the voltage sensing channel. I find it hard to find the current sensing channels, as I don't really know an easy and safe way to send high enough currents through these transistor to make a measurable signal. I was wondering: does the openinverter board allow control without current feedback? In that case I could let the motor run and make that pull some current.
I have position feedback through the quadrature encoder, which is also tested and working.
I would also still like to find the desaturation signal, maybe by opening both L1 high and low, with a heat-dissipating resistor in series with the battery. Is it common to use 0-5V logic on these error signals?

Anyway, if the openInverter board can run without current feedback, I think I should try to take the next step and get going with an openinverter board :).

Bart
User avatar
joromy
Posts: 371
Joined: Fri Jun 28, 2019 12:56 pm
Has thanked: 1 time
Been thanked: 3 times

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by joromy »

switching frequency is 6Khz
sine wave in 0.7...400 Hz range, which corresponds to max 12,000 RPM
invetrer.JPG
Have a look at the schematics here, that is very similar to the Simotion.
viewtopic.php?f=16&t=186
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Thanks!

I did not know that the Ford ranger EV also uses a Siemens motor and inverter. They seem to have quite some power, more than I expected.
About the encoder: do you know the amount of block signal periods per engine revolution in your motor? It might also be the same for both motors, and at the moment I don't know what mine has, and don't know an easy way to find out.
The connector of your inverter to the outside world is different; mine uses a single, 68-pin connector. I think I could still use that connector soldered to a perforated board, and go from that board to the brain board.
I guess I could use the standard OpenInverter board (community), and then work with 4.4kHz?

Thanks again,
Bart
User avatar
johu
Site Admin
Posts: 5684
Joined: Thu Nov 08, 2018 10:52 pm
Location: Kassel/Germany
Has thanked: 153 times
Been thanked: 960 times
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by johu »

Bart wrote: Mon Mar 30, 2020 6:41 pm Anyway, if the openInverter board can run without current feedback, I think I should try to take the next step and get going with an openinverter board :).
Yes it can: https://openinverter.org/wiki/Schematic ... te_drivers
Support R/D and forum on Patreon: https://patreon.com/openinverter - Subscribe on odysee: https://odysee.com/@openinverter:9
User avatar
joromy
Posts: 371
Joined: Fri Jun 28, 2019 12:56 pm
Has thanked: 1 time
Been thanked: 3 times

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by joromy »

This is the Think motor.
1lh5118-.jpg
size.JPG
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
User avatar
joromy
Posts: 371
Joined: Fri Jun 28, 2019 12:56 pm
Has thanked: 1 time
Been thanked: 3 times

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by joromy »

Have you considered to use it as it is?
The setup looks quite easy.....

Think_inverter.JPG
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Thank you for the help!
I have now received the main board (Rev 3, community edition), and started playing with it. It is really a great thing to work on something that is not designed to keep me out, but designed to help me get into the wondrous eV world :).

I have powered it up, managed to wirelessly connect and change configurations. As a first try, I connected the motor thermistor (a KTY84), and tried to log the motor temperature over time. This worked for a while, then the plot froze. Upon refresh, I have not managed to get the parameters and spot values on the browser screen anymore. This problem is reproducible on a Linux, Windows and Android system. Does anyone recognize this behavior? Attached is a printscreen of the web interface (see the 'loading' circles at both the 'Parameters' and 'Spot values' headers, the console never actually loads these values). Is this what is meant with a 'locked up' board? In any way, the power LED is on, and the 'alive' LED is blinking happily.

Some small notes:
Thanks a lot for all the documentation on the wiki page, it is very helpful! I think I have found a few inconsistencies:
- In this schematic https://openinverter.org/wiki/File:Main ... out_v3.png, it is written that JP2.2 is at 5V (for encoders), but I think this should be JP2.4 (This is at least what I measured, and also what is written in the letter attached to the package of the main board). JP2.2 is a GND connector, and together with 5V from JP2.4 it can power the encoder.
- The digital input for error, as described herehttps://openinverter.org/wiki/Main_Board_Version_3 is nr 14, according to drawing here https://openinverter.org/wiki/File:Main ... out_v3.png, while nr 13 is written on the wiki (which should be the FWD select pin).

Happy Dutch king birthday,
Bart
Attachments
Inverter parameter console_freeze.PNG
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

joromy wrote: Wed Apr 01, 2020 8:31 pm Have you considered to use it as it is?
The setup looks quite easy.....
Hey Joromy,
thanks for the post. Yes, the setup looks easy, but that schematic is not from the Think version, which has its own software (Siadis) version on it and different hardware it connects to. I have spent months trying to make progress in connecting and knowing what to do, but it is so old that it is very hard to find a computer that can talk with it, the right Siadis version for the computer, the Siemens unlocking code, etcetera. I would certainly have preferred to not having to build in a new board, I simply do not have the means or knowledge to do it. I hope that the OpenInverter will not make me go through that again, I have hopes that it will work out :).
The motor in that picture looks a lot nicer than mine, but it looks to be the same model, that is right :).

Cheers,
Bart
User avatar
joromy
Posts: 371
Joined: Fri Jun 28, 2019 12:56 pm
Has thanked: 1 time
Been thanked: 3 times

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by joromy »

Bart wrote: Tue Apr 28, 2020 7:36 pm Yes, the setup looks easy, but that schematic is not from the Think version, which has its own software (Siadis) version on it and different hardware it connects to.
I didn't mean that you should use Siadis to reprogram it, but use it as it is used in the Think, with same voltage range, switches throttle an so on.
But maybe you have found out more.......

You could also try to talk to prensel, I think he knows a lot about Think.
Location: Nijmegen (NL)

He sign his post with:
= Th!nk PIV4 Collection, support, sales =
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
User avatar
joromy
Posts: 371
Joined: Fri Jun 28, 2019 12:56 pm
Has thanked: 1 time
Been thanked: 3 times

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by joromy »

Bart wrote: Mon Apr 27, 2020 6:26 pm (see the 'loading' circles at both the 'Parameters' and 'Spot values' headers, the console never actually loads these values). Is this what is meant with a 'locked up' board? In any way, the power LED is on, and the 'alive' LED is blinking happily.
If you don't get some reply on this, have a look in "web interface" tread, especially the "HOWTO: Flashing ESP8266" tread.
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
User avatar
johu
Site Admin
Posts: 5684
Joined: Thu Nov 08, 2018 10:52 pm
Location: Kassel/Germany
Has thanked: 153 times
Been thanked: 960 times
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by johu »

If the processor "reboots" while the ESP8266 does not communication breaks down. Reason: STM32 starts up at 115k communication and can be switched to 1M communication. If it reboots its back to 115k but ESP still runs at 1M. Power cycling everything should help.
Support R/D and forum on Patreon: https://patreon.com/openinverter - Subscribe on odysee: https://odysee.com/@openinverter:9
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Thanks for the advice, now it works! I think I made the mistake of slowly increasing the voltage of my power supply, which made the ESP8266 already start (at 3.3V), while the processor was still off? Anyway, now it works every time I reboot/power up, it is great to be able to change parameters knowing it will still be possible to change once it is built into the car. Luckily I did not need to flash the ESP8266.

I have now calibrated the BUS voltage readout, I can read the motor temperature sensor, which is the KTY84 sensor in this Siemens motor (By the way, I found that the software wants 'snsm' to be set at 11,12,13 rather than 1,2,3 as written here https://openinverter.org/wiki/Parameters).
I have also connected the quadrature encoder (open collector), and can see very nice block signals sent into the openinverter board (to JP2,1 and JP2,3). When I choose either encmode = 1 (quadrature encoder) or encmode = 2 (quadrature /w index pulse), I see no registration of speed when hand-turning the motor either direction (using the plot function in the interface). When I choose encmode = 0 (single encoder), I do see the speed being registered. I might do something wrong here, but I found no obvious error so far.

As discussed in the beginning of this thread, the gate driver board has an active LOW PWM polarity. Does this mean I need a pull-up resistor to each driver channel (L1,2,3 High/Low), or is changing the pwmpol parameter enough?

Otherwise, I am making progress thanks to all the documentation and help from the forum threads, thanks again :).

/Bart
User avatar
joromy
Posts: 371
Joined: Fri Jun 28, 2019 12:56 pm
Has thanked: 1 time
Been thanked: 3 times

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by joromy »

Bart wrote: Wed May 06, 2020 8:26 pm As discussed in the beginning of this thread, the gate driver board has an active LOW PWM polarity. Does this mean I need a pull-up resistor to each driver channel (L1,2,3 High/Low), or is changing the pwmpol parameter enough?
When I made the board for the Ford Siemens inverter (also with LOW polarity), I found out that the driver board already had 20k pullup resistor to 5V.
You could measure the resistance to 5V and see what impedance you get.
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Thanks Joromy!

I have been experimenting a bit more now. The quadrature encoder is now read correctly by the software, although I don't know what has changed. I suspect the software only starts reading the speed (RPM) when the inverter has been 'started' (opmode=1).

I have simulated the current sensor by feeding the pins 1.83 V (= 2.5V (Voltage at zero magnetic field of Melexis MLX91205), * 3.3kOhm/4.5kOhm (resister divider)).

The microcontroller has 'FOC' software installed on the microcontroller (it says: Version:4.77.R-foc), and the parameters fslipspnt, boost, fconst, udcnom, etc are all missing, but all the 'FOC' parameters (curkp, curki, etc) are defined. I would like to keep things simple and use the 'sine' version. I never got to operate in manual mode (opmode=2), only "run" mode (opmode=1), and always see the warning WARN - HICUROFS1 and WARN - HICUROFS2.

Is it possible to upgrade the firmware by a 'sine' version from this binary (https://github.com/jsphuebner/stm32-sin ... ag/v4.76.R ) via the web interface? Or does that somehow require more steps, for example regarding parameters? I couldn't find any forum posts on this particular topic of shifting from sine to/from FOC, that is why I ask it here.

/Bart
Isaac96
Posts: 656
Joined: Sat Oct 05, 2019 6:50 pm
Location: Northern California, USA
Been thanked: 1 time
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Isaac96 »

FOC is used for permanent magnet motors. Sine is used for induction motors. That looks to me like an induction motor, so probably use the sine firmware.

The current sensor pins should be fed 1.65v, that is the ideal midpoint.

Just upgrade the firmware with the sine version. Then probably restore the default parameters.
Also set fmin to 0.5 and fslipmin to 1.5.
-Isaac
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Thanks Isaac for the confirmation, and additional info! I got to upload the 'sine' version successfully, that was a lot easier than I feared :).

I have now run the inverter in manual mode, and got some PWMs out of it. All good on the main board right now :).

There is also some progress on the interface to the driver board:
- I have identified most of the 40-pins in the ribbon cable that ran from the driver board to the original brain board. If anyone is interested in knowing them, I can compile a list.
- There are three heat sink temperature sensors (PTC), for L1, L2, L3, at about 960 Ohm at 22 degrees. These could thus be KTY81 sensors.
- The current sensors are attached to L1,L2, and send out a signal voltage of about 13 and -13 Volt. I don't know how these voltages depend on current yet, but anyway I think I will try to build in a magnetic field sensor as Johannes' sense boards do. That would spare me from a lot of work with trying to read out the original sensors, I think.
- I would still have to see if I can find a desat signal coming from the driver board. If I read it correctly from Joromy's schematic drawings, the desat signal is not built into the driver board of the Ford Ranger (viewtopic.php?f=16&t=186#p1869), so it might be missing on this board as well, and rather be built on the original brain board.
- I found out I do need a pull-up resistor at the PWM pins, so I will add a 20k pull-up resistor to each.

Next steps are to connect the very thin 40-pins ribbon cable to the openinverter main board, and to build current sensors.

/Bart
User avatar
joromy
Posts: 371
Joined: Fri Jun 28, 2019 12:56 pm
Has thanked: 1 time
Been thanked: 3 times

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by joromy »

Bart wrote: Thu May 21, 2020 10:08 am - The current sensors are attached to L1,L2, and send out a signal voltage of about 13 and -13 Volt. I don't know how these voltages depend on current yet, but anyway I think I will try to build in a magnetic field sensor as Johannes' sense boards do. That would spare me from a lot of work with trying to read out the original sensors, I think.
- I would still have to see if I can find a desat signal coming from the driver board. If I read it correctly from Joromy's schematic drawings, the desat signal is not built into the driver board of the Ford Ranger (viewtopic.php?f=16&t=186#p1869), so it might be missing on this board as well, and rather be built on the original brain board.
I would not use the magnetic field sensor, they are not very reliable.
If you do a DC amp test, with 10 winding's (or more) and run 0-50 amps trough it you will probably get a nice linear 0-500A curve.

Regarding the desat, I have not investigated the PIN 14 in the schematic: download/file.php?id=999
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
Bart
Posts: 25
Joined: Fri Feb 07, 2020 1:23 pm
Location: Netherlands
Contact:

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by Bart »

Thanks for the quick reply Joromy!
joromy wrote: Thu May 21, 2020 10:53 am I would not use the magnetic field sensor, they are not very reliable.
If you do a DC amp test, with 10 winding's (or more) and run 0-50 amps trough it you will probably get a nice linear 0-500A curve.
I would certainly prefer to use the existing current sensors. Unfortunately, it is quite impossible for me to reach it, and I therefore can't run multiple loops through it. In the bottom of the attached picture, you can see the transparent flat cables in the bottom, they must lead to the actual sensor, which is built into this huge block. I could remove the lid from that block, but I am a bit afraid to damage something.
Another problem is the calibration of the sensor signal in the openinverter software. I have to do quite some reshaping of the signal in order to get signal that is even close to the expected signal as produced by the magnetic field sensors, including inversion of the polarity.
joromy wrote: Thu May 21, 2020 10:53 am Regarding the desat, I have not investigated the PIN 14 in the schematic: download/file.php?id=999
Ok, I will see if I can find a 'fault'/desat channel, would be good to include. I will update on that.

/Bart
Attachments
This is the bottom of the Siemens gate driver board: you can see the six drivers at the top. At the bottom, the two small PCBs are current sensor boards. I think the flat cables lead to the actual sensors, hidden in the white block at the bottom.
This is the bottom of the Siemens gate driver board: you can see the six drivers at the top. At the bottom, the two small PCBs are current sensor boards. I think the flat cables lead to the actual sensors, hidden in the white block at the bottom.
User avatar
joromy
Posts: 371
Joined: Fri Jun 28, 2019 12:56 pm
Has thanked: 1 time
Been thanked: 3 times

Re: OpenInverter Mainboard in a Siemens Simotion?

Post by joromy »

Bart wrote: Thu May 21, 2020 4:16 pm I would certainly prefer to use the existing current sensors. Unfortunately, it is quite impossible for me to reach it
Ok, I will see if I can find a 'fault'/desat channel, would be good to include. I will update on that.
I agree about the current sensors, they look strange, they have gone for more normal ones in the Ranger.
I'm very interested about your desat findings, please keep me updated on that!

Maybe you can see some similarities, with the Ranger IGBT driver board
IMG_20190916_172400_5 (1).jpg
Edit:
There is a opto coupler on each IGBT driver circuits that goes to the input of OR gate and then to pin 14 on logic board (22k pullup to 5V) It is pulled LOW all time with a transistor on the OR gate output.
I think this could be DESAT, maybe something similar on your board.

Do you have a picture of the component side?
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
Post Reply