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DIY Turbopump Controller

Posted: Thu Jan 14, 2021 1:39 pm
by Nicolas Krause
While I've purchased a TPM 50 turbopump for 100$ off of eBay, the device did not come with a controller. I'm unable to afford the purchase price of a new turbotronik controller, and while I've been looking on eBay, I haven't seen one come up for a price I can afford. I have a portion of the circuit completed in KiCad and I'm at the point where I have to start designing to power supply for the whole shebang. I'll need three different power levels, a 3.3V for the microcontroller and LCD screen, 15V for the driver chip (a FAN7388) and then 200V for the IGBT's that make up the driver circuit for the motor itself. I've been looking at the specs of the TurboTronik controller and it states that on startup it'll draw a maximum of 45W of power or 64VA. Given that it also specs that the voltage for each phase of the motor is 150V I've calculated the max current as 64VA/(1.73*150V)=246mA. So with a bit of a safety buffer a 200V supply that can also give up to 300mA of current should be alright no? This is the first time I'm designing an electronics project with this many moving parts and I just want to confirm I'm getting the basics right as I go forward.

Re: DIY Turbopump Controller

Posted: Thu Jan 14, 2021 1:59 pm
by John Futter
Nicolas
Look up my previous posts on this
I've built around 20 controllers for these. I used a simple 35-0-35 volt transformer to give me relay selected voltage of 45 volts and 90 volts to run the pump.
i switched supplies at approx half freq

Re: DIY Turbopump Controller

Posted: Thu Jan 14, 2021 2:23 pm
by Nicolas Krause
Thanks for the reply John, I've found your design on the coulter smithing forums. Just to confirm a couple of things I'm reading about the device.
  1. There's no magnet sensor on the TPM 50
  2. Your design uses no microcontroller, but there is some digital logic, it looks like there's an output I assume to a computer down the line?
  3. If I run the pump at 90V will I get full RPMs? Or is the 150V the manufacturer specced just a standard engineering safety margin?

Re: DIY Turbopump Controller

Posted: Sat Jan 16, 2021 9:03 pm
by John Futter
Nicolas
The NT10 /NT13 controllers that were used we these devices used pwm and turned the pwm on / off so you heard a zip zip noise from the motor.
they used the on / off so they could use the higher voltage and still keep the motor windings cool.
My design did use a micro to generate the main freq to the 3phase logic generator and driver so micro did only monitor motor current and based on current it incremented the frequency when the motor current was below two amps. Net effect was the unit would accelerate to full noise in about 3 minutes in a leak free system.
Sorry did not include the micro stuff as it was proprietry to work ( some one elses work)

Re: DIY Turbopump Controller

Posted: Sat Jan 16, 2021 10:11 pm
by Nicolas Krause
I'd read that it was proprietary work on the original thread, no worries there, looks like a fun project for me to add a microcontroller. Besides, I've got a lot more faith in your circuit design skills than mine when it comes to the driver portion! I'm in the process of replicating your circuit at the moment in KiCad, I'll probably figure out all the components and circuit operation and then work on adding some firmware to control the whole thing.

Re: DIY Turbopump Controller

Posted: Sun Jan 17, 2021 12:44 pm
by John Futter
i'll post some more when I get to work
I havent been there since 22/12/20 big holiday wiring up my new house

Re: DIY Turbopump Controller

Posted: Fri Jan 22, 2021 2:03 pm
by Nicolas Krause
Hi John,

I've got a first draft of your schematic done up in KiCad, still have to build a bunch of footprints and possibly swap out a component or two, but lot of the basic work is done. I've also ordered a couple of the new Raspberry Pi Pico microcontrollers. They're very cheap, 4$, and seem to meet all the specs for what I need to do. So the next steps are to figure out the connections between the Pico and the pump controller circuit and then I can move on to layout once I've got a final version of the schematic.
Capture.PNG

Re: DIY Turbopump Controller

Posted: Sat Jan 23, 2021 4:19 pm
by Peter Schmelcher
Nicolas these are internal pics of my NT10 controller circuit board before I repaired it but after cleaning with compressed air. It had previously been repaired by someone and was sold "as is". Unfortunately, I never found any schematics so I repaired it using these pics.

The NT10 controller spins up the turbo in discrete drive frequency steps with coasting between frequency increases. During the coasting moments the voltage produced by the motor windings are measured and used as a tachometer reading. As I recall the turbo needs to spin up within 2 minutes getting quickly through a 50Krpm mechanical rotor resonance.

Today my plan B repair would be a new variable frequency drive for a CNC router spindle ($130). The faster VFDs run up to 1000 Hz and I suspect that with a crystal change hack one could increase the upper frequency.
-Peter

Re: DIY Turbopump Controller

Posted: Sat Jan 23, 2021 6:31 pm
by Nikodem Czechowski
Nicolas Krause wrote: Fri Jan 22, 2021 2:03 pm Hi John,

I've got a first draft of your schematic done up in KiCad, still have to build a bunch of footprints and possibly swap out a component or two, but lot of the basic work is done. I've also ordered a couple of the new Raspberry Pi Pico microcontrollers. They're very cheap, 4$, and seem to meet all the specs for what I need to do. So the next steps are to figure out the connections between the Pico and the pump controller circuit and then I can move on to layout once I've got a final version of the schematic.

Capture.PNG
Can you share the schematics in KiCad? Would love to join the work, I can (help) design the PCB, if you would like. Especially that I am looking for a controller for my Turbovac 50 :wink:

Re: DIY Turbopump Controller

Posted: Sat Jan 23, 2021 8:16 pm
by Nicolas Krause
Peter, thank you for photos and explanation of how the device measures the turbopump speed. I think at this point I'll press on with the custom design rather than the VFD option given the work John has already put into the circuit design.

Nikodem, I'm happy to share the schematic, I should warn you that it's missing some details and I swapped in some components I was missing in the library rather than build them out. It's a first draft, and I still have to put in connections for the microcontroller, LCD screen, on/off switch etc... As far as helping with the PCB design, I appreciate the offer but I like the work and I need the practice!

Re: DIY Turbopump Controller

Posted: Sun Jan 24, 2021 5:02 am
by Nikodem Czechowski
OK Nicolas :) If you would need any assistance with PCB and electronics, feel free to ask.

Re: DIY Turbopump Controller

Posted: Sun Jan 24, 2021 5:49 am
by Jerry Biehler
I have an official schematic for the controller for these pumps. https://drive.google.com/file/d/0B1bUBQ ... sp=sharing

There are about 4 drive models that will run this pump, the NT10, NT12, and NT13 as well as the NT50 which I have provided the schematic for. Sometimes these models do pop on ebay at reasonable prices. I also may know someone with working NT50s for sale. I think there is a NT11 but I have never seen one.

Re: DIY Turbopump Controller

Posted: Sun Jan 24, 2021 7:49 am
by Nikodem Czechowski
Jerry Biehler wrote: Sun Jan 24, 2021 5:49 am I have an official schematic for the controller for these pumps. https://drive.google.com/file/d/0B1bUBQ ... sp=sharing

There are about 4 drive models that will run this pump, the NT10, NT12, and NT13 as well as the NT50 which I have provided the schematic for. Sometimes these models do pop on ebay at reasonable prices. I also may know someone with working NT50s for sale. I think there is a NT11 but I have never seen one.
NT50 seems to be overly complicated and based on discrete ICs and logic - a thing, that easily can fit into an Arduino module. I would not recomend replicating it nowadays. Maybe the driver stage, of the transistors are still available.

Also - what is a reasonable price for this controllers?

Re: DIY Turbopump Controller

Posted: Sun Jan 24, 2021 10:36 am
by Richard Hull
Nikodem, please do not include quotes from the same thread. We are following it just fine. We have to tell this to many people who come here. I realize they are the norm on many sites. However, we are capable of fully and properly following a single post thread through all of its reply postings. Just simply reply without quoting something that is either immediately above or even 5 posts back in the thread, we will know what you are talking about in reply.

Richard Hull

Re: DIY Turbopump Controller

Posted: Sun Jan 24, 2021 1:40 pm
by Nicolas Krause
Thank you Jerry, that's sure to prove useful! As far as prices for a controller on eBay, my pump was 100$ w/out a controller, I routinely see Turbotroniks listed for over $1000, and unfortunately haven't had any look looking for cheap ones.

Re: DIY Turbopump Controller

Posted: Mon Jan 25, 2021 7:24 am
by Rex Allers
Jerry,
I guess you posted the scans of the NT50 controller a few years back as I have a saved copy. (Not sure if the post was here or Coulter.) Anyway, I took your separate page scans and merged the ones that make up just the schematic in to one single big PNG file. There are other pages in your scans that have info besides the schematic so my pic isn't all of it.

I have just uploaded it here:
http://www.xertech.net/pub/NT-50_joined_1.png

Feel free to copy it and add to your page if you desire.

The size is actually smaller than your single page scans. I reduced the pixel dimensions to 1200 vertical and applied contrast to make more black and white. I think it is still quite readable in my version.

Re: DIY Turbopump Controller

Posted: Tue Jan 26, 2021 6:12 pm
by Peter Schmelcher
Jerry thanks for the NT50 schematic and Rex for combining the sheets, both are downloaded for a future traumatic rainy day.
The information provides lots of clues for trouble shooting my similar NT10.

For the younger fellows, reverse engineering a black box is a miserable repair procedure and even if successful you still can’t be certain that the repair is behind you until you have lots of miles on the repair.
-Peter

Re: DIY Turbopump Controller

Posted: Thu Feb 04, 2021 9:57 pm
by Nicolas Krause
I've hooked in the microcontroller, LCD, and on/off switch on the current schematic. Still lots of details left to verify though. I can't seem to attach the file to the message board but if you PM me I'll happily provide the file to any interested parties. I do have a question about the connectors to the transformers though, I'm not 100% sure on their use. I don't think they're necessary to hook into the microcontroller but I could be wrong?
Capture.PNG

Re: DIY Turbopump Controller

Posted: Fri Feb 05, 2021 3:35 am
by ArkadiuszGibes
Hi guys

I already made driver for Turbovac 50. You can see it here https://www.youtube.com/watch?v=HPkOAWe2w2c - it's part of my rotor balancing "toy" now.
The project is based on https://github.com/NiklasFauth/stm32-turbotronik - it's not mine. I did some changes to it and it works well. If someone would like i can shere PCBs and schematic. There is also DC/DC (mains/200V) converter that i made for this pump, but it requires to wind the transformer and the one that i used was just some old crap which i took out from old TV. I will try to prepare some more detailed description soon. Im at work now .

Best Regards
Arek

Re: DIY Turbopump Controller

Posted: Fri Feb 05, 2021 3:50 am
by Nikodem Czechowski
Hi Arek!

Please do share your schematic and PCB. I thinks this is what I'm looking for for my TMP

Re: DIY Turbopump Controller

Posted: Fri Feb 05, 2021 10:31 am
by ArkadiuszGibes
Hi

Here is a repository with kicad files: https://gitlab.com/arkadiusz.g/turbotronik1.0hw/
However, that was the first version of this driver, so it has some issues. One of them is LDO regulator, there is to much current that goes trough it and it is getting hot quite fast. I replaced it with Chinese dc/dc reg and it's fine - this is not updated in those pcb files.
This is a dc/dc converter that i used - https://allegro.pl/oferta/modul-przetwo ... 7563986495,
Also, as i built in on top of someones else code, it is using lcd that is driven by i2c -> parallel IC. From what iv'e seen, sometimes it was crashing so I had to repleace it with other type of lcd in my case.

Would be nice to update those files with DC/DC instead of LDO, and rebuild it with standard parallel interface for LCD so it could be used with cheap 2x16 displays. I can do this in free time, but feel free to do any modification you like.

Nikodem, I see that you are from Poland, if we would fix those "bugs" somehow then we could send it to production to china, and share some costs for pcbs.

Re: DIY Turbopump Controller

Posted: Sun Feb 07, 2021 5:26 pm
by Nikodem Czechowski
I will download the files tommorow and try to do the updates you have mentioned.

What pump you would want to drive it?

We can share the costs, I would ever need 10 pcbs for that - PM me and we can discuss the details.

Re: DIY Turbopump Controller

Posted: Mon Feb 08, 2021 3:47 am
by ArkadiuszGibes
Right now im playing with turbovac 50 pump, but it's damaged and i ordered turbovac360V. I will need to do some changes because TMP 360V works on lower voltage and frequency, but this is in most stuff that can be done by FW modifications. I will also repleace my 200V dc/dc converter to toroid transformer. Please shere the files when you update them.

Thanks

Re: DIY Turbopump Controller

Posted: Mon Feb 08, 2021 5:29 pm
by Nicolas Krause
Hi Akradiusz, thanks for the links and files. If I could ask you to introduce yourself on the welcome forum it'd be a big help. The rules the old timers have setup here really help to preserve the quality of information on the forum!

Re: DIY Turbopump Controller

Posted: Tue Feb 09, 2021 3:19 am
by ArkadiuszGibes
I already did it.