Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

[Astro]

I have been thinking about how i am going to mount the controller and i had assumed mounting it flat with the thick plate at the bottom would be the best.
But then the images others have posted of things coming loose in the post has me concerned.
The postal service may be rough with packages but i imagine the engine bay of our cars will be rougher.
Would mounting the controller inverted with the thick plate at the top be better so that the capacitor isn't hanging from the top of the housing?
I have terrible visions of going over a significant bump in the road and the capacitor dropping down onto the IGBTs.

Paul, is the ring capacitor polarity sensitive? I keep thinking about my earlier suggestion of the copper rings to give a solid mount to the capacitor. Could the IGBT's be turned around so that the driver pins were on the outside of the rings rather than the inside? Then there would be room to put the driver circuits outside the rings.
Just a thought.

[MPaulHolmes]

I didn't bolt the cap down in shipping. It mounts to the enclosure with 4 bolts and doesn't bounce around. Going over a bump won't matter. You can mount it any way and nothing comes loose when it's all bolted together. I was just trying to save time with shipping the others out.

[cts_casemod]

Are you shipping kits yet Paul, or just "test versions"?

I'm still up for that control PCB when you have stock again.

CS.

[Astro]

Originally Posted by MPaulHolmes

I didn't bolt the cap down in shipping. It mounts to the enclosure with 4 bolts and doesn't bounce around. Going over a bump won't matter. You can mount it any way and nothing comes loose when it's all bolted together. I was just trying to save time with shipping the others out.

Whew, good to know.

Thanks for that information Paul, puts my mind at ease.

I just ordered the rest of the batteries for my EV conversion, it's getting exciting now.

Now i just need an excellent image or logo to put on top of the controller. The controller will be mounted above the motor and will take up most of the engine bay. So i think it should not only work well but should look good as well. It will be the main thing that is visible when i open the hood.
I think i will avoid the use of sparks or lightening bolts as this may give the wrong impression. Sort of like a petrol tanker with flames painted all over it.

[thingstodo]

Originally Posted by MPaulHolmes

... I was just trying to save time with shipping the others out.

Does that mean you're close to shipping out my AC drive?

I have not seen a cost for shipping as yet .. did I miss it?

And I'm in for extra control boards, when you are ready to go into production. I need a brain transplant for 'several' industrial drives that are going to be re-tasked.

[Astro]

Originally Posted by e*clipse

I didn't modify my toaster oven. I've seen things where people added fancy PID controls; I just got a good digital thermometer and documented the response.
I did get one only for soldering - they're pretty cheap anyway - just so whatever weird fumes come from soldering don't infect our food.
For this job, I'll just solder it by hand. Hopefully I'll retain some sanity - this is the tightest board I've ever dealt with. LOL!

e*clipse, i used a hot air soldering station to do all my BMS modules and it made the process quite easy. If there were any issues like a resistor standing up due to surface tension (happens occasionally, depends on amount of paste you use) then it was simple to just push it back down with tweezers while the solder paste was still hot and flowing.

The process i used was almost identical to this one.

https://www.youtube.com/watch?v=ws36A3vjNYs

I did about a dozen boards at a time. Much more than that and the pick and place becomes tedious. It really was fun to see all the components shuffle about and line themselves up neatly. Was almost like magic. Made all the time doing the pick and place worth it.

[MPaulHolmes]

Ya, I got distracted by thanksgiving stuff and my job. I just want to test the serial code. Then I'll ship them both. Let's put a deadline of next Friday. That will pressure me to get in gear so, I'll find out next week how much it will be to ship the cheapest way possible.

[e*clipse]

Originally Posted by Astro

e*clipse, i used a hot air soldering station to do all my BMS modules and it made the process quite easy. If there were any issues like a resistor standing up due to surface tension (happens occasionally, depends on amount of paste you use) then it was simple to just push it back down with tweezers while the solder paste was still hot and flowing.

The process i used was almost identical to this one.

I did about a dozen boards at a time. Much more than that and the pick and place becomes tedious. It really was fun to see all the components shuffle about and line themselves up neatly. Was almost like magic. Made all the time doing the pick and place worth it.

COOL! Thank you Astro.

That works better than my toaster-oven technique in that desoldering is also easy. Wow. That video speaks volumes.

- E*clipse

[Astro]

It worked really well for me.

Not a single component failure that i can remember in over 50 cell top BMS modules and 3 master modules.

Also now i have a handy heat gun on my workbench for things like heatshrink and plastic bending.
I even used it to test the temperature sensor on each of the cell top modules.
I noticed in the video he "tidied" up the solder paste. I found that was unnecessary unless you had really piled on the paste. Even if the paste hangs off the pad a little, surface tension will bring it right back onto the pad when the paste melts.
After doing a few modules you get the hang of the paste syringe and excess like he had doesn't happen.

I was initially worried that i would over heat the components. But you quickly get to know how rapidly the heat gun melts the paste and you move on as soon as the paste melts fully.
Watching a few videos of toaster ovens and their temperature curves, they heat the components up a lot slower and cool them down a lot slower.
So the heat gun approach may cause more thermal stress as the outside of the component will heat up much more rapidly than the inside of the component.
But that may be a good thing as it is the solder paste we want to heat up not the component innards.

All i can say is it works perfectly for me.

[MPaulHolmes]

I really need to get one of those. How about soldering those 64pin tqfp chips with the very fine pitch? How do you add the solder paste? Do you think a credit card, and then trust that the tension will clean up the bridges? I had wanted to keep the boards solderable by hand for a semi average joe, but adding a boost stage requires a 4th pwm pair which pushes me out of thru hole microcontrollers. I could use a separate micro for the boost pwm pair. But seeing how easy the heat gun is, maybe I should do populated boards? It sort of opens me up to law suits, or so I have been told by an insurance company.