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Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 4:10pm
by zombiess
mini-lebowski.jpg
The above pic is 2 boards that will be separated and stacked after they are made. Made them all on one board for fabrication, it's easier to solder.

I would like to see more people trying out Lebowskis controller and helping him develop more features. The hard part about building a controller from scratch is you have to design EVERYTHING and it's a pretty daunting task. I believe with some simple kits we can get more people up and running on these controllers.

I have been working on a pretty small version of a Lebowski brain board for his latest chip version. The completed setup is 2 boards that stack with headers and is 3" long by 1.5" wide and I'm guessing about 0.75" thick. I incorporated my own error handling / detection system using a PIC 18F1320 if you so desire, it can also be bypassed by a jumper. The construction is a combination of SMD and through hole, but I made as many components SMD as possible. The board accepts the standard 40 pin DIP package he uses to allow for easy swapping of chips as he upgrades his code.

I have already designed and am using a larger version of this board, but this new one is about 1/5th the size of it. There are no current sensors on board for maximum flexibility and size.

If there is enough interest, I can have the PCBs pre fabricated with all the components and sockets for the chips which are flashed, but I don't know exactly how many people we would need to make this an affordable option since it would a low volume run. I know many are concerned about working with SMD components because I myself was until I tried about 6 months ago and not it's my preferred method of construction because I find it's easier than through hole in many cases, the opposite of what I expected!

Post up if you have interest. If we don't have much interest I can supply all the parts as a kit.

I'm also thinking about designing a small power stage for a complete controller setup that fits into a pretty small box. It would probably be 12 TO-247 100/150V MOSFETs and be good for 200A phase which is enough to make your bike pretty darn fun. You also get really cool features like variable regen!

Re: Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 6:58pm
by ARod1993
zombiess wrote:I would like to see more people trying out Lebowskis controller and helping him develop more features. The hard part about building a controller from scratch is you have to design EVERYTHING and it's a pretty daunting task. I believe with some simple kits we can get more people up and running on these controllers.

I have been working on a pretty small version of a Lebowski brain board for his latest chip version. The completed setup is 2 boards that stack with headers and is 3" long by 1.5" wide and I'm guessing about 0.75" thick. I incorporated my own error handling / detection system using a PIC 18F1320 if you so desire, it can also be bypassed by a jumper. The construction is a combination of SMD and through hole, but I made as many components SMD as possible. The board accepts the standard 40 pin DIP package he uses to allow for easy swapping of chips as he upgrades his code.

I have already designed and am using a larger version of this board, but this new one is about 1/5th the size of it. There are no current sensors on board for maximum flexibility and size.

If there is enough interest, I can have the PCBs pre fabricated with all the components and sockets for the chips which are flashed, but I don't know exactly how many people we would need to make this an affordable option since it would a low volume run. I know many are concerned about working with SMD components because I myself was until I tried about 6 months ago and not it's my preferred method of construction because I find it's easier than through hole in many cases, the opposite of what I expected!

Post up if you have interest. If we don't have much interest I can supply all the parts as a kit.

I'm also thinking about designing a small power stage for a complete controller setup that fits into a pretty small box. It would probably be 12 TO-247 100/150V MOSFETs and be good for 200A phase which is enough to make your bike pretty darn fun. You also get really cool features like variable regen!
That would be pretty awesome; I've been interested in designing my own field-oriented motor controller for a while but have never quite been able to make sense of the necessary control algorithms; I'd love to buy a Lebowski box from you, especially if you're pairing that up with a TO-247 power stage that can pull 200A phase. I've got a couple of C80100s (at what I believe is 130KV), as well as a hardtail mountain bike and a little 500W DC brushed escooter that I'm looking to soup up, and what you're talking about would be great!

Re: Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 7:46pm
by liveforphysics
Yes please. :-)

One with a footprint for this amazing tiny $15 chip please. :-)

http://ixapps.ixys.com/DataSheet/MTI145WX100GD.pdf

It would be like the power of a TO220 12-fet, but in a package perhaps 1/8th the size, and with the unbeatable control strategy Lebowski's brain uses.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 8:14pm
by amberwolf
Interested, definitely, but it would have to be in a pre-assembled version at least for the SMT parts, cuz I just can't see or manipulate well enough anymore to do that stuff reliably. :( (I actually have to send my CAv3 to Justin to get it fixed instead of doing it myself, for that reason).

It'd also greatly depend on the cost, for me. (and whether or not I could sort of slap the brain onto the power stage of an existing controller like a "common" 12-FET or 18-FET and have it work, or if I'd have to buy someone else's power stage, too).

Re: Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 8:18pm
by zombiess
LFP, let me know about access to those, I am interested in that package for making a small mid power controller. I'm finding that 60-85V packs are usually all one needs to achieve good speeds. The top speed game is fun to play but it's more of a novelty than useful for most. For me 40mph is plenty when commuting.

I hope someone comes out with a nice compact 300-600A sensor like the 200A Allegro units.

These bridges would also be nice to play with since I'm learning TI's C2000 DSPs right now (these micros are really impressive, I have a F28027 and a F283335) so I can do some work with Instapsin/motion control (I already have it working, but no throttle input yet).

Re: Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 8:23pm
by teslanv
Way beyond my skillset, but that looks awesome.
Would defintely be a buyer of a completed controller.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 8:40pm
by liveforphysics
zombiess wrote:LFP, let me know about access to those, I am interested in that package for making a small mid power controller.
I was quoted $15/ea in 1k qty. I can connect you to the right person to purchase them, I imagine in qty of like 100 pieces they will likely be ~$20/ea, which is a bargain for what it offers.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 8:51pm
by zombiess
teslanv wrote:Way beyond my skillset, but that looks awesome.
Would defintely be a buyer of a completed controller.
If there is enough interest I can contact a fab company to do a sample run after I build and test my prototype. I believe I could get the fab costs reasonable, even for just 10 of these, I'm guessing < $200ea since they would probably be hand assembled due to the low quantity. Even though $200 isn't cheap, that could include the driver and most of the power stage leaving some assembly required by the end user such as choosing their own MOSFETs.

I like the IXYS chip Luke posted if it can be acquired, but I also like the idea of a 12 FET TO-247 power stage. I can tweak my gate driver layout to work with a specific package, lay the MOSFETs flat like I have in my last design and the entire controller without enclosure would only be around 1.25" thick by 3.5" wide (length would be determined by parallel FETs). Then all we would need is some 0.25" aluminum flat bar and have it drilled / tapped which shouldn't have too high of a cost.

I've been dreaming about designing a and manufacturing a full controller, but I don't know if there is a big market for a 24-80V high end 3 phase BLDC FOC controller (could be used for anything since it covers a massive range). Right now I want to help more people access Lebowski's work so he has more motivation and feed back. He's the only controller brain designer we have access to that accepts feature requests. I feel I'm pretty solid on the gate driver / power stage design now, especially after ripping apart many commercial setups and seeing what they do less than optimal, but still have functioning controllers.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 12 2014 9:11pm
by zombiess
liveforphysics wrote:
zombiess wrote:LFP, let me know about access to those, I am interested in that package for making a small mid power controller.
I was quoted $15/ea in 1k qty. I can connect you to the right person to purchase them, I imagine in qty of like 100 pieces they will likely be ~$20/ea, which is a bargain for what it offers.
$15 each is a good deal, but I can't see buying 100 of these unless I decided to design a high end small controller power stage where the compactness of this would really shine. Might be able to do a real 50A continuous +100A burst (fan cooled and probably limited by the high Tjc which is way better than the SMD stuff R/C controllers use) power stage the same size as a 6 FET Xie Chang controller, but with all the good features.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 1:08am
by Futterama
zombiess, exactly how much is included on these boards you posted? Everything from Lebowski's schematic and then some?

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 4:02am
by liveforphysics
zombiess wrote:
liveforphysics wrote:
zombiess wrote:LFP, let me know about access to those, I am interested in that package for making a small mid power controller.
I was quoted $15/ea in 1k qty. I can connect you to the right person to purchase them, I imagine in qty of like 100 pieces they will likely be ~$20/ea, which is a bargain for what it offers.
$15 each is a good deal, but I can't see buying 100 of these unless I decided to design a high end small controller power stage where the compactness of this would really shine. Might be able to do a real 50A continuous +100A burst (fan cooled and probably limited by the high Tjc which is way better than the SMD stuff R/C controllers use) power stage the same size as a 6 FET Xie Chang controller, but with all the good features.

Your assessment of it's real performance (thermal being the bottleneck) is very close to my own, and I was delighted by those values for something that could be RC controller sized provided it had a fan on it's heatsink, because this heatsink actually had an already isolated extremely direct thermal path that is flat and all in one easy to heatsink plane.

Remember, the topology for growing extremely high power isn't in making greater and greater phase currents being controlled at one switching stage, that's the least effective use of parts with respect to sharing the currents evenly between components used in the power stage. You divide it into individually current controlled stages, and sum there outputs, ideally combining closer to the motor for inductance for each individually current controlling stage to use for regulating it's contribution to the total phase current. I think this chip makes an ideal platform for doing these distributed current control concepts Lebowski was talking about many months ago, but I didn't see the beauty in the concept as it relates to unlimited motor phase current potential until recently. Want to drive 1,000A burst phase current into some super difficult low resistance low inductance load? You only need 10 of these tiny controllers setup to operate as a distributed controller and each having it's own individual current control system, and the sums of the current are what the motor winding gets.

It will either be this method, or going to 9phase or 12phase or whatever for motors for achieving things like top-fuel dragster level performance for electrics, but it's equally good for hotroding bicycles.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 8:41am
by speedmd
I can not resist taking a board and giving this a try.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 9:00am
by Nuts&Volts
I would be interested in a board or two. I can't solder SMD, but could pay a friend to if you only provide kits/boards. I have a Zero ZF75-5 and 75-7 motor that I could test it with. I do a lot of work with electric motorcycles and would be playing around with it in that package.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 9:51am
by Icewrench
Yes I would be in. Access to a brain board and a kit for a power stage would be real good.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 10:42am
by Thud
for sure here too...

what does it take to do SMT efficiently?
Ive seen the hot air pencil torch for repair work.....positioning parts may tax the old eyeballs....& paste solder in a hypo needle set up?


I have a dozen or so e-crazyman controller sets I have built up without problem's from keywin.( 6-12 & 18 fet)

on a scale of 1-10 how much more difficult is smt over thru hole assembly...either way it would bee a cool set up to try.
I can see a long info thread about trouble shooting & testing.

thx for the effort Z.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 11:47am
by cal3thousand
Yeah, I'm interested in a board as well. It might be pushing my comfort zone, especially with the SMD parts. But I trust your advice on the ease of SMD and would like to see more of this type of development on ES.

The small package, FOC, and power handling would be great!

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 12:39pm
by dbaker
I'm in. Assembled would be best since I don't have surface mount tools.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 3:07pm
by Futterama
I can't see if there are any components smaller than 0805, but if that's the smallest, surface mount tools would only include thin solder wire like 0.5mm, a pair of stainless tweezers and a soldering iron with a 1mm tip.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 3:30pm
by zombiess
Do not be afraid of smd as I was for many years. Its how everything is done now. Hand soldering 0805 components is much easier than you realize, you need very thin solder a $60-100 temp controlled soldering iron and a good set of tweezers. That's how I started then 2 months later I purchased an aoyue brand hot air/soldering station since I decided I SMD is now my preferred method.

I find it faster than through hole soldering in some cases.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 3:55pm
by dbaker
Convinced.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 4:30pm
by zombiess
I'm going a little off topic here, but it's good info for anyone seriously interested in DIY.

For anyone interested in making the jump from through hole to SMD, look at the Aoyue 968 station. It's Hakko tip compatible (comes with a many types of tips) and uses a diaphragm pump for the hot air station. The soldering iron is not as good as my Hakko 888D, but this station is plenty good for home lab work and does everything but vacuum desoldering. They even offer hot tweezers for it for $30 (got them but have not used them yet since I like the air).

Buy the thinnest solder you can get your hands on, that's one of the biggest tricks to working with these small components. The other trick is to use a chisel tip on the iron, not a needle point, it's counter intuitive until you actually try soldering SMD. I can drag solder (go to you tube and search drag soldering) a SOIC chip much faster than soldering the same DIP package and my finish looks much better.

A huge advantage of SMD construction for this type of work is that most of the traces are run on the top copper layer leaving the bottom layer free for a contiguous ground plane which helps reduce the evil noise, something there is plenty of in a high power controller.

There is enough information on this forum for a serious DIYer to build an advanced 500A controller for about $1000 including the needed tools to assemble. If I manage to continue having things go my way with this design, I can start offering partial kits because controllers can be somewhat modular.

Lebowski has suggested I design a 3rd board based off his 25-150v input SMPS that can supply +15 and +5v. I think that's a good idea and eliminates the power supply issues since everything I am designing is using isolated supplies.

Re: Would you like a very small Lebowski brain board?

Posted: Jun 13 2014 4:50pm
by cal3thousand
zombiess wrote: I think that's a good idea and eliminates the power supply issues since everything I am designing is using isolated supplies.
I think that is absolutely genius

Re: Would you like a very small Lebowski brain board?

Posted: Jun 14 2014 3:46am
by Lebowski
If you're going to make a small power supply board, the one i have uses quite a bulky 1.5mH inductor. There are some good LTCxxxx chips from linear which will work with much smaller inductors. I thought about this option when designing my PCB, the problem was that at the time there was 150V input version...

Re: Would you like a very small Lebowski brain board?

Posted: Jun 14 2014 5:06am
by Skalabala
What else is needed? Driver stage with currant sensors and power/output stage?

Re: Would you like a very small Lebowski brain board?

Posted: Jun 14 2014 7:10am
by Tek
Make it reasonably priced and I will also be down. BTW what is max e-rpm?