high power/high speed BLDC controller build

[johnrobholmes]

Hot damn I got lucky and it ran the first time! I couldn't follow the wiring in the motor fully, so I was guessing on which phase was which. Ye haw!! Double checked it on a sensor only controller, smooth as butter.

 

[gip_mad]

Cool!

 

[johnrobholmes]

sensors hot glued in place. Endbell mags overhang stator by 6mm so that they get triggered.

 

[johnrobholmes]

oddball question here. If the stator was skewed, would the hall sensors need to be placed at the average "front" side of the tooth? Right now it is smack in between two teeth. With a skewed stator this would cause a timing change, so my guess is that the hall sensor would need to be placed at the front of the proper tooth at the middle point of the stator height.

 

[dirty_d]

you might wanna try moving the sensors over one pole to see if it runs with lower amp draw. i had my sensors between the wrong poles, it still ran just with a large timing advance. im pretty sure thats why it was so loud.

 

[johnrobholmes]

I got em right, I managed to follow the wiring enough to see which slot was which path. Not the particular motor I used, but this is how they are wound.

 

[lawsonuw]

Johnrobholmes: If you could color an end on picture of your motor to show the phases in relation to where the hall sensors are that'd be grand! I got's all kinds 'o book learning, but I still learn best from pictures.

Marty,

P.S. the BattleBot guys would love this! BLDC works great for weapons, hall sensors would allow using 'em for drive too.

 

[johnrobholmes]

Here you go.


For clockwise rotation looking at the stator as show, Hall 1 would correspond to red, Hall 2 to Green, and Hall 3 to the purpleish blue. For counterclockwise Hall 1 triggers green, etc. Trigger sequence is 1,3,2 for clockwise and 1,2,3 for counter. .


Since it is terminated Delta it isn't quite so simple, as the all three pole groups are being triggered for each phase excitation. The concept works without too much thought however. When terminated Wye it is much easier to understand.

 

[lawsonuw]

THANKS! *save* one more useful picture in my archive.

oh, by the way you can sand down the case of your hall sensors if you like. Most of the bulk is just plastic. The actual silicon chip will be very small and roughly in the center. The data sheet might even have dimensions stating exactly where the sensor is in the case. (may even show the shape of the lead frame)

Marty

 

[Lanchon]

proper care of your hall sensors...

Guidelines for Designing Subassemblies Using Hall-Effect Devices
http://www.allegromicro.com/en/Products/Design/an/an277031.pdf

 

[daveinsingapore]

this is the driver board i made for it, if anyone wants the schematic or pcb layout files just ask.

hey dirty_d...have read all your posting for this bldc controller and congratulate you big time.....saw your vids on youtube the week they came out...and was so glad to see someone was not just using the hobby shop R/C units or the japanese crystalite or golden models..they have so many crazy unreliable designs..any way big time thanks to you and your skills....I come with a RC background and have had enuf small ESC's burn out on bigger BLDC motors and want to move on to bigger and better things.
I totally steered clear of brushed motors after having been there done that some years ago...now I am looking at bigger DIY BLDC motors and I too need a controller that can perform and yours looks like it can. I am not good at electronic design but I understand what has to happen, and yours does work...as for the limits of voltage and current handling...I understand that all depends on what we fix to your present controller....I will be using M1 batteries ex DeWalt on my projects...the 36volt pack models which are actually 33v....and have three projects I am going to work on one at a time...

Mean while..you have shown the layout of the main controller, and a view of your first board hard wired....could you by any chance pass on the actual graphics for the circuit board etch pattern...and yeah like you I learnt years ago to do the 'cooking' of the circuit boards outside...away from the wifes kitchen.....I use a old gas bbq cooker with an old pot that no one else dares use accept me......don't blame the wife though....the kids go crazy when we cook normal food in the kitchen that smell the least bit healthy, not to mention me cooking my circuit boards...any way we all can laugh at that lot....

By the way one of my pet projects I have on the drawing board is a upsized kick scooter....longer than a standard GoPed- KnowPed model, but with suspension both ends and retaining the hard rubber tyres they use and a longer deck....all alloy, with 38mm alloy thick wall tubing for the dual rails, with alloy plate top and bottom to house the controller and batteries and with the rear wheel looking like a solid wheel when infact it will have a hub motor....basically a bldc with the outer bell being the rim of the wheel....any way we here in singapore have this crazy 200w max law for power assisted bicycles and stuff...with a 25km max rule....but no one said anything about powered kick scooters....of course by hiding all the motor and controller and batteries within the chassis of the beast and still being able to fold down the handle and taking it on board the local MRT...(mass rapid transit)..the local electric train system, I hope to enjoy the best of both worlds - Zapping along at what ever speed I end up with over 25km, when not on the train...and hearing the whir of those big massive motors when on these electric trains....all in all a rather buzzing experience....any way what I need first is a decent motor controller that will not go bang at the wrong time.....also could you please indicate what size your circuit board was for this controller....I do hope your sandaled foot recovered from that beating those badly funtioning drivers got a couple of weeks ago...lol

ciao for now....daveinsingapore

 

[dirty_d]

yea sure heres all the schematic stuff and pcb layouts, they're for geda, its a free program for linux for electronics design, it might be for windows too, or the files might be able to be imported to whatever program you use. im pretty sure theres nothing wrong with the circuit, i forgot to set the hardware current limit, and i had no software current limit either, i was just doing a test with a fixed duty cycle, i started at like 5% then after a few seconds had it go to 10% then 20%, i figured it would be fine since there was no load, but i think the low resistance combined with the low inductance let enough current flow right when switching to a higher duty cycle to instantly fry the fets. i dunno when im going to rebuild it, the biggest pain in the ass is coming up with the design for mounting the fets so the traces or whatever can carry 100+ amps without heating up much.

you can extract the archive with winrar, a lot of the stuff in the main board schematic is unneccissary if youre goign to use hall sensors so you cna save some money and time by taking it out, or just leave it as is and dont install the components.
View attachment bmc.tar.gz