Compact Field Oriented Controller, ASI + Grin, limited run

[justin_le]

So what is the absolute max power of this little controller once potted? Is it any higher or lower?

I don't think that the potting is either here or there in terms of the power capability. Pretty much the entire thermal path is through the aluminum heatsinks, so it's the heat capacity of that which will determine the time it takes before the controller goes into thermal rollback, and it's the ability to shed heat from that (via passing airflow or attachment to a larger metal surface like the bike frame) which will determine the steady state continuous phase current output at thermal rollback.

Both figures could be increased significantly by simply bolting the controller to a larger finned aluminum heatsink block, and we're trying to make it easy for people to do that if they are running high phase amps all the time. We will at some point run some proper lab tests in order to quantify the operating envelope under different conditions at different wind speeds, but it's an elaborate and time consuming set of experiments to run.

For my own usage with this first prototype, riding ~40 kph with power draws from 300-1200 watts depending on the grade hill it's only ever gotten just warm to the touch.

 

[Jason3]

Hi all,

More BAC500+ fun I was playing around with a low inductance RC inrunner, and now I've got error 14 - 'Current sensor calibration'. Is that something I can sort out, or is it likely to need repair?

Also, I think I really have cooked the USB-TTL cable this time. It doesn't work with the Cycle satiator any more, and I get a message saying a USB device is drawing too much current and the ports have been disabled until it's unplugged. Can I use the regular USB-TTL cable with the Satiator as well as the BAC500+ or will I need to get the protected one for the satiator?

Many thanks!

Jason

 

[cycborg]

I notice that the online store listing for the BAC 500 now includes "ETA: June 29, 2015". Are you doing another run of this unit, or is this actually for the BAC 800?

 

[CKs]

Hi Justin,
Set bit 1=0(Default) in Features, run the motor and then connect cruise port with low level signal(GND), but the Cruise function doesn't work and the motor can't hold the current speed;
do u know how to set this function?
tks.

 

[tightbox]

Did the new batch arrive?

 

[justin_le]

I notice that the online store listing for the BAC 500 now includes "ETA: June 29, 2015". Are you doing another run of this unit, or is this actually for the BAC 800?

It's actually the BAC800 units. Here's the long update.

We got all the PCB's from ASI about a month ago but it's taken quite a while to sort out how to do the remaining manufacturing with any reasonable efficiency. The part that went really nicely was creating a new aluminum master mold. It's always a challenge with potting operations like this to have things pour cleanly without leakage, so we included a number of locating pins around the perimeter to hold the silicone tight to the heatsink. This turned out way better than the mold cast from the 3D printer prototype, and man does the brushed aluminum finish ever look good. So if we do get an enclosure, there's good odds it would be brushed aluminum, even if it's not quite the best of radiative heat dissipation
View attachment 4

The other detail was that previously we had most of our signal wires hacked onto the tiny and tightly spaced pads that were originally intended by ASI for a 24pin JST connector, which was a time consuming and messy job. So we designed up a perpendicular daughterboard that had larger and more appropriate pads for soldering the wire harness, our precision 1% 1mOhm CA shunt, and also additional resistors, zeners, and polyfuses as protection circuitry for all of the signal wires. Our hope is to make it so that any errant connection or wiring mishap can't permanently damage something on the controller board. For instance shorting V+ to any of the signal lines, static discharges etc. The large yellow square is a 2A polyfuse for the V+ output from the key switch to the CA, so that if this if ever shorted you won't have full battery currents going through the small lead wires or vaporizing traces.



The first batch of daughterboards here addressed 90% of our needs, but after assembling a few with it we decided to make more changes and are expecting an updated batch of PCBs to arrive next week, so that's what we are currently waiting on. But the few that we did pour turned out really beautiful. Here it is just before going into the mold.



And here is the result after an overnight cure, like holding a newborn baby in your hands



Looks good from the backside too,


Right now I would say best case we'll be ready to pump them out in 2 weeks time.

 

[justin_le]

Also, I think I really have cooked the USB-TTL cable this time. It doesn't work with the Cycle satiator any more, and I get a message saying a USB device is drawing too much current and the ports have been disabled until it's unplugged. Can I use the regular USB-TTL cable with the Satiator as well as the BAC500+ or will I need to get the protected one for the satiator?

You can use a normal one, but you may need to be careful about the sequence of plugging things in if you don't have the relative ground potentials established. For instance, if you run the BAC500+ from a switching power supply with a floating output, it could well be at like 50+ volts from ground with relatively high capacitance and as you plug this into the TRS jack it will discharge through the signal line. Best is to plug the TRS cable into the controller first, and then connect the USB to the computer (which is typically grounded), and then finally turn on the power supply.

-Justin

 

[nieles]

Those clear resin molds are pure awesomeness..

I like my electronics on display

 

[ambroseliao]

That is just beautiful! Ebike pron!

 

[nicobie]

WOW! I'm impressed. love the clear potting. Think you will be keeping it?

 

[justin_le]

WOW! I'm impressed. love the clear potting. Think you will be keeping it?

Well the plan was to pour them in black, but if people really like it then we can very easily leave out the "add 2% dye to resin" step. Or add small amounts of translucent colours if you like the candy look? For our next pouring experiments we have a fairly thick layer of silicone conformal coating on the circruitboards in order to address the temperature coefficient concerns, which I expect will result in a more cloudy/foggy area around the PCB.

The only concern is the long term UV exposure on the resin without a dye containing UV inhibitors. We have some samples of this cured resin that we've left out in the full sunshine for the past couple months to see how they hold up in terms of discoloration which is often an issue, and it seems to have gotten a tad yellowish, but not much. It might be that a simple coat of UV Varnish on the finished part will keep them looking crystal clear.

-Justin

 

[amberwolf]

Just add a little yellow-orange dye to start with, including the UV inhibitor (if it's translucent), and then you can sell them all as FOCsil controllers, trapped in amber.

 

[will_newton]

Just sayin'.

 

[Jason3]

You can use a normal one, but you may need to be careful about the sequence of plugging things in if you don't have the relative ground potentials established. For instance, if you run the BAC500+ from a switching power supply with a floating output, it could well be at like 50+ volts from ground with relatively high capacitance and as you plug this into the TRS jack it will discharge through the signal line. Best is to plug the TRS cable into the controller first, and then connect the USB to the computer (which is typically grounded), and then finally turn on the power supply.

-Justin

Great, thank you - that's good to know.

I'll take a clear BAC800 thanks. They look fantastic

Jason

 

[amberwolf]

And you can sell any failed clear ones as geek jewelry, quite possibly for as much as a working one, to the right people.

 

[Arlo1]

What would be cool is a coating that changes different colors based on temp....

If it was a clear mold with this that would be total amazeballs

I love the clear potting. Great job Justin.

 

[ambroseliao]

I'll take a clear one too. Just curious, how much does it weigh and what are the dimensions?

Also, does it work with motors with more than 3 phases? （Specifically, 5 or 7 phase motors?)

 

[speedmd]

Clear acrylic or polycarbonate shell with the clear potting would be a egeek home run! :lol: A Must have! To Arlos point, you could add a temperature color strip thermometer with the clear shell as a passive temperature indicator.

 

[nicobie]

Clear acrylic or polycarbonate shell with the clear potting would be a egeek home run! :lol: A Must have! To Arlos point, you could add a temperature color strip thermometer with the clear shell as a passive temperature indicator.

Now that's clever! And wouldn't cost zip.

 

[fechter]

I like the clear too. If a part burns up, you'll be able to see it. LEDs on the board are cool too.
That's looking really nice.

It would be good to find some finned heat sink extrusion that has the right dimensions that could be screwed on. This would be a good thing in lots of installs where you don't have a decent chunk of frame to use as a sink.
Coming up with a 'universal' tubular clamp that passes heat would be nice too. I can't really think of a simple way to make one size fits all. Fixed size pieces made in the most common diameters would be fine if you have the right sizes.

 

[999zip999]

" Now that's clever ! and wouldn't cost zip "
Cool where do I sign up ?

 

[justin_le]

Just sayin'.

I know, I was thinking that not quite enough time has passed since the iMac intro for the "hi-technicolor' translucent color scheme to be back in vogue. But we'll offer this dyed option as well for those who do want to colour coordinate with their bikes, and the circuitry still shows through quite well. In the meantime though I've been thoroughly impressed with the response on the clear device. I cast it this way just as a means to facilitate our own QC process for easily checking for trapped air pockets etc. not expecting it to turn out quite nice as a final product. But you guys have spoken.

Just add a little yellow-orange dye to start with, including the UV inhibitor (if it's translucent), and then you can sell them all as FOCsil controllers, trapped in amber.

Yes! Name ideas are another things we need to sort out, since I want to call this something to differentiate it from the stock BAC800 from ASI to avoid item confusion, and we need to sort that sooner rather than later in order to CNC engrave it on the master mold so that it shows up in the castings.

I was teasing with the idea of calling it the FOC Yeah 800, but I dunno if the number of people who appreciate the edgy humor will be sufficient to offset those who don't. Thoughts?
Others in contention in include Cycle Coordinator (parallels our other naming schemes a bit), Phase Runner (alludes to FOC phase current control capabilities), FOC-sy, or some similar spelling that sounds like "Foxy", alluding to the small slender size. Anyone with a great name suggestion based on what you've seen that hints at the controller's function/capabilities will of course be eligible for a free device if we chose it. So fire away if you've got a creative mind for word-smithing.

For those asking about signing up to get one etc., I think I'll probably stick to the policy of only taking orders once they are ready to sell rather than doing pre-order stuff, and will keep people informed on this thread when that gets close.

 

[liveforphysics]

Flux-Phidias

 

[amberwolf]

I was teasing with the idea of calling it the FOC Yeah 800, but I dunno if the number of people who appreciate the edgy humor will be sufficient to offset those who don't. Thoughts?

I'm sure *somebody* would get upset about it, and some might get excited, but I dunno if it would affect a purchase decision one way or another for most.

Cycle Coordinator

Meh... Cycle FOCuser? Nah. Dunno. Doesnt' have any "grab".

(plus, to me "coordinator" would be more for a central brain that controls *everything* on the bike, something like the system I was trying to come up with back in my early ebike days (which you guys could do easily, but not sure there's a market anyway)).

Phase Runner

Sounds neat enough to me (and makes me think of Blade Runner, which is always a plus ) and I think it would sound "techy" enough to be good for marketing.

FOC-sy, or some similar spelling that sounds like "Foxy", alluding to the small slender size.

I don't think people are going to "get" that one.

Anyone with a great name suggestion based on what you've seen that hints at the controller's function/capabilities will of course be eligible for a free device if we chose it. So fire away if you've got a creative mind for word-smithing.

I think I may have used up all my brain cells on the first one I tossed out there :lol: but with that kinda prize I'll keep the hair burning.

Flux-Phidias

That's another I don't think most people will get at least here in the USA (too few people know anything about historical culture or art in their own culture, much less ones across an ocean from here).

 

[bowlofsalad]

FOCQ!

I'm sure *somebody* would get upset about it

www.youtube.com/watch?v=amKyA2PrSu4#t=8s