hejo said:
Are there any news about the new tiny controller?
How does it perform?
I'm quite pleased that so far the little controller has been doing just fine. I still get a bit nervous drawing a continuous 30A on long ascents, but the worst of those are over and right now on the prairies well it's pretty easy going for all systems involved.
BillVon said:
Sounds like a great little controller! Have you considered adding phase advance? With phase advance I think you'd have a controller that could do anything.
Phase advance is really easy to do, but it doesn't make any improvement with the low commutation frequency ebike hub motors (unless you consider reducing the efficiency and increasing current draw an improvement). That's more something that comes into play with the 10,000+ rpm RC motors.
Mitch said:
It would be nice (IMO) if there were (like the Heinzmann) Overtemperature protection for the motor as well as the controller. Users could mount a temperature sensor on the motor and there could be a plug for it on the controller plus the ability to adjust the settings.
I've thought about that, but it's not so easy to retrofit a temperature sensor inside a hub motor, since the wiring needs to go through the axle and generally there isn't room for anything more beyond the phase and hall leads that already occupy that space. This is especially true with the common practice now of having the cable run through a hollow in the center of the axle, rather than a larger slot on the slide like Crystalyte.
With proper motor current limiting that this controller has, there really shouldn't be any need to have a temperature sensor inside the hub. Both the controller and motor are going to be heated by the same currents, and a temperature rollback on the controller overheating will also limit the motor heating. As the hub motors have considerably more thermal mass than the controllers, you are not likely to ever run into a situation where the motor is overheating and the controller isn't.
The heinzmann only has a bimetalic type of temperature switch, and the controller just cuts out when this is switched.
Two more controller related questions (if someone other than Justin knows the answers and wants to reply please do so):
Does Sensorless (#7) mean this would work with RC motors?
It means that it will work with brushless motors that don't have hall sensors. However, I did not design it for motors with really high commutation frequencies like RC motors. I haven't tested the limits yet, but I'd say an upper limit on the commutation frequency would be about 500Hz for sensorless operation. Take that number, multiply by 60, and divide by the number of poles in your motor to get an RPM value.
I don't understand the implications of Current Throttle (#6). If someone would explain this I would appreciate it.
In a typical ebike controller right now, if you apply the throttle part way from a stop, you'll get the full current limit of the controller flowing from the battery at first, then as you accellerate this current will go down until you hit your partial throttle cruising speed. If you then pedal the bike, the current will go down further, to zero amps, unless you press the throttle further.
With a current throttle, if you applied it part way, the current that flows from the battery pack would be in direct proportion to how far you are pressing the throttle, regardless of your speed, until you are going fast enough that the current is back-emf limited.
Chances to launch it ? Price? I want two of them asap
Can you give us a ball park estimate of when it might be available?
Just to clarify, the controller is still just a pet project of mine, so don't anyone hold their breath for this to show up at an ebike shop near you. There aren't any plans at all to manufacture controllers for resale at this point, though that may change in the future.
-Justin