New sensorless controller: Can I leave the hall sensors unwired?

[Olmen]

The headline pretty much says it all. Recently, my beautiful baby ebike was vandalised in the cold Helsinki night. The thugs ripped of the controllers, throttle and wires. Left the motor though... idiot thugs.

So now I ordered a new controller which is "sensorless". This is the one that goldenmotor is selling. Now when I'm rewiring, I started to figure - do I really need to wire those hall sensors at all? The controller is sensorless, right? Does it even need to be connected to the hall sensors?

The reason I ask is because 1) I'm having a hard time fitting all the wires through the little whole in the axle, 2) I'm lazy and don't want to solder all those tiny little wires and 3) I think one of the sensors is done for anyways and needs to be replaced (what a hazzle!).

Are there any drawbacks to running without hall sensors?

[MonkeyMagic]

Its funny I just posted a similar reply in another post.

I was wondering if there was any efficiency difference, meaning battery consumption. I would assume it would be a small difference.

Another thing I was wondering, was if you have a sensorless controller - then why does it have the hall sensor cables?
If it does it either does both, or must need them. I am thinking the latter.

Do you have a wiring diagram for the controller?

[Olmen]

It's like you read my mind, friend! Well the controller I have is the one that is sold on goldenmotors.com so that's also where I got the wiring diagram from (http://goldenmotor.com/e-Bike-DIY/Cruise%20Controller%20Wiring%20Diagram.pdf). One would assume think that sensors would add some efficiency gain compared to sensorless systems - why would you otherwise use the sensors. But I assume once the sensorless controller finds the right phase or positions of the motor it would work just as efficiently (if not more so!). I guess one drawback with having no sensors is that  the engine might have difficulties in starting up in certain positions. But I haven't tried anything yet so this is all guesswork on my part.

I'll try to have everything hooked up as soon as I can and I'll post the results here.

Great forum by the way. Two thumbs up!!

[MonkeyMagic]

Hey Olmen

Okay so I think I get it now, I thought you had a controller without hall sensor. That's just the GM 'cruise' controller.

So if your hub motor (be that brushless), is a sensorless hub motor, it should just have 3 thick wires coming from it (phase wires)
You hook it up to Mb Mc Ma of the controller and if the controller does not see the sensors it will be in sensorless mode.

So yes, I guess you can be lazy and not solder then hehe

[Olmen]

Well I hooked up the GM "magic"-controller to the motor and left the hall sensors unwired. But the controller wont to into sensorless mode. It doesn't give any power to the motor at all and it doesn't "beep twice for sensorless mode" either.

What are your thoughts? I can't figure out why the controller wont go into sensorless mode. There's no option for that in the programming interface either. Am I missing something? Should I just hook up those hall sensors (awful lot of work :-( or is there something else I could try?

I've been thinking about shorting the pins for the hall sensors on the controller with some sort of jumper. Is this wise/unwise?

Any help much appreciated!

[MonkeyMagic]

Did you try spinning the wheel?

I'll try and dig up some references. Do a search for sensorless in the search bar here there will be some guff

[Olmen]

This is puzzling me to bits.

I put the controller in 60 deg phase mode. I tried spinning the wheel and presto - of it flew like never before. After fiddling with the wires and connectors for a while it went dead and now I can't get it to work again.

When I plug the voltmeter in the battery + phase wires and turn the wheel by hand I do get potential. Doesn't this mean that the connection is solid between controller and motor?

I must say that I find the connectors for the battery and phase wires a bit annoying. I'm using some old anderson connectors now but maybe there are some better alternatives. What are you guys using=

[Olmen]

Shouldn't there be some voltage in the leads to the throttle? Right now I'm getting nothing on the T1 and T2 terminals! It's like the controller isn't listening to the throttle at all :-/

[Bikemad]

Shouldn't there be some voltage in the leads to the throttle? Right now I'm getting nothing on the T1 and T2 terminals! It's like the controller isn't listening to the throttle at all :-/

You should have almost 5V between "T1" and "Z".

The voltage reading between "T2" and "Z" should vary between 1 and 4 Volts according to the throttle position.

If you are not getting any voltage readings, try disconnecting the throttle connector (and the PAS if fitted) and then recheck the voltage between "T1" and "Z" again.

If there is still no voltage reading, I'm guessing you might have somehow shorted out (or overloaded) the +5V supply when you were "fiddling with the wires and connectors"

Alan
 

[Olmen]

Progress! As I suspected those anderson connectors where the culprits. The controller didn't get juice from the battery - hence there was no voltage on the control interface.

I now have new connectors which are very solid. But a new problem has arisen: The motor will kind of activate, then stutter and then stop with a jerk. I can hear a electrical hissing sound from inside the motor. I tried spinning it manually but as soon as I hit the throttle the wheel will jerk to a stop. I also tried connecting the phase wires in different order but that doesn't seem to be the problem either. I'm lost for words.... again.

EDIT: Seems that out of the three phase terminals on the controller - only the middle one (Blue) is giving any voltage when I hit the throttle. It gives about 10 V when I hit the throttle, then holds at about 5-6V for a few seconds and then cuts out completely. No beeps from the controller. Maybe I should hook it up to a small speaker to hear the beeps??