KT Controller problems.

RossG

Pedelecer
Feb 12, 2019
195
174
I've fitted a KT controller & LCD 3 setup to my folding e-bike mainly because I wanted the throttle option. That works great as does the PAS however I can't get Torque to work. I've set P3 =1 and the motor a Bafang has a internal sensor which appears to be working from my tests. The connector has 9 wires and that's ok, so unless I've set something up wrong it looks like the controller might have a fault.
Anything else I can try ?
 

danielrlee

Esteemed Pedelecer
May 27, 2012
1,151
599
Westbury, Wiltshire
torquetech.co.uk
I've fitted a KT controller & LCD 3 setup to my folding e-bike mainly because I wanted the throttle option. That works great as does the PAS however I can't get Torque to work. I've set P3 =1 and the motor a Bafang has a internal sensor which appears to be working from my tests. The connector has 9 wires and that's ok, so unless I've set something up wrong it looks like the controller might have a fault.
Anything else I can try ?
What makes you think it's not working as it should?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
The controller doesn't act like a torque multiplier like Bosch or other central motors. Torque control means current control by means of PAS setting, each PAS setting has a differing current draw (which China call torque control). Approxiamtely PAS 1 gives about 13% of current , PAS 2 about 20%, PAS 3about 33%, PAS 4 about 50% and PAS 5 100%.
On level ground you should be able to feel the acceleration in each PAS level. If you timed acceleration over a selected short distance then you should see quicker times as you go up in each PAS level, the main advantage is hill climbing this is where you feel the current draw (torque control) the most.
For max current draw C5 value 10 gives max current.
 
Last edited:

RossG

Pedelecer
Feb 12, 2019
195
174
But surely I would see amps drawn on the LCD display wouldn't I ? It just reads zero regardless of PAS level set no matter how fast/slow I turn the crank.
At the moment I'm testing indoors so there's no stress on the motor but I can hear it's not turning.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,427
245
Basildon
You need to describe the problem in simple words because what you're saying doesn't make any sense. In post #1, you said that it's working with PAS, but inn post #4 you say that the motor doesn't turn. Try starting again from the beginning as if you're telling your mum what's wrong.
 

RossG

Pedelecer
Feb 12, 2019
195
174
There's so many things I wish I could still tell my mum but then I always remind myself, one day I will again.

Anyway back to bikes.....I wired up the controller & LCD with just the necessary for testing and rotating the throttle it worked out the box. Turning the crank cadence also worked ok, but when I set P3=1 for torque nothing, the motor doesn't fire up. I've checked all the wiring and tried disconnecting the throttle and PAS sensor in case of any conflicts but still nothing. So throttle and cadence work but not torque.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,427
245
Basildon
P3 swaps the controller power algorithm for only the pedal assist from speed control to power control. It has no affect on the throttle. P3=0 is speed control and p3 =1 is power control. T has nothing to do with torque, excet that you get max torque in all levels under speed control and stepped torque on the 5 levels under power control.

Check again what you've done, and confirm that it still works with p3=0.
 

RossG

Pedelecer
Feb 12, 2019
195
174
Right'o VFR, I'll plug everything back in again this afternoon and check settings are correct just to be absolutely sure and report back.
 

RossG

Pedelecer
Feb 12, 2019
195
174
OK so these are my findings. Set to P3=0 I have PAS at levels 1-5 and throttle works as normal.
Set to P3=1 PAS is still operational ? but at full speed, adjusting levels make no difference. I'm not confusing speed with torque as the motor kicks in at full power when the cranks are turned slowly a full rotation.
Incidentally PAS also works whether I turn the cranks forwards or backwards. I think that's what's known as an anomaly.
 

danielrlee

Esteemed Pedelecer
May 27, 2012
1,151
599
Westbury, Wiltshire
torquetech.co.uk
OK so these are my findings. Set to P3=0 I have PAS at levels 1-5 and throttle works as normal.
Set to P3=1 PAS is still operational ? but at full speed, adjusting levels make no difference. I'm not confusing speed with torque as the motor kicks in at full power when the cranks are turned slowly a full rotation.
Incidentally PAS also works whether I turn the cranks forwards or backwards. I think that's what's known as an anomaly.
You can only evaluate torque mode with the motor under load. Lifting the rear wheel in the air and applying just a little power will always make the motor spin at full speed.
 

RossG

Pedelecer
Feb 12, 2019
195
174
Hi Daniel, well yeah I did wonder that because I'm testing on a bike stand at the moment. So checked online and some videos on you tube demonstrating the different modes of drive show torque in action, bikes on work stands with no load applied. Of course not all systems are the same, maybe my bike needs a load applied to work correctly.
The PAS sensor has 12 magnets, not sure of the model it came with the bike.
 

danielrlee

Esteemed Pedelecer
May 27, 2012
1,151
599
Westbury, Wiltshire
torquetech.co.uk
A controller powering a motor in 'torque' or 'current' mode will always spin it at full speed without a load on the motor. Any video demonstrating otherwise is showing a 'speed' controller.

To solve your backwards peddling PAS issue, tty setting custom parameter C1 to '5'.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
7,275
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West Sx RH
You can test the current/torque on a stand by using throttle and using the brake by nearly stopping the drive, keeping an eye on the watts on the LCD you will see each PAS level has a different W output.

With P3 set to speed mode you get max current/torque with each PAS level, each level will give an increase in speed. With P3 set to current/torque mode you get differnet current levels with each PAS level, each level will hold the same speed.
 
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RossG

Pedelecer
Feb 12, 2019
195
174
Thanks guys...all is now working correctly. Daniel you were right about the C1 setting, now working with forward peddling only. Torque also working as it should although I can only test on the road properly of course under load.
Thanks also to Neal & Vrf, all useful information stored for future reference.
Thanks again all.
 

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