Speed sensor on direct drive and KT controller

[Colone]

Hello everyone,
For a new project I'm working on, I had to buy a new controller. So, I purchased a KT-type controller, with a display and everything. However, I kept my old motor. It's a 500 W direct drive motor that I originally bought as a kit with a generic controller and an SW 900 display. On the new KT controller, the cable connecting the controller to the motor has nine pins, but there are only eight wires coming out of my motor (3 for phases, 1 sensors for each phase, the + and the ground). The missing cable is for the thermistor/speed sensor. So, I connected all the cables except for this one. I turned on the system, and indeed, the motor runs and works correctly. However, on the display, I have no information about the speed.. that was expected. But when I used the system back in the days, I did get speed information on the SW 900 display even though this additional cable was not present. What can I do? I'm currently at the end of my knowledge, and it would bother me to ride with the speed constantly at 0 on the display.
Thank you, any help is welcome.

 

[AGS]

You need to set P1 and P2 correctly on the display for the speed to work. The KT controller doesn’t need the white wire connected because it gets the speed information from the hall sensors. It offers the chance to use the white wire for a temperature sensor instead of a speed sensor.

 

[Colone]

You need to set P1 and P2 correctly on the display for the speed to work. The KT controller doesn’t need the white wire connected because it gets the speed information from the hall sensors. It offers the chance to use the white wire for a temperature sensor instead of a speed sensor.

Alright, that's great news! So, no need to install a speed sensor.. thank you for your response! The bad news now is that I got the LCD 11, which if I understand correctly, only has 3 settings: maximum speed, wheel diameter, and unit of measure.. haha any ideas?

 

[B_c]

I think your LCD has additional settings like other LCDs. Here's a video on YouTube showing how to set parameters such as P1 and P2 and how to access the 'P' or 'C' settings, for example.

Note that P1 is the number of magnets, and P2 is the speed sensor that you don't have, so P2 equals 0.

 

[Colone]

I think your LCD has additional settings like other LCDs. Here's a video on YouTube showing how to set parameters such as P1 and P2 and how to access the 'P' or 'C' settings, for example.

Note that P1 is the number of magnets, and P2 is the speed sensor that you don't have, so P2 equals 0.

Ok thanks a lot ! But according to the user manual my lcd has no other settings here’s a link : http://www.szktdz.com/upload/file/20210427/20210427150702_96544.pdf

 

[B_c]

Perhaps your LCD has outdated firmware or, if I may say, it's locked. I see in this manual that you can access other settings.

Have you tried if you can enter the 'P' settings with your LCD?

 

[AGS]

I’m not sure the LCD 11 has the ability to set up the P and C parameters. It’s too basic. It will have to be connected to a KT display that has all of the correct parameters set up and the data copied across.

 

[B_c]

In the previous comment I wrote, you can see in the link that the KT-LCD11 can do that.

It depends on which firmware is in the LCD.

 

[Colone]

In the previous comment I wrote, you can see in the link that the KT-LCD11 can do that.

It depends on which firmware is in the LCD.

Yes, thank you, I saw your link which goes more in detail than mine. I'll try it as soon as I get home. I really hope it works, and that I can finally have the speed displayed on the screen. If it really doesn't work, I'll return the screen as it's new and order a more advanced one, like the lcd8h, for example ? Thank you for the help.

 

[B_c]

I have an even smaller KT-LCD4, or it's the same size as yours, and I can access all the settings.

We'll see when you get home.

 

[docw009]

The LCD11 seems to have the same P1 and C numbers as the older LCD3. Set P2=0 and you should get speed.

P2 Wheel Speed Pulse Signal Setting - KUNTENG KT-LCD11 User Manual [Page 18]

KUNTENG KT-LCD11 Manual Online: P2 Wheel Speed Pulse Signal Setting. Enter P2 parameter setting interface, then P2 parameter column flashes. P2 is wheel speed pulse signal setting, if wheel generated 1 pulse signal by a revolution, P2 should be set as1. If wheel generated 6 pulse...

www.manualslib.com

By the way, I had anSw900 unit with controller, What a POS. No speed when using a geared hub, Designed only for direct drive,

 

[Colone]

The LCD11 seems to have the same P1 and C numbers as the older LCD3. Set P2=0 and you should get speed.

P2 Wheel Speed Pulse Signal Setting - KUNTENG KT-LCD11 User Manual [Page 18]

KUNTENG KT-LCD11 Manual Online: P2 Wheel Speed Pulse Signal Setting. Enter P2 parameter setting interface, then P2 parameter column flashes. P2 is wheel speed pulse signal setting, if wheel generated 1 pulse signal by a revolution, P2 should be set as1. If wheel generated 6 pulse...

www.manualslib.com

By the way, I had anSw900 unit with controller, What a POS. No speed when using a geared hub, Designed only for direct drive,

Yes thanks ! I should be good, gonna try that when I come back home !
Actually, I really liked the SW900, but it's true that without a speed sensor, the controller relies only on the Hall sensors. However, with a non-direct drive motor, one rotation of the wheel is not necessarily equal to one rotation of the motor, so the speed can be inaccurate or even non-existent (for example, if you pedal faster than the assist itself).

 

[B_c]

Yes thanks ! I should be good, gonna try that when I come back home !
Actually, I really liked the SW900, but it's true that without a speed sensor, the controller relies only on the Hall sensors. However, with a non-direct drive motor, one rotation of the wheel is not necessarily equal to one rotation of the motor, so the speed can be inaccurate or even non-existent (for example, if you pedal faster than the assist itself).

To facilitate understanding, the speed sensor in geared motors is mounted at a location where it senses the rotation of the wheel, and it does so consistently even when the assist level is set to 0.

After a certain period, during one rotation, the controller observes and sends the information to the LCD as the ”time” . And this "time" is taken by the LCD from the controller, which then calculates the speed using the information you have already input into the LCD as the wheel size.

In the case of geared motors, the Hall sensor is placed on the motor, and if the motor is not turning, you cannot obtain the speed.

Similarly, it can be imagined that in a direct-drive motor, the Hall sensor is placed where it senses the rotation of the wheel, and it does so consistently.

And that's why a direct-drive motor doesn't require a speed sensor because the Hall sensor can perform the same function as speed sensor.

I understand it this way, but there might be someone who can explain it better.

 

[Colone]

Perhaps your LCD has outdated firmware or, if I may say, it's locked. I see in this manual that you can access other settings.

Have you tried if you can enter the 'P' settings with your LCD?

Well.. I just checked : there's no way to access the P settings on the screen... maybe my screen is an older version? I'm thinking of returning it.

 

[B_c]

If you've tried entering the P settings correctly and it's not working, it would be best to get another display with all the settings.

 

[Colone]

If you've tried entering the P settings correctly and it's not working, it would be best to get another display with all the settings.

Yeah I tried correctly but impossible..and just to be sure : are these settings dependent on the screen and not the controller?

 

[Chalo]

I have only worked with a few dozen KT controllers, and only four or five different versions, but all of them and their display units allowed access to P and C settings. Are you sure you're using the right series of secret handshakes? It's easy, but not self-evident how to get in there.

 

[Colone]

I have only worked with a few dozen KT controllers, and only four or five different versions, but all of them and their display units allowed access to P and C settings. Are you sure you're using the right series of secret handshakes? It's easy, but not self-evident how to get in there.

http://www.szktdz.com/upload/file/20230921/20230921121712_50166.pdf

I read this manual carefully, tried several times but nothing happened. Strange thing is that the paper manual I received with the display only mention 3 setting : max speed, wheel diameter and unit. But both (the pdf manual and mine) are KT-LCD11.

 

[Chalo]

http://www.szktdz.com/upload/file/20230921/20230921121712_50166.pdf

I read this manual carefully, tried several times but nothing happened. Strange thing is that the paper manual I received with the display only mention 3 setting : max speed, wheel diameter and unit. But both (the pdf manual and mine) are KT-LCD11.

I've used the LCD11 on my darlin's bike. Like LCD3 and LCD4, after you set units and poke the on button one more time (so the setting stops blinking), then you push and hold up and down buttons at the same time until it displays a blinking P1. Then you set P1 through P5 and give it another poke to stop it blinking, and then you can push and hold up and down buttons to get C1.

 

[slaphappygamer]

I have a KT controller too. The part, in the manual, that I missed was the bit that states "Within 5 seconds after boot-up". Only THEN will the settings be accessed. It threw me off because I was trying to get into the settings during test rides. I could never do it because, "Within 5 seconds after boot-up" wasn't achieved.