Torque sensor on the throttle pin out of an aftermarket controller?

[Wouter KE]

Has anyone ever experimented with a torque sensor connected to the throttle pinout of a cheap aftermarket controller on a hub motor? Or does Anyone know if this could work?
I was thinking about Sempu T2 sensor (https://www.aliexpress.com/item/32967314504.html?gatewayAdapt=glo2nld) or similar.
Throttles produce an analog signal, usually something between 1 and 4 V and this type of torque sensor has an output between 1,5 and 3V. Speed set of aftermarket controllers is usually 1-4.2 V. The problem I see arise here is the desired minimum of 8 Volts input and, once connected, setting the right multiplier.
I don't need a throttle; I live in Belgium, and law forbids the use of a throttle. So I might as well try to connect a torque sensor to the pinout of the throttle.
This is ment to revive a Koga with ION rear hub motor. This motor will only run on its own Ion battery, which is not available anymore (and which was horribly expensive in the days it was still for sale). So I hacked the motor, removed the internal controller and led out the phase wires in order to run the motor on an external controller, this is supposed to work. (

). But I would also like to get the smootness of running on a torque sensor.

 

[ferret]

Hi.
I dont know which controller are you using but generally; for riding at constant speed, the throttle input to the controller needs to be constant (at a voltage proportional to the desired speed).
When pedaling, the torque sensor outputs a rising and falling signal proportional to the force applied to the pedals. Sending this pulsing signal to the throttle input of a simple controller will cause the motor to constantly accelerate and decelerate, not maintain constant speed.
Advanced controllers have dedicated inputs for a cadence sensor and a torque sensor and use software algorithm to drive the motor at the correct speed according to their values.
Mid tier controllers requires just a cadance sensor which can be a good compromise.
Avner

 

[d8veh]

Has anyone ever experimented with a torque sensor connected to the throttle pinout of a cheap aftermarket controller on a hub motor? Or does Anyone know if this could work?
I was thinking about Sempu T2 sensor (https://www.aliexpress.com/item/32967314504.html?gatewayAdapt=glo2nld) or similar.
Throttles produce an analog signal, usually something between 1 and 4 V and this type of torque sensor has an output between 1,5 and 3V. Speed set of aftermarket controllers is usually 1-4.2 V. The problem I see arise here is the desired minimum of 8 Volts input and, once connected, setting the right multiplier.
I don't need a throttle; I live in Belgium, and law forbids the use of a throttle. So I might as well try to connect a torque sensor to the pinout of the throttle.
This is ment to revive a Koga with ION rear hub motor. This motor will only run on its own Ion battery, which is not available anymore (and which was horribly expensive in the days it was still for sale). So I hacked the motor, removed the internal controller and led out the phase wires in order to run the motor on an external controller, this is supposed to work. (

). But I would also like to get the smootness of running on a torque sensor.

If you take the output of the torque sensor direct to the throttle input, it won't be very pleasant. The signal will be up and down while you pedal, but what you need is some sort of smoothing.

You can achieve what you want by using a Cycle Analyst, but that's relatively expensive and complicated compared with other solutions. You can get a really nice ride using a KT controller and KT LCD. The pedal assist function is very good, as it uses current control instead of the normal speed control. You can also set it up to use the throttle up to be dependent on pedalling as an instant full-power over-ride of the pedal assist setting, which is legal and very useful.

 

[Wouter KE]

Thanks for your input Ferret and d8veh, I had no idea of the rising and falling signal state of the torque sensor. Yes, I have been looking at the Grin stuff, really nice, but they are somewhat over my budget. In Europe the cheapest combination of Baserunner and CA would cost me at least 400 €. Ordering directly from Grin would be even more expensive after import taxes and custom clearance. Besides, I only need 7-17 Amps and I'd also like some fancier display. I'll stick to the KT or Lishui controllers from Aliexpress or Amazon, and try to make them work as smooth as possible.

 

[stancecoke]

You can achieve what you want by using a Cycle Analyst

you don't need additional hardware. There are open source firmware projects for the popular Kunteng (outdated) and Lishui (up to date) controllers. The firmware reads in the torque and the cadence signal of the torquesensor and calculates the motor power from the riders effort, like any Bosch, Yamaha, Panasonic drive does also.

Pmotor = Assistfactor * Phuman = Factor * torque on the crank * cadence

There are many satisfied users.

There are controllers, that support the torquesensor with stock firmware also.

Bafang @windmeile:
https://windmeile.com/shop/e-bike-teile/controller/bafang-controller-fuer-nabenmotor-g040-48v-500w

Lishui @Phoebe Liu

https://www.aliexpress.com/item/4000038619326.html

regards
stancecoke.

 

[Wouter KE]

you don't need additional hardware. There are open source firmware projects for the popular Kunteng (outdated) and Lishui (up to date) controllers. The firmware reads in the torque and the cadence signal of the torquesensor and calculates the motor power from the riders effort, like any Bosch, Yamaha, Panasonic drive does also.

Pmotor = Assistfactor * Phuman = Factor * torque on the crank * cadence

There are many satisfied users.

There are controllers, that support the torquesensor with stock firmware also.

Bafang @windmeile:
https://windmeile.com/shop/e-bike-teile/controller/bafang-controller-fuer-nabenmotor-g040-48v-500w

Lishui @Phoebe Liu

https://www.aliexpress.com/item/4000038619326.html

regards
stancecoke.

Thanks !!!

 

[Wouter KE]

you don't need additional hardware. There are open source firmware projects for the popular Kunteng (outdated) and Lishui (up to date) controllers. The firmware reads in the torque and the cadence signal of the torquesensor and calculates the motor power from the riders effort, like any Bosch, Yamaha, Panasonic drive does also.

Pmotor = Assistfactor * Phuman = Factor * torque on the crank * cadence

There are many satisfied users.

There are controllers, that support the torquesensor with stock firmware also.

Bafang @windmeile:
https://windmeile.com/shop/e-bike-teile/controller/bafang-controller-fuer-nabenmotor-g040-48v-500w

Lishui @Phoebe Liu

https://www.aliexpress.com/item/4000038619326.html

regards
stancecoke.

Euh, excuse me my ignorance - I'm new to this E-bike thing, but could you point out a webpage where I can find some decent documentation on the open source firmware projects you mentionned?

 

[stancecoke]

could you point out a webpage

For both projects there are Wiki pages at GitHub and discussion threads here at ES and in the German Pedelecforum. The Lishiu discussion is mainly on the German forum.

Home

OSEC Open Source E-Bike Controller in a Windows toolchain for a STM8 - stancecoke/BMSBattery_S_controllers_firmware

github.com

Home

Free FOC firmware for Lishui E-Bike-Controllers. Contribute to EBiCS/EBiCS_Firmware development by creating an account on GitHub.

github.com

The Kunteng project is not maintained any more, but it still works.

The Lishiu project is alive and maintained. You can build your individual firmware file at GitHub without any local installation. There is a detailed tutorial in the Wiki of the Pedelecforum:
https://www.pedelecforum.de/wiki/do...uer_lishui_-controller:compilieren_bei_github

The discussion thread is here:
https://www.pedelecforum.de/forum/i...source-firmware-fuer-lishui-controller.61113/

regards
stancecoke

 

[d8veh]

Just a final comment. Some people like torque sensors. I have one on my crank-drive, and I have a cadence sensor on my hub-motor bike with a standard KT controller. Both run at about the same power. I've ridden many hundreds of ebikes of every type looking for one that gives me what I want. For me, the hub-motor bike with KT controller is ebiking nirvana. It gives me much better choice of power and pedal effort. I've been using it for 10 years and done about 10,000 miles on it, and it's been faultless.

My advice would be to try a standard KT controller first, and if you're not happy, you can always try the open source firmware and add a torque sensor later if you think you need it. There's a lot of hype about torque sensors. I try to be objective. They just don't do it for me. Finally, standard Lishui controllers with speed control are pretty well useless, except for very low powered bikes (24v 12 amps), where you don't notice, so keep away from them. I can see that a torque sensor would be a massive improvement for one of those and other speed control controllers.

 

[Zambam]

you don't need additional hardware. There are open source firmware projects for the popular Kunteng (outdated) and Lishui (up to date) controllers. The firmware reads in the torque and the cadence signal of the torquesensor and calculates the motor power from the riders effort, like any Bosch, Yamaha, Panasonic drive does also.

Pmotor = Assistfactor * Phuman = Factor * torque on the crank * cadence

There are many satisfied users.

There are controllers, that support the torquesensor with stock firmware also.

Bafang @windmeile:
https://windmeile.com/shop/e-bike-teile/controller/bafang-controller-fuer-nabenmotor-g040-48v-500w

Lishui @Phoebe Liu

https://www.aliexpress.com/item/4000038619326.html

regards
stancecoke.

Very interesting! Which Torque sensors (link please) works with the Lishui controller?

 

[stancecoke]

I try to be objective

Sorry, but your post is completely subjective.
The vast majority of commercial EBikes is using torquesensors, even in the discounter class, they are getting normal.
You can get Lishui controllers up to 1.8 kW.

E-Bikecontroller - Lishui Controller

Nanjing Lishui Electronics Research Institute Co., Ltd

www.lsdzs.com

Lishui has 30% market share on european OEM EBikes. The Kunteng hardware is completly outdated.

Which Torque sensors (link please) works with the Lishui controller?

They are available at Phoebe Liu also:

PHOEBELIU EV PARTS&tools Store - Amazing products with exclusive discounts on AliExpress

Discover the wide range of from AliExpress Top Seller PHOEBELIU EV PARTS&tools Store.Enjoy ✓Free Shipping Worldwide! ✓Limited Time Sale ✓Easy Return.

phoebeevparts.de.aliexpress.com

But there are many other sources also. Just search for "ERider bottom bracket torque sensor"

regards
stancecoke

 

[d8veh]

I don't care what anybody else does, neither do I care how old anything is nor what anybody else thinks. I've been involved in electric bikes for 14 years and ridden just about every type of bike that's available in Europe. I simply judge what's in front of me. That's what I mean by being objective.

 

[stancecoke]

what I mean by being objective

But that's subjective. I built my first EBike in 2008 with a simple PAS system. From the first mile it was clear for me, that this is not the way of bicycle riding that I like. There is no wrong or right, it's just a matter of personal preferences...

regards
stancecoke