Making a torque throttle instead of a speed throttle for a cheap controller

[Bobbo1260]

Thanks for feedback.
So from what I understand I would need to replace the existing battery mount that has the integrated lishui controller and source a plain battery mount with a pos and neg wire to supply a replacement controller and source a display suited the replacement controller.
The existing motor, brake levers, PAS sensor, light, display and throttle all have Juliet connectors.
Would you know of a particular matched controller and display that I could£ plug the existing components into.
My current KD21C display allows programming of the number of pedal assist modes and percentage of power in each of the levels of pedal assist which I would like to still have along with a throttle that can be programmed to say 6mph.
Any advice gratefully received.

 

[saneagle]

Thanks for feedback.
So from what I understand I would need to replace the existing battery mount that has the integrated lishui controller and source a plain battery mount with a pos and neg wire to supply a replacement controller and source a display suited the replacement controller.
The existing motor, brake levers, PAS sensor, light, display and throttle all have Juliet connectors.
Would you know of a particular matched controller and display that I could£ plug the existing components into.
My current KD21C display allows programming of the number of pedal assist modes and percentage of power in each of the levels of pedal assist which I would like to still have along with a throttle that can be programmed to say 6mph.
Any advice gratefully received.

You have a choice. You can either use an external controller in a bag or box, or you can get the correct fitting Hailong type controller from Topbikekit that slots straight in to your mount. You just need to unsolder your battery connector and solder the wires to the new one.

 

[Bobbo1260]

Thanks for that.
Forgive my ignorance, but to make sure I’m understanding this right, I take the existing luishi controller out of the existing battery holder and solder in a replacement KT controller?
Would the existing KD12C display work with the Kt controller or would I need to change the display to suit the KT controller.

 

[Nealh]

Thanks for that.
Forgive my ignorance, but to make sure I’m understanding this right, I take the existing luishi controller out of the existing battery holder and solder in a replacement KT controller?
Would the existing KD12C display work with the Kt controller or would I need to change the display to suit the KT controller.

One replaces the Lishui controller unit like for like with a KT controller unit, simply unbolt/unscrew the controller unit from the battery mount rail. (One of course has to buy the correct controller unit for the battery).
One will need to buy a KT LCD for compatibility.

 

[saneagle]

Thanks for that.
Forgive my ignorance, but to make sure I’m understanding this right, I take the existing luishi controller out of the existing battery holder and solder in a replacement KT controller?
Would the existing KD12C display work with the Kt controller or would I need to change the display to suit the KT controller.

You definitely need to replace the LCD. Your brakes and pedal sensor have a chance of working with it, but quite often the connectors are wired differently even though they look like they match.

The controller clips into the battery holder. With the battery removed, there are two small screws in the plastic cover. Take them off and lift up the back a bit to peek inside, then you can see exactly which controller you have to check that the size and shape matches the TBK one. You have to remove the holder from your downtube completely to remove the controller or to get a better look at it, which is still only two or three screws more.

 

[Bobbo1260]

I had a look at KT controllers and displays but they don’t seem to allow much adjustment of the levels of pedal assist as my current set up does.
Seeing as the main issue with my current set up is that the throttle goes from 0 to 15mph which is illegal in the uk i’m wondering if some resistors could be added between the throttle and controller to reduce the maximum throttle speed to say 6mph which would be fast enough to allow the pedal assist to kick in and me to get my balance.

 

[saneagle]

I had a look at KT controllers and displays but they don’t seem to allow much adjustment of the levels of pedal assist as my current set up does.
Seeing as the main issue with my current set up is that the throttle goes from 0 to 15mph which is illegal in the uk i’m wondering if some resistors could be added between the throttle and controller to reduce the maximum throttle speed to say 6mph which would be fast enough to allow the pedal assist to kick in and me to get my balance.

All you need is a small potentiometer on the throttle signal wire. Connect one side to the signal wire coming from the throttle, the other side to ground and the wiper to the controller. A 10k one should work. If you install it at the controller end, nobody will know it's there. You will able to set the maximum speed at whatever you want less than what you already have, as it will only adjust downwards.

10Pcs Potentiometer Trimpot Variable Resistor Adjustable Resistance RP 13 Values | eBay

Good Good quality.

www.ebay.co.uk

You can also make a 6km/hr start up button with one. One side goes to ground, the other side to the red 5v wire via a push button switch, and the wiper goes to the controller as the throttle signal. You can then adjust the potentiometer to set the speed the bike goes when you push the button. I made a cruise control like that before we had decent controllers. I had the potentiometer on my handlebars. I used a three-pole switch to switch from normal throttle to the potentiometer one for cruise. Post #2 here 13 years ago!

Looking for Daahub style micro throttle/cruise control for Cyclezee mk1 kit

I am looking for a Daahub style micro throttle switch to supplement the twist grip throttle on my Cyclezee kit. In an ideal world it would be like cruise control. I am happy with what I guess to be about 70% for cruising into wind or slightly up hill. On the flat or better I am happy providing...

www.pedelecs.co.uk

 

[Bobbo1260]

Thanks very much for this, as this seems an ideal solution. The illustration in your older post is good, as even with my limited electrical knowledge I can understand and replicate it.
Sadly, walk in shops such as Maplins and Tandy’s disappeared off the high street some years ago, as they were always good for purchasing electrical components.

 

[Nealh]

The five current levels though not adjustable one can can theorectically lessened any power by using C5.
The set current levels give approx. 13%, 20%, 33%, 50% & 100% power in each of the PAS levels.

 

[Bobbo1260]

One advantage about the KD21C that came with my Yosepower kit is that you have the option of PAS settings 0-5, 0-7 and 0-9 and the power percentage within each level can be customised. The thumb throttle irrespective of these setting remains unchanged ranging from 0-15 mph. Using the the suggested potentiometer method reducing my throttle to 4mph will make it road legal. I will in fact be limiting the throttle to 6mph but I can’t see police being to concerned about an additional 2mph.