How to change my throttle output signal

[Hugues]

interesting, thanks.

are you sure about the orientaton of the field of the low end magnet ?
On mine, as far as i can remember, it looks like it's pointing opposite to the high end one,
i will check again tonight. How do you determine north on a magnet ?

If it is like in your diagram, then maybe truning the low end magnet (if possible) by 90 degrees counterclockwize cound increase its "pulling down" effect longer ?

[MadRhino]

How do you determine north on a magnet ?

Use a compass, or another magnet with known field direction. The north of your magnet will attract the south of the compass. don't do this too long or close, for it would damage the compass.

I like the external metal ring idea, if it works this could make for an easy tunable throttle.

[Tench]

Fetcher Good call!! This is a problem i am experiencing, my thottle output is 0.86v when closed, the controller doesnt start to power the motor untill 1.5v so i have a lot of the very short rotation lost (30% ish) resulting in a very fast action and abrupt take off which needs to be tamed, i will have a play with mine and see what i can achieve.

Hugues, mine is also the full grip twist throttle from ebikes.ca so if you have any success with that one show us how you did it, if i manage to make any improvements i will post it here.

Thanks guys,

Cheers Simon.

[Hugues]

Hi Tench,

The one I modified is not from ebikes.ca, it's from hi-power cycles.
And the problem was different, I had a burst of power at the end and travel was too long, now fixed. The start-up has always been very smooth on this throttle, not sure what makes it different actually, maybe the orientation of the low end magnet ?

I have 2 throttles from ebikes.ca and they both behave like you describe, start is delayed and too strong. I will post here if I manage to improve on them,

[fechter]

Placing a variable resistor in series with the ground wire on the throttle will allow you to adjust the zero point. I've found this helps a lot to smooth out the low end throttle response.

[Tench]

Placing a variable resistor in series with the ground wire on the throttle will allow you to adjust the zero point. I've found this helps a lot to smooth out the low end throttle response.

I reside under the heading off dummy when it comes to electronics, can you show exactly how to connect that so i can give it a go,

Thanks Simon.

[fechter]

I know it's posted somewhere but I can't find it

I used a 10 turn 1k trimmer pot in series with the ground wire going to the throttle. I cut the black wire and connected the ends to the resistor. Be sure to put the wheel off the ground when you first turn on the controller as the motor might start running.

With the controller on, you adjust the trimmer pot until the motor starts to move, then back off until it just stops. It's a good idea to back it off a tiny bit more just so variations in temperature don't cause the motor to start creeping at stop.

Throttle smoother.jpg (58.28 KiB) Viewed 1167 times

Tape it up or use heat shrink after connecting. The trimmer can be anywhere between the throttle and controller. On mine, the final setting was around 200 ohms.

[Tench]

Fetcher your a Star!! i did this today, i can now pull the signal up to just before the controller activates the motor which gives me much better throttle action and control finesse.

Thanks for your imput, it has helped me to make an huge improvement and taught me some more about simple electronics and ebike systems.

Cheers Simon.

[fechter]

Good work.

I found the throttle response is fairly progressive near the low end and gets steeper toward the middle of the range. If your controller doesn't start activating until the throttle is in this steep section, you get a very twitchy low end. By shifting the zero point downward, you regain the progressive part of the curve and the low end is much less sensitive.

[Skippic]

Is there a way of changing the throttle to work like it does on a car. Regulate thrust (Amps) instead of speed?

[fechter]

Is there a way of changing the throttle to work like it does on a car. Regulate thrust (Amps) instead of speed?

Yes, but that is a controller function, not the throttle itself. I designed a circuit that does this, but it's better if the controller has that function.

[teklektik]

A Cycle Analyst can do this - see section 9.3 of the v2.23 CA User Manual. Your throttle signal drives the CA to determine the percentage of configured Max Amps, then the CA generates an appropriate throttle signal that drives your controller. The CA jiggles its throttle signal according to on-the-fly Amp measurements.

[spuzzete]

I know it's posted somewhere but I can't find it

I used a 10 turn 1k trimmer pot in series with the ground wire going to the throttle. I cut the black wire and connected the ends to the resistor. Be sure to put the wheel off the ground when you first turn on the controller as the motor might start running.

With the controller on, you adjust the trimmer pot until the motor starts to move, then back off until it just stops. It's a good idea to back it off a tiny bit more just so variations in temperature don't cause the motor to start creeping at stop.

Throttle smoother.jpg

Tape it up or use heat shrink after connecting. The trimmer can be anywhere between the throttle and controller. On mine, the final setting was around 200 ohms.

Thanks Fechter!

I had the same problem on my bmsbattery kit (36v 500w rear hub and ku123 controller) and your solution seems to work great! I just installed and adjusted the 1k trimmer, the throttle seems to be "sensing" though all the curve, so if I accelerate only for 1/10 of the throttle the motor responds linearly, before it was going 100% from still no matter how gentle I was on the throttle.

Thanks for sharing this!