Adding Pedal Assist option to motor controller...

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Jyee81   1 mW

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Adding Pedal Assist option to motor controller...

Post by Jyee81 » Mar 24 2019 6:25pm

So I'm trying to convert this pedicab into a m mobile food cart now overtime the parts of the Speedy cab ie motor control motor batteries have just given out...they don't make the actual unit with pedal assist anymore and I've ordered 3 separate packages (throttle, controller, and brushless motor) yet either it didn't come with PAS, or the sprocket on the motor was smaller than expected...
Is there ANY way i can add the PEDAL ASSIST OPTION to a controller (i thought maybe utilizing 2 controllers but one will operate throttle and the other controller's throttle wires will be connected to PAS wires...is that possible? Please help...i have been stuck with this dilemma for several weeks....😭

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amberwolf   100 GW

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Re: Adding Pedal Assist option to motor controller...

Post by amberwolf » Mar 24 2019 11:07pm

One easy way to do it is to use the Cycle Analyst v3 from http://ebikes.ca .

It takes your throttle and your PAS and uses them to create a throttle signal to send to the controller to make it do what you want.

You can use a simple cadence PAS (like you probably have now) or a torque sensor.

I would recommend contacting ebikes.ca and letting them know what you have, what you want to do, and they can recommend settings and equipment to work with what you have to do what you want.

Jyee81   1 mW

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Re: Adding Pedal Assist option to motor controller...

Post by Jyee81 » Mar 25 2019 12:55am

Thank you for the advice...I'll definitely give that a try.

Jyee81   1 mW

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Re: Adding Pedal Assist option to motor controller...

Post by Jyee81 » Mar 28 2019 4:50pm

On the actual circuit board of a motor controller what and where is that pedal assist system soldered and what is the label on the circuit board itself for the three wired pedal assist system wires? Also can you solder and add a PAS to the circuit board that doesn't have Pas wires but a throttle? I've been searching high and low for adding a PAs to a controller and found nothing on the contrary I've seen how you can remove the pas but not add by soldering the PAS wires to the circuit board itself...and finally does anyone know what the specifications are for Pas wires I E voltage resistance etc.? Thank you and God bless

Jyee81   1 mW

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Re: Adding Pedal Assist option to motor controller...

Post by Jyee81 » Mar 28 2019 4:50pm

On the actual circuit board of a motor controller what and where is that pedal assist system soldered and what is the label on the circuit board itself for the three wired pedal assist system wires? Also can you solder and add a PAS to the circuit board that doesn't have Pas wires but a throttle? I've been searching high and low for adding a PAs to a controller and found nothing on the contrary I've seen how you can remove the pas but not add by soldering the PAS wires to the circuit board itself...and finally does anyone know what the specifications are for Pas wires I E voltage resistance etc.? Thank you and God bless

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amberwolf   100 GW

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Re: Adding Pedal Assist option to motor controller...

Post by amberwolf » Mar 28 2019 7:00pm

Jyee81 wrote:
Mar 28 2019 4:50pm
On the actual circuit board of a motor controller what and where is that pedal assist system soldered and what is the label on the circuit board itself for the three wired pedal assist system wires?
Depends on teh controller; if it has a PAS input at all it could be marked as anything, unlikley to be marked as "PAS". You could look for other controller threads (taht do have PAS) where poeple have opened them up and noted down what pads they are on the PCB itself, if there are any. But yours could be a totally different place and labelling. :(

I *think* the old Fusin controller I had wiht PAS used something like "ZF" to mark the PAS pad. But even if you find the same marking on yours, it may not mean the same thing.

Also can you solder and add a PAS to the circuit board that doesn't have Pas wires but a throttle?
Not directly, no. You would have to build a PAS-to-throttle module, of whatever electronics are necessary to convert the type of PAS signal you have to the kind of throttle signal the controller requires (after you determine what those are).

There are some threads where people have looked into this, and I think at least one that actually did make one, but I don't have any links. You could do a search on pairs of words like
PAS throttle
in the titles of threads, and display by topic/thread, and look thru the resulting thread list for titles taht might match, like this:
search.php?keywords=PAS+Throttle&terms= ... mit=Search
does anyone know what the specifications are for Pas wires I E voltage resistance etc.?
Depends on the PAS sensor; you'd have to test yours to find out if you don't already know. There are several different kinds, with different outputs. Most are digital in one way or another; some have two separate output signals (to determine direction) and some only have one. Some are PWM output, some are just pulse rate output. A few are analog output (like a throttle, but not the same voltage range).


The only easy off-the-shelf way, without building anything yourself, to add PAS to a controller with no PAS function built in is to use the Cycle Analyst v3 from http://ebikes.ca . I would recommend contacting them to find out what specific hardware you would need, and what settings you might start off with (which you would then tune to get it exactly the way you want it). Depending on the PAS sensor used, you can have cadence control the power, or current, or speed, etc., whick you won't generally get with the various cheap PAS controllers/kits. You can even use a torque sensor (though this may about double the cost) to control those with the force of pedalling as well as the speed.


If you need something cheaper, I'd recommend just replacing the whole controller with one that does PAS, keeping in mind that:
--you'll have ot figure out all the wiring on the new controller to hook it up to your existing system,
--PAS works differently on different controllers, so the one you get may not work the way you would prefer it.

Some, like the KT (kunteng, kun teng) controller kits, have adjustable PAS power levels. I don't have direct experience on them, so you'd want to look at the threads about them for how exactly they work.

Some basically work like my Fusin kit, so the PAS simply activates the full power of whatever level is chosen via the handlebar buttons. It's just on or off, and pedalling harder or softer, faster or slower, doesnt' affect it.

Jyee81   1 mW

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Re: Adding Pedal Assist option to motor controller...

Post by Jyee81 » Mar 29 2019 4:44pm

Thanx for the helpful info...i greatly appreciate it...

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