[JRP3]

So you guys are telling me the Curtis uses a REVERSE taper pot? That's insane It makes no sense for an EV, being the opposite of what you'd want, and it's a less common part than a linear or audio taper pot.

[Tesseract]

Originally Posted by JRP3

So you guys are telling me the Curtis uses a REVERSE taper pot? That's insane It makes no sense for an EV, being the opposite of what you'd want, and it's a less common part than a linear or audio taper pot.

Perhaps... I only got a brief look at a PB-6 about 6 months or so ago, but you can't really argue with results... Audio taper pots are usually made by fusing two different resistance films at the midpoint of rotation, split 20% to the CCW side and 80% CW. If Dimitri sees an 80% change in voltage over the first half of the pedal's travel then it is wired/mounted backwards or else it's an anti-log pot (rare though they are).

[dimitri]

Guys, thanks for all suggestions. I can't tell if this is a bad pot or if its by design, but this is approximately how my throttle input voltage is mapped across the entire operating angle of the PB6 arm.

Curtis.jpg

So, while I am waiting for EVNetics throttle assembly, I followed Qer's suggestion and reduced motor current limit to 700 amps. I also fooled calibration routine to set max value at 85%, rather than 67% which it was detecting before ( I jumped 5V to throttle terminal and ran calibration ). Also, I set slew rate back to 600 A/s to reduce hysteresis.

All these changes combined made significant improvement in pedal range. Its now behaving similar to what I am used to in the past, wider movement range and better response. I am able to maintain any desired running current again.

I still want to replace PB6 with better solution though...

[kek_63]

Maybe I'm misunderstanding things here, but I thought that the PB-6 was only good for 0-5k throttle input signal

Keith

[Tesseract]

Originally Posted by kek_63

Maybe I'm misunderstanding things here, but I thought that the PB-6 was only good for 0-5k throttle input signal

It is - only two wires are brought out from the pot. If you connect a resistor between the reference power supply (+5V) and the throttle input, and the PB-6 to the throttle input and ground, you have turned the PB-6 back into a pot.

This is NOT recommended though, because pots tend to fail open and that would mean full throttle. Of course, if you have the BRAKE input connected to the brake light circuit then if this happened and you stomped on the brakes as instinct would have you do, the Soliton1 will shut down the motor output regardless of what the throttle is saying, interpreting it (correctly) that something has gone wrong.

[Qer]

Originally Posted by dimitri

So, while I am waiting for EVNetics throttle assembly, I followed Qer's suggestion and reduced motor current limit to 700 amps.

Which will decrease the top current at max throttle.

Originally Posted by dimitri

I also fooled calibration routine to set max value at 85%, rather than 67% which it was detecting before ( I jumped 5V to throttle terminal and ran calibration ).

Which also will decrease the top current at max throttle.

I bet that if you run a graph now you'll find that top current will be limited to around 500 Amps, with other words it will behave roughly as your previous beta controller.

Ye canna' change the laws of physics, capt'n.

[Tesseract]

Originally Posted by dimitri

Guys, thanks for all suggestions. I can't tell if this is a bad pot or if its by design, but this is approximately how my throttle input voltage is mapped across the entire operating angle of the PB6 arm. ....

Ummm... so, over the first half of the accelerator pedal's travel the signal goes from 0 to 3V while over the second half in only increase to 3.9V...

If max motor current is 1000A then over the first half of the travel motor amps will range from 0 to 760A, which is about the maximum you seem to get anyway. In essence, then, the second half of your throttle pedal's range is tossed out by the combination of limited battery current/voltage and anti-log throttle behavior.

Setting max motor current to 750A and calibrating properly (rather than trying to fool the controller) is your best solution as of now. *

* - my opinion, of course - YMMV... literally.

[JRP3]

Originally Posted by dimitri

I still want to replace PB6 with better solution though...

I don't think you need to dump the entire setup, just replace the potentiometer with a better one. Talk to Brian, (rctous), as I think he has a supply of quality pots.

[Lordwacky]

Originally Posted by dimitri

This is a commuter vehicle with automatic transmission, so it will behave as such.

....

So I chickened out and reduced my max battery current to 450 amps, better safe than sorry...

So I've been following this thread for a couple of days now. I'm super excited about this new controller it looks freakin awesome. You guys really did a nice job putting it together, a lot of thought went into the feature set. everyone involved should be proud.

My only question for Dimitri is, why did you end up going for such a high powered, high performance controller when clearly all you wanted was a commuter vehicle? Seems like a Curtis or Synkromotive would fit the bill nicely while saving ~$1k.

Not trying to crap on the thread, or your build by any means. I'm just courious, does the Soliton1 offer anything other then high power that would make it worth the expense to the lower power side of the spectrum? A lot of the throttle calibration/ interface features seem really nice, but I think the sykro offers similar options.

[Tesseract]

Originally Posted by Lordwacky

...
My only question for Dimitri is, why did you end up going for such a high powered, high performance controller when clearly all you wanted was a commuter vehicle? Seems like a Curtis or Synkromotive would fit the bill nicely while saving ~$1k.

I believe Dimitri had a Curtis on his first conversion, so he could probably give reasons for not choosing a Curtis the second go around. I could give reasons, too, but I'm hardly unbiased...

Anyway he didn't pay a premium for the Soliton1 because he was a beta tester (the first, actually).

Originally Posted by Lordwacky

...does the Soliton1 offer anything other then high power that would make it worth the expense to the lower power side of the spectrum? ...

I think this is a very legitimate and eminently reasonable question, and my answer might surprise you - if you are not interested in spirited performance from your EV then the Soliton1 is probably not worth the price.

I mean, lots of people - especially lots of people here - are more interested in how cheaply they can convert their vehicles than anything else. They don't seem to mind the crappy performance that comes from saddling a modern vehicle conversion with a "shoebox" controller that reaches current limiting from overtemp within a minute of driving. If any of those style controllers could deliver even 500A continuously they would be fine for most daily drivers... the problem is, they can't. Not a single one of them has the heat removal capability to meet their claimed current rating for more than a few seconds every couple of minutes (and some don't even come close to their claimed current rating, ever... Kel...cough...cough...ly...)

From my perspective - never having seen or tried one personally, that is - the Synkromotive controller appears to be the best choice for smaller and/or lighter vehicles like Dimitri's. There are lots of "features" built-in to the Soliton1 that make it compelling for people with LFP battery packs, and it is certainly easy to install, setup and use, but we are under no illusions here that such is enough to get people to pay $1000 more for it than a Synkro... no, the only reason you will pay that much more money is to get more than twice the power handling capacity...