KT-LCD3 versions? Max speed and PAS settings

E-HP

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I have a KT-LCD3 that came bundled with a Risun 18 FET sine wave controller. I have both working great now, but I'm trying to fine tune the cadence based PAS system. Here's what I found that is odd:

The instructions that came with the LCD3 are the same as the many manuals that you can find online, and the videos people post on YouTube. But, the available options for at least two of the setting is different on the actual unit. For the maximum speed setting, everything I've seen online shows the max as 72, but on my unit the max is 99.

For the PAS sensor setting, C1, I've found that the only value that detects the PAS sensor is C1=04, which isn't defined in most of the manuals (most define 0-4, based on the magnet configuration). I had forgotten this about C1 when I first set up the controller, and had decided to sort it out later, so when I added more magnets to my disc this weekend, and set C1=02 for a 10 magnet sensor, no PAS.

With C1=4 and 10 magnets, the cadence the controller thinks it sees is too fast, so on level 1, I'm barely providing any pedal effort even in my top gear (which is low, 40:13, since I'm only running one chainring up front). If I can't figure out how to change the setting, I'll likely remove two of the new magnets so that I'm contributing more at the lower settings. My thought is to remove the ones that the sensor would see just before my power stroke on the pedals, since I like how fast PAS comes on from a standing start with the additional magnets. I only have them hot glued in for now so I can fine tune.

Anyone out there own a KT-LCD3 with the same odd settings above? I'm hoping that one of the other settings affects which setting work for C1, but haven't figured that out yet.
 

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Hi there,

I don't know if my posting is of any help but there you go :mrgreen:

To my limited knowledge (owning two LCD3 displays, one LCD6 and one LCD8S) 72 km/h is the max speed configurable for all displays. If yours has a higher maximum speed, then it simply could be a newer software version ?

In regard to the PAS configuration it has always been a hit and miss game for me. Usually those simple PAS sensors with 5-6 magnets in the discs play nicely with C1=0-2 depending on the responsiveness you want. The same sensors together with > 8 magnets in the disc caused unstable recognition of the cadence for me at certain RPMs.

There are different PAS sensors out there though which provide a different signal form with smaller but much quicker signals. Usually they are more responsive. The only advice I truly can give you: If you are serious about fine tuning the responsiveness of your PAS is to get both sensor types (the "faster ones" are usually called V12. The webpages below are in German. Sorry, but I guess you can see the difference in the physical appearance compare to the more simple sensors.
https://www.i-e-e.info/12-er-magnetscheibe-geteilt-typ-v12/
https://www.i-e-e.info/kt-v12l-tretlagersensor-12-magnete-integriert/

By both trying variations of PAS sensor, magnet discs and C1 values one usually finds a good working combination. It can be quite tedious and time consuming though. :mrgreen:

A friend of mine had issues with motor support when pedaling slowly. We first switched from a "forward" PAS with 5 magnets in the disc to a super sensitive V12 PAS with 12 magnets which also cause issues. In the end we sticked to the old forward sensor but using a disc with 8 magnets which work fine up to this day. To my limited understanding there is not THE PAS sensor plus C1 setting which suits any controller, user and use case. As always YMMV
 
Thanks. That's good info on the V12 sensors. I think I'll stick with my current hardware and just tweak the number of magnets then. It's already worked OK with 5 magnets, but I just wanted the motor to provide a little more assistance at the various levels, and for the PAS to start earlier from a standing start (which it's doing now).
 
You're welcome !

It seems that the 12 in the model type indicates the newer version of sensors.
Kuteng labels them also with a 12:
http://www.szktdz.com/en/news.php?type=345

KT-V12:
http://www.szktdz.com/en/news_show.php?article_id=392

KT-D12:
http://www.szktdz.com/en/news_show.php?article_id=487
 
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