KT-LCD3 speed sensor turns off when motor is not on...

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rmanalan   1 mW

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KT-LCD3 speed sensor turns off when motor is not on...

Post by rmanalan » Jun 27 2016 1:35pm

I just recently installed an EBO Phantom kit from Electric Bike Outfitters http://www.electricbikeoutfitters.com/ebo-phantom.aspx. It's 350w geared hub motor+36v/10ah and comes with a KT-LCD3. One thing that's really annoying is that when in PAS mode and I'm not pedaling, the speed sensor goes back to 0mph. Is that typical of all custom electric bike setups?

Also, once in a while, after a 5-10 mile ride (on a full charge), the system just shuts off. I wondered if it's shutting off due to the minimum voltage setting on the LCD3, so I adjusted it to a lower voltage cut-off, but it still happens. This often happens when I'm at a stop light... hasn't happened while I'm pedaling yet.

Avitt   100 W

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by Avitt » Jun 27 2016 2:08pm

These symptoms indicate that you are either not using a speed sensor, or the sped sensor is not working correctly.

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rmanalan   1 mW

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by rmanalan » Jun 27 2016 5:17pm

Avitt wrote:These symptoms indicate that you are either not using a speed sensor, or the sped sensor is not working correctly.
Not sure that's it. Upon further inspection, my kit uses a custom embedded controller setup from Kunteng http://www.szktdz.com/en/news_show.php?article_id=361. This controller doesn't seem to have a separate speed sensor input.... so it's probably just getting it from the motor.

Anyway, while I like the look of this embedded setup, I'm not fond of this controller.

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by Avitt » Jun 27 2016 7:31pm

If there is no speed sensor, then yes, the speed will be computed from motor speed. (This is why it shows 0 when you are coasting). Also, I believe that most of these KT controllers shut down when they get no speed sensor input for 5 or 10 minutes. If you can't add a speed sensor to your controller, then you may be able to work around by periodically making a manual input on the LCD3 (for example, change the PAS level every 5 minutes or so).

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by d8veh » Jun 28 2016 4:24am

This happens when you use a geared hub-motor without a separate speed sensor. It's easy to fix. All you need is a wheel-speed sensor off an old cycle computer, or you can cut one off the cheapest cycle computers from Ebay that cost about $3.

All you need is the spoke magnet and the sensor. Mount them like in the cycle computer instructions, then join one wire to the white wire in the motor connector and the other to ground. If that doesn't work, connect the second wire to any 5v wire instead of ground.

If you have moulded connectors, open the controller and cut the white wire so that you can make a connection to it. The red wires that go to the throttle and PAS are 5v. If you look at the controller's pcb, all the 5v and all the thin ground wires come from the same place. There's often spare pads to solder wires to.

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rmanalan   1 mW

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by rmanalan » Jun 28 2016 12:05pm

d8veh wrote:This happens when you use a geared hub-motor without a separate speed sensor. It's easy to fix. All you need is a wheel-speed sensor off an old cycle computer, or you can cut one off the cheapest cycle computers from Ebay that cost about $3.

All you need is the spoke magnet and the sensor. Mount them like in the cycle computer instructions, then join one wire to the white wire in the motor connector and the other to ground. If that doesn't work, connect the second wire to any 5v wire instead of ground.

If you have moulded connectors, open the controller and cut the white wire so that you can make a connection to it. The red wires that go to the throttle and PAS are 5v. If you look at the controller's pcb, all the 5v and all the thin ground wires come from the same place. There's often spare pads to solder wires to.
Thanks @d8veh. I tried this out this morning, but it doesn't seem to work. Here's what I did:

Image

Any other ideas?

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by d8veh » Jun 28 2016 5:14pm

Did you try connecting the second wire to ground instead of 5v?

Did you confirm that the speed sensor was switching when the magnet came past?

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rmanalan   1 mW

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by rmanalan » Jun 28 2016 5:41pm

d8veh wrote:Did you try connecting the second wire to ground instead of 5v?

Did you confirm that the speed sensor was switching when the magnet came past?
I didn't try connecting it to ground... I'll do that next. Yes, I did confirm that the speed sensor was switching.

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rmanalan   1 mW

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by rmanalan » Jun 28 2016 6:04pm

Should the white wire from the motor continue to be connected to the controller? Right now I have both the white wire from the motor and the external speed sensor connected to the white wire on the controller.

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by d8veh » Jun 30 2016 4:04am

rmanalan wrote:Should the white wire from the motor continue to be connected to the controller? Right now I have both the white wire from the motor and the external speed sensor connected to the white wire on the controller.
No. Cut the white wire. Join the controller side to either side of the speed sensor and the other to any ground.

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by papicdu1 » Jul 19 2016 3:33pm

Hi, i check Today yours method, but dont work.From magnet sensor go 2 wires, black and red.My controler its KT 48 zwsm-fz02e and hi dont have output for Speed senzor.Motor have 8 wires, no White wire for Speed signal..I connect red and black wire over pas, but pas have 3 wire.Dont work in any combination

kappa7   100 µW

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Re: KT-LCD3 speed sensor turns off when motor is not on...

Post by kappa7 » Nov 23 2016 2:48pm

You have also to tell the controller that you are using a speed sensor:
This is achieved by setting the P2 parameter with how many pulses per revolution give your sensor (0 mean disabled, probably your current setting).
See here to know how to change the parameter.

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