Some controllers have wires that you can connect to limit the speed to 15 mph. How does the controller know the speed if diferent motors have different numbers of magnets and poles and there is no external speed sensor, or is just an approximate speed limit , which is different for each motor? Can it even calculate the RPM somehow?
Controller Speed Limit
- Thread starter d8veh
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friendly1uk
1 MW
My 6kmh button is 6mph.
It is possible the controller expects a 201 motor with a minimal 8 pairs and a nice common 26" wheel.
It is possible the controller expects a 201 motor with a minimal 8 pairs and a nice common 26" wheel.
dogman dan
1 PW
I think its more of a watt limiter than a speed limiter. So the limit would vary if the motor is different enough.
In other cases it might be an actual speed limiter. In this case the controller would have to be able to have a speed sensor input from the motor.
In other cases it might be an actual speed limiter. In this case the controller would have to be able to have a speed sensor input from the motor.
Thanks for that.
I've done a bit more research, and found out that the KU63 controller does it by bringing in a 20k resistor in series with the throttles 10k resistor to make a 2/3 divider on the throttle signal. I was hoping for more technical details on how other controllers do it, but I guess nobody knows.
I've done a bit more research, and found out that the KU63 controller does it by bringing in a 20k resistor in series with the throttles 10k resistor to make a 2/3 divider on the throttle signal. I was hoping for more technical details on how other controllers do it, but I guess nobody knows.
Ykick
1 GW
With my Lyen EB312 board controllers it seems to be a mixture of power/speed limiting.
Spinning in free air the controller merely rolls back when the selected % speed is reached. It senses motor speed by way of the Hall sensors and Phase power. Somewhat different than how a CA uses road speed measurement (or single Hall sensor) for speed/throttle control.
However, under load, Lyen controller “speed limit” logic becomes fuzzier. Hard to describe but kinda how “cruise control” rolls off throttle setting when the cruise speed set point is reached but allows for power/throttle to be delivered as the motor speed slows just a bit while under load?
Definitely interesting stuff and something I’ve become much more aware riding smaller geared hub motors. I run high battery pack voltages for geared motors but use controller speed limits so not to overspeed the planetary gear reduction.
Spinning in free air the controller merely rolls back when the selected % speed is reached. It senses motor speed by way of the Hall sensors and Phase power. Somewhat different than how a CA uses road speed measurement (or single Hall sensor) for speed/throttle control.
However, under load, Lyen controller “speed limit” logic becomes fuzzier. Hard to describe but kinda how “cruise control” rolls off throttle setting when the cruise speed set point is reached but allows for power/throttle to be delivered as the motor speed slows just a bit while under load?
Definitely interesting stuff and something I’ve become much more aware riding smaller geared hub motors. I run high battery pack voltages for geared motors but use controller speed limits so not to overspeed the planetary gear reduction.
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