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Magic Pie 4 (Vector Control)

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Barbados:
is the controller in the Magic Pie 4 the same as in the Smart Pie 4?
how many and what FET's?

Bikemad:
There is no capacitor precharge function in the vector controller so you will still get a nice big fat spark if you are using a battery without BMS and a much reduced spark if you connect to a BMS equipped battery that is already turned on before you connect. ;)

The controllers appear to be physically identical but they are factory loaded with different firmware to suit the particular motor.

The FETs are sealed underneath the circuit board inside the aluminium casing and I am not about to ruin a perfectly good controller just to find out what's inside it.
As these controllers are so compact, I would assume they only have 6 FETs to do the switching just like all the previous GM internal controllers.

Alan
 

Barbados:
hello Alan, thanks for your answers!
6 fet isn't that much :-(  the fan really must help something. 6 fet is the minimum used in any
bike controller I know about.

and the missing spark protection doesn't sound good either

Bikemad:

--- Quote from: rkts on August 14, 2014, 04:29:53 PM ---Well I've just did a test ride on proof of concept front MP III fitted with Vector with some mods on winding  (I was not told what exactly was done - phase shuffle?)
All is working fine. I do not see any ON/OFF behavior however torque is low, especially from full stop. It feels more like 2-3A on MP III however CA readings shows around 20-25A on full throttle. 
Actually I've tried to hold bike with rear brake and do WOT from full stop so it even does not spin front wheel while CA shows around 10-15A draw. Wheel just stays on the ground and after few seconds controller shuts the power to the motor due protection.
I'm not saying it has difficulties to start spinning but it's slow to reach it's RPM even when wheel is lifted. I can ride it from full stop but nothing to compare with original mp3...

Any ideas on why torque is so low? Could it be HAL sensors connected in wrong order or motor would not work in that case at all?

--- End quote ---

Who modified the windings and how did they know what was required?

The low speed torque from my MP4 appears to be a lot more than my MPIII so I would guess that your low torque is because the coil windings are still not optimised correctly to suit to the controller, perhaps your stator was simply rewired from Star to Delta configuration? ???

Is it any faster than it was with the MPIII controller?

I have had a good look at the hall sensor positions on both my original MPIII and the new MP4 and they appear to be in exactly the same position on the stator, so I know that my "all or nothing" throttle problem must be due to the windings.

I don't know exactly what the difference in the windings of the stator is, but it definitely makes a big difference to how the motor performs. ;)

Alan
 

rkts:
Hi Alan,

Guys who modified it are working with GM products for a long time however it's  their initial experience with Vector controller.
This is rather experiment that I've volunteered as my original MP3 controller needed some fixing anyway.

Delta wiring might be exactly what they did. They were having issues to make it work correctly for few days and were unwilling to tell me what they did to make it work :) I will try to ask again.

While speaking about HAL sensors I was guessing not about position but rather incorrect sequence of hall sensors connected. I'm not sure what would be behavior if you change sequence of HAL sensors with this controller? Motor will go in reverse or will loose it's power?

It is not faster, speed is pretty much same but it's harder to reach max speed (due lower torque?) But I'm able to reach around 45kph (5x something while pedaling)
But for delta wiring I could explain it with 2 factors:
1. Speed It is SW that controls it and it's set to default 380RPM. I might hit that limit. I don't have Vector cable to test it.
2. In theory delta wiring is considered to be low torque at low RPMs but can reach higher speeds on BLDC motors. Are that 380RPM considered to be high enough RPM? For some reason I would say that 10KRPM is high and not ~400.

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