# Brushless motors two questions



## Stype (Aug 28, 2009)

Hi, maybe you can help me with some design,

Please try to answer those two questions:
1. Does the motor with 7 pole pair offers approximately 7 times slower minimum (stable) speed then the motor with 1 pole pair ?

2. Let's say I'm using vector control for achieving the minimum stable speed and I get 10rpm. Could you take an educated guess and say what would probably be the min stable speed using scalar control, or even more simple, using Trapezoidal control with hall sensors?

If yo don't know the answers to both questions please answer the one you know. 

Tnx


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## 69mkitmine (May 31, 2007)

Yes. twice in one night.


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## hatcher#56 (Oct 28, 2007)

69mkitmine said:


> Yes. twice in one night.


lol:tongue:


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## bnc_customs (Dec 2, 2007)

ive seen it all now lol


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## Tehachapi Flash (Mar 30, 2006)

#1. Simple yes.

#2. Depending on the parasitic whirling ocillation of the parsipial mode, you would experience an anular quasi inepular of around 32 degrees kelvin. In other words, the hall sensors would be useless once power is applied. Good luck, Ron


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## 69mkitmine (May 31, 2007)

I concur.


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## rocketron (Dec 2, 2003)

you maybe ONto something


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## RPM (Dec 20, 2004)

Tehachapi Flash said:


> #1. Simple yes.
> 
> #2. Depending on the parasitic whirling ocillation of the parsipial mode, you would experience an anular quasi inepular of around 32 degrees kelvin. In other words, the hall sensors would be useless once power is applied. Good luck, Ron


And I thought I had these brushless motors all figured out! LOL!


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## tats31 (Jun 11, 2006)

I just need a flux capacitor


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## 69mkitmine (May 31, 2007)

tats31 said:


> I just need a flux capacitor


and 1.21 jiggawatts!!!:thumbsup:


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## JDW (Oct 29, 2006)

69mkitmine said:


> and 1.21 jiggawatts!!!:thumbsup:


What the hell is a Jiggawat

Jake


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## 69mkitmine (May 31, 2007)

JDW said:


> What the hell is a Jiggawat
> 
> Jake


It's like a Gigawatt....only more "rural"


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## hatcher#56 (Oct 28, 2007)

69mkitmine said:


> It's like a Gigawatt....only more "rural"


now thats funny right there ,i dont care who u are:thumbsup:


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