New book on brushless motors and controllers

[Miles]

http://books.google.co.uk/books?id=lKs7 ... hi&f=false

Seems to be written for the RC modelling enthusiast.

[markobetti]

i like it . Thanks Miles

[Lock]

That looks excellent Miles, thank you (Looks written in a way that EVen I might understand!)

Seems to be written for the RC modelling enthusiast.

Not necessarily, judging by some of his other musings
http://www.amazon.com/Fascination-Quadrocopter-Roland-B%C3%831-4chi/dp/3842367317#_

Buchi.jpg (48.25 KiB) Viewed 1201 times

10Ck

[Miles]

[grindz145]

Where can you get this? I can't seem to find a supplier?

[Miles]

The English version was only published 2 weeks ago....

http://www.amazon.de/Brushless-Motors-a ... B007GCOES4
http://www.amazon.de/Brushless-Motors-C ... -2-catcorr

[Roli]

Hi all

The book is now available on Amazon.co.uk (United Kingdom) and Amazon.com (USA)

Brushless Motors and Controllers on amazon.co.uk
Brushless Motors and Controllers on amazon.com

It is written for model construction, but a large part (more than 100 pages) contains basics of the brushless technology
Yours Roland (the Author)

[Miles]

Thanks Roland.

Looking forward to reading it.

[Thud]

Hmnn.
That link in the OP brings up the issue of "Skin effect" in motor windings....I have long pondered the true benifits if any from the Angle hair wire my toy motors are wound with.....or if my heavy wire is the real winner.

[amberwolf]

I think the main benefit of the thin wire in small motors is it's way easier to wind it quickly, so it's cheaper.

[Kin]

Skin effect only applies to AC I thought? Or are the BLDC motors also going to have skin effect in the windings because the current isn't really direct continuous but rather DC turned on and off rapidly.

[Miles]

Hmnn.
That link in the OP brings up the issue of "Skin effect" in motor windings....I have long pondered the true benifits if any from the Angle hair wire my toy motors are wound with.....or if my heavy wire is the real winner.

You can check here:
http://circuitcalculator.com/wordpress/ ... alculator/

At 1kHz skin depth in copper is 2.4mm......

[Thud]

I guess that rules out the 6mm wire
thanks for the link!

[Alan B]

Was hoping for a Kindle edition, but not.

If there was, would be reading it now.

[Miles]

Was hoping for a Kindle edition, but not.

Here you go: http://www.amazon.de/Brushless-Motors-a ... B007GCOES4

[Miles]

Kindle edition now available from Amazon UK: http://www.amazon.co.uk/kindle/dp/B007G ... eos_detail

[deVries]

Hi all

The book is now available on Amazon.co.uk (United Kingdom) and Amazon.com (USA)

Brushless Motors and Controllers on amazon.co.uk
Brushless Motors and Controllers on amazon.com

It is written for model construction, but a large part (more than 100 pages) contains basics of the brushless technology
Yours Roland (the Author)

You are most welcome to the ES Forum...

Thank you for providing this book & where to buy it.

Can you add any other supplementary or complimentary books or websites you would recommend to go with your book? Both for a beginner or for more advanced knowledge after your book is understood.

Thank you! Please help our forum by posting more advice & help if you have the time. Many people here will be more than appreciative for your help & advice.

Do you post on another Forum too, or do you have a website for motor related information?

Thank you again!

[Miles]

Can you add any other supplementary or complimentary books or websites you would recommend to go with your book? Both for a beginner or for more advanced knowledge after your book is understood.

http://books.google.co.uk/books?id=gbID ... es&f=false

http://books.google.co.uk/books?id=rilV ... CFcQ6AEwBQ

[The more emoticons you use, the less effective........ beyond a certain point it just becomes annoying .]

[Roli]

Hi all

The book is now available on Amazon.co.uk (United Kingdom) and Amazon.com (USA)

Brushless Motors and Controllers on amazon.co.uk
Brushless Motors and Controllers on amazon.com

It is written for model construction, but a large part (more than 100 pages) contains basics of the brushless technology
Yours Roland (the Author)

You are most welcome to the ES Forum...
Thank you for providing this book & where to buy it.
Can you add any other supplementary or complimentary books or websites you would recommend to go with your book? Both for a beginner or for more advanced knowledge after your book is understood.
Thank you! Please help our forum by posting more advice & help if you have the time. Many people here will be more than appreciative for your help & advice.
Do you post on another Forum too, or do you have a website for motor related information?

Thank you again!

Thanks a lot

The aim was to write something, that almost everybody, who it interested in technics, can read and understand. I didn't want to write anything just for academic reasons. So if there is anybody, who has questions about the brushless technology, feel free to post here, and I will try to answer. My background: I am a Professor for Electrical Engineering at Zurich University of Applied Sciences in Switzerland. So far, I don't have any Homepage and Links to Brushless pages (actually, I have some links, but they are written in German).

Yours
Roland

[deVries]

The aim was to write something, that almost everybody, who it interested in technics, can read and understand. I didn't want to write anything just for academic reasons. So if there is anybody, who has questions about the brushless technology, feel free to post here, and I will try to answer. My background: I am a Professor for Electrical Engineering at Zurich University of Applied Sciences in Switzerland. So far, I don't have any Homepage and Links to Brushless pages (actually, I have some links, but they are written in German).

Yours
Roland

Hey, thank you again! This is a very generous offer. Welcome to the ES forum. You can subscribe to this thread to be notified when someone replies/posts to this thread. It will be easy for you to then track any new post and "open" the new post directly from your email notification. Look for the Subscribe Topic link at the bottom of this webpage...

I'm putting in an order for your book. I am not educated about electric motors & want to learn all the basics I can. Your book looks to be a perfect match to start with. Plus, you can then respond here to any questions.

[Miles]

So if there is anybody, who has questions about the brushless technology, feel free to post here, and I will try to answer.

Hi Roland,

I've just received a copy of your book 10 minutes ago and already I have a question...

Following up on this post viewtopic.php?p=566255#p566255 and with reference to page 44, where you deal with this, you write "The depth of penetration is therefore approximately 2mm.......... In the case of a wire diameter of assumed 0.4mm, one would notice this."

I naively assumed that, unless the wire diameter exceeded double the skin depth for the specific frequency, the increase in resistance would be pretty minimal. If this isn't the case, is there a simple way that we can quantify it?

If you want a specific example, the copper windings of the axial flux motor I'm hoping to build has cross-sections of 14mm x 0.7mm (coils) and 3.25mm diameter (links) - nominal commutation frequency is 533Hz. [Ref. viewtopic.php?p=559971#p559971].

[Roli]

Hi Miles

The current density J = Jo * exp (-x/penetration depth), where x is the distance from surface of the conductor, and Jo is the current density at the surface. With the example in the book, in the centre of the conductor, at x = 0.2mm (with the diameter of 0.4mm), assumed a commutation frequency of 1kHz (which means penetration depth with copper of about 2mm), the current density is Jo * exp (-0.1) = about 0.9 x Jo. at x = 0.1 (a ring with a diameter of 0.2mm), J = about Jo x 0.95. This means, that for this example, the total resistance of the coil is augmented by about 5%. This is not much, but if one wants to construct motors with very high efficiency, then it is worth to consider that. In the formula for the efficiency of the motor (Chapter 3.7), the coil resistance is part of the formula. The larger it is, the lower is the efficiency.
For your example with smaller frequency and larger diameter, you can do similar calculations (calculate penetration depth for 533 Hz). The effect is not very large for the brushless motors, but it is measurable.
Of course, there are also very practical reasons, why one takes several thinner conductors in parallel instead of one. It is then easier to wind the coils.
Yours
Roland

[Miles]

Thank you Roland. That was exactly what I needed to know.

[mimoose]

this is so cool! to have a real, actual mr smartypants we can ask questions about this subject! hurray! i just hope he sticks around for at least 4 months when i will be ready to ask questions.
i would love to build my own hub motor. i confess i was supposed to have learned it is school. but i never really learned it and i forgot everything i didnt learn.
working on a project like this will help me develop my weak electronic/electrical muscles tremendously. does this forum have a thread subscription thingy?

[kevo]

mimoose,
When you post any reply at the bottom of the page are five option check boxes. The last of the five is labelled: "Notify me when a reply is posted" which will subscribe you.

OTOH To avoid getting emails, don't choose notify and just "View your posts" after logging in.