Search found 38 matches

by learningrc
Aug 22 2018 4:27pm
Forum: Motor Technology
Topic: Tesla's Model 3 motor technology.
Replies: 1
Views: 653

Re: Tesla's Model 3 motor technology.

Probably means PM assisted synchronous reluctance (not switched reluctance).
by learningrc
Aug 18 2017 8:34am
Forum: Motor Technology
Topic: Angled Stator Laminations vs Rotation Direction
Replies: 1
Views: 493

Re: Angled Stator Laminations vs Rotation Direction

"Angled laminations" are usually called "skew." The stator or the rotor can be skewed. The main reason this is usually done is to reduce cogging torque. It has no effect on direction of rotation.
by learningrc
Jun 28 2017 2:57pm
Forum: Motor Technology
Topic: New motor design
Replies: 5
Views: 1288

Re: New motor design

Maybe another member can enlighten me about that graph. Not sure why he uses force instead of torque but it doesn't really matter for the point he is making. The 2 force vs angle graphs are a bit different than the standard ones you generally see in the literature but the bottom graph is force vs c...
by learningrc
Feb 06 2017 2:14pm
Forum: Motor Technology
Topic: Magnet motor?
Replies: 16
Views: 2345

Re: Magnet motor?

nutspecial, The physical law it is breaking is the conservation of energy. You can't get more energy out of a system than you put into a system. In the first video you posted, notice that every one of those parts of the video where motion is produced, a human is in some way providing energy into the...
by learningrc
Feb 06 2017 2:19am
Forum: Motor Technology
Topic: Magnet motor?
Replies: 16
Views: 2345

Re: Magnet motor?

I suppose if you started physically moving the magnets while it rotated, it could work. But then you are adding energy into the system, which defeats the supposed point of the magnet motor. What advantage do you think doing it this way would have over normal motors?
by learningrc
Feb 05 2017 10:16pm
Forum: Motor Technology
Topic: Magnet motor?
Replies: 16
Views: 2345

Re: Magnet motor?

Magnet motors are literally impossible. If you had a motor that had permanent magnets on the rotor and the stator, then the most the rotor will turn is 1/2 revolution. It will turn until the magnets are in a state of equilibrium. Actual motors work because at least on of the magnetic fields in the r...
by learningrc
Dec 09 2016 9:50am
Forum: Motor Technology
Topic: Motor Design Software
Replies: 8
Views: 1453

Re: Motor Design Software

Typical software used in industry would be MotorSolve, Speed , RMExpert , JMAG-Express , and YES motor design software . There are others, but those are the main ones I've seen. A lot companies develop their own software. And, of course, in addition to this motor design software, most companies use ...
by learningrc
Dec 05 2016 11:24am
Forum: Motor Technology
Topic: PM Motor theory - formulae etc.
Replies: 71
Views: 44247

Re: PM Motor theory - formulae etc.

If you pair an ideal motor with trapezoidal back-emf with an ideal trap drive and do the math, you can see that the harmonics in the back-emf and the harmonics in the current actually work together to produce torque, not losses. In fact, if you compare an ideal trap motor+drive to an ideal sin motor...
by learningrc
Dec 05 2016 9:53am
Forum: Motor Technology
Topic: FEMM Help needed
Replies: 7
Views: 1032

Re: FEMM Help needed

Well, it depends what you are trying to do but generally you will group the entire rotor into one group. Then you can select the group and then go up to "Rotate" under the Edit menu. The angle you need to rotate it for each step is going to depend on a number of things (number of poles, number of sl...
by learningrc
Nov 07 2016 12:21pm
Forum: Motor Technology
Topic: Asynchronous motors - is induction the new future?
Replies: 76
Views: 18848

Re: Asynchronous motors - is induction the new future?

Ideally the ultimate motor break through would be a magnet that can be electrically increased or decreased in flux strength but still retain a very strong magnetic flux under no volt condition's this could give high efficiency at start up torque and at full speed when torque lags and efficiency dro...
by learningrc
Sep 14 2016 9:49am
Forum: Motor Technology
Topic: Coil Winding Show - Chicago - Oct 4-6
Replies: 1
Views: 326

Coil Winding Show - Chicago - Oct 4-6

For those in the Chicago area, the Coil Winding show is coming up soon (Oct. 4-6) and you can get tickets for free . Besides seeing a whole bunch of cool technology used to manufacture motors, you can also attend talks by Konstantinos Laskaris (Principle Motor Designer at Tesla), Jim Hendershot and ...
by learningrc
Apr 08 2016 4:03pm
Forum: Motor Technology
Topic: Stupid Me
Replies: 5
Views: 709

Re: Stupid Me

It isn't quite right to say that the only thing that causes torque is amps. Torque (in PM motors) is caused by the interaction of the permanent magnet flux with the flux caused by the current flowing in the coils. So torque is proportional to 1) the current, 2) the air gap flux (per magnet pole) and...
by learningrc
Mar 30 2016 8:43am
Forum: Motor Technology
Topic: FOC/Field Oriented Control
Replies: 1
Views: 553

Re: FOC/Field Oriented Control

That lecture is by Dave Wilson at TI. For a more in depth look from Dave, look up "Teaching Old Motors New Tricks" on youtube. It is a set of 5 lectures that really goes into detail. It has some of the same material as this one.
by learningrc
Mar 20 2016 10:39pm
Forum: Motor Technology
Topic: Polymagnet - programmable printed magnets?
Replies: 5
Views: 1057

Re: Polymagnet - programmable printed magnets?

I talked to these guys at a conference a couple years ago. That had a lot of different magnets to play with at their booth. I asked if they had any ideas about how these would be used with motors and they didn't give me much of an answer. At the time, they were somewhat limited on the grade of magne...
by learningrc
Feb 05 2016 1:41pm
Forum: Motor Technology
Topic: Resources
Replies: 27
Views: 24814

Re: Resources

Electric Machine Design Videos by Jim Hendershot.

http://www.motor-engineer.net/engineeri ... endershot/

I've taken a course with Jim and see him at conferences every once in a while. He's a great guy and these lectures are a very valuable resource
by learningrc
Feb 01 2016 11:22pm
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

One last question, because I'm' genuinely curious about your reasoning, then I'm done. I won't even reply to your answer. If you truly believe back-emf is bad and should be minimized, why would you use 52 turns? Why not 1 turn?
by learningrc
Feb 01 2016 9:37pm
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

Browser, I'm going to finally take your advise and stop replying to you. Good luck with your 1 turn, low voltage, high current motor.I hope it does what you want it to do.
by learningrc
Feb 01 2016 9:06pm
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

Anomaly 1: 100VDC, 10A draw, and you cite a resistance of 0.5Ω. But R = V/I, so R should be 10Ω. You are forgetting about the back-emf. V = IR + E. 100 V = 10 A x 0.5Ω + 95 V. That's a pretty elementary mistake to make, IMO. For real motors, that motor velocity constant (and the back-EMF) is determ...
by learningrc
Feb 01 2016 3:36pm
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

Your insistance that back-emf is a bad thing and needs to be minimized is preventing you from understanding why a single turn isn't the best way to wind a motor.
by learningrc
Jan 31 2016 4:43pm
Forum: Motor Technology
Topic: Switchable KV
Replies: 6
Views: 662

Re: Switchable KV

If you have a motor with windings for the field and armature (series DC motors, shunt wound DC motor, etc.) instead of permanent magnets on the field as brushless motor are, then you essentially have a motor that can have adjustable Kv. Provide less current to the field winding and Kv goes up; provi...
by learningrc
Jan 31 2016 4:16am
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

Browser, go download Mevey's paper that Miles linked to. Go to chapter 2, equation 2.40. Same equation that I've given 3 times now. If you read earlier in the chapter to see how he got to that equation, it is VERY clear that e in his equation is back-emf.
by learningrc
Jan 31 2016 3:55am
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

First. learningrc. THANK YOU. Thank you for formulating an actual argument rather than a knee-jerk reaction. And especially thank you for citing some actual text. (Unfortunately, you still ain't gonna like what I'm going to say :( ) These aren't arguments ... all I did here was quote from some text...
by learningrc
Jan 31 2016 3:36am
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

It's been a while since I've read Mevey's paper ... good call, Browser could learn a lot from it. One of the things he would learn from that paper (or the books I mentioned, for that matter) is that the back-emf in a motor is just the derivative of flux linkage with respect to time. And we all know ...
by learningrc
Jan 31 2016 2:48am
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

Have it your way; whilst you cannot have an electric motor without back-EMF; IT DOES NOT mean that "back-emf is fundamental to how a motor converts power". Seriously, pick up Kingsley and Fitzgerald's Electric Machinery . It's a standard textbook for the first course you would take as an undergrad ...
by learningrc
Jan 30 2016 3:52am
Forum: Motor Technology
Topic: Windings: basic questions.
Replies: 276
Views: 21635

Re: Windings: basic questions.

He hasn't even thought it through. If you have diodes on the three legs then in a Wye connection you will get zero current and in a delta connection you might possibly get current to flow through 2 legs but there won't be any commutation it will just lock into place and you'll have a nice heater.