Nikola Tesla You have to watch this

[ringer]

The way you hatched the colour in, it looks like the red coils are wound the wrong way.

 

[Knobhead]

Yeh, right OK!

I try my best and what happens.....

I can see your point though but trying to put it right is like trying to plat fog with the drawing package I've got.

But do you think the theory is right?

 

[ringer]

I guess your theory is correct and it is backed up by articles on the net, but then I am not an expert. I would have thought that building shaded poles would be a costly way of doing it. What about adding some capacitance on the supply circuit of one of the phases to start the motor, then removing that capacitance once started?
Before any such control was added to the motor, perhaps they just mechanically started the motor in the required direction?

 

[Knobhead]

Two phase didn’t last long commercially, it was used a bit in Buffalo NYS. Soon superseded by three phase thank god. So with it’s short life not a lot of info around.

 

[Silly Sausage]

Re: Rotation of 2 phase motor...

Had a think and come up with this... (borrowed your drawing Tony)



2 phases 90[SUP]o[/SUP] out from each other.
If p1 is connected to coil A, p2 to coil B & neutrals out from C & D then the flux peak will rotate clockwise, motor runs clockwise.
If p1 is connected to coil A, p2 to coil D & neutrals out from C & B then the flux peak will rotate anticlockwise, motor runs anticlockwise.

(Prepares to be ripped to shreds...) :38:



edit, still think this is wrong though!

 

[RogertheBodger]

This has just about done my brain in!

It’s the only way I can think to get a two phase motor to run in a set direction.

Now don’t forget the original two phase systems used four wires.

The yellow in the drawing is the shading pole. A single loop of insulated copper embedded in the pole face. Blue and red being the phase coils.
View attachment 11549
Any other suggestions gratefully received, however inane.

The rotor is probably totally wrong. I pinched it from a drawing I was doing for three phase motors

Hi Tony

Interesting question, been giving it some thought (and some reading on the net) and what I think is that Tesla developed the ‘Rotating magnetic field theory’ and using this he built a generator, and a two phase motor, I don’t know how he excited the generator but once it was going and the motor connected, the motor just followed the rotating field around.

Way back then he probably didn’t care which way it was going, as long as it was going, to reverse direction he probably swapped the connections or ran the generator in the opposite direction.

I should imagine it was a lot later, when the idea was more developed and the motor being put to practical use, that he needed to worry about how to fix the direction, maybe he thought about a starting winding later, or maybe someone else did, I've read that he sold the patent to Westinghouse for $65000.

So I don’t think that the motor in your excellent video was capable of running in a fixed direction, but then it wasn’t supplied from a networked power supply.

 

[Knobhead]

Now you’ve got me thinking. Going to have to superimpose two sine waves 90° out of sync with each other.

Found a better way.

Blue (N) and Purple (S) Phase 1
Red (N) and Green (S) Phase 2

The length of the bars represent the strength of the field. So yes you do get a rotating field.

That’s chucked all my theories out the window.

View attachment 11615

So the motor drawing should be like this

View attachment 11616

 

[Silly Sausage]

My brain hurts now :dizzy2: and I'm tired from trying to resist replying to another thread this afternoon.
Work it out so I can stop thinking about it!

 

[Knobhead]

Archie, you are right, I'm wrong.

Stop sulking!

 

[Silly Sausage]

Well, that's a completely useless piece of knowledge I've gained there!

Good thread Tony, bring on the next one.

 

[Des 56]

Will this unsung great mans site become just another Wallmart
It seems a shame that all physical trace of his work will likely make way for potatoes and cabbage

Where's that euro millions guy when you need him lol
Help me raise money to buy Nikola Tesla's old laboratory - The Oatmeal

 

[Silly Sausage]

Will this unsung great mans site become just another Wallmart
It seems a shame that all physical trace of his work will likely make way for potatoes and cabbage

Where's that euro millions guy when you need him lol
Help me raise money to buy Nikola Tesla's old laboratory - The Oatmeal

That's no way to talk about Americans!

 

[Geordie Spark]

I'll buy you a crate if you get a 1st!

I'll help him drink it !!! :17: