Tesla Car and his nephew

[Magluvin]

Most likely it is best to start with a motor as a load. An AC induction motor, as claimed in the stories.

I think Tesla used a modified motor. Maybe not but just thinking.

Since it is AC, there should be a freq we could get it to resonate at with proper capacitance added, via external or bifi capacitance within the motor. Tesla knew he could get capacitance in the windings right where it needs to be.

So once one gets the motor to run on minimum input then proceed with developing a driver. The driver maybe doesnt need tubes. Maybe there are 10 ways it could be done. Maybe the tubes are more efficient at doing it, maybe not.

Tesla was all about efficiency. I would be willing to bet that he made sure he had the most efficient motor he could devise at the time, this reducing the need of a driver that would have to provide power to a 3ft long by 2ft 80hp ac induction motor. ;] A lot of the ones we have today(ebay shows many varieties) seem just about that size for 80hp

It is possible that if he didnt use a modified motor that his driver might be much more than a box under the dash with 12 tubes, etc.

Maybe there is something to learn from in his motor patents.

Ive read that AC induction motors took a left turn in how they were made at one point as to make them not easily modified or converted. Less possibilities for resonance.

What was it, rotoverter? that they would add caps to make the motor put out about as much with 110vac as it would at 220 or 330?  Id have to look it up again. Some vids out there. Im sure there is room for further improvements.

Just thinkin.  ;]

Mags

[Magluvin]

Ever see one of those small AC fans in a microwave oven? The same that were used in phonographs to drive the turn table.  Ive looked for info on just how they work. There isnt that much about them. Maybe Im not the best searcher. ;]

The armature is solid I believe with what seems to be a combination of copper and iron made in diagonal sections. Then you have the stator in a U shaped core with the input coil, of many turns, wound toward the bottom of the U. The inner side of the left and right legs are shaped to fit closely to each side of the armature.

The part I hadnt found an answer to is the shorted copper turns of large gauge wire that somehow bridge the small gaps between the left and right legs.

If you have seen one then you know what Im saying.

Im going to dig out my microwave fan and look into this more.

When I try to imagine Tesla using the coils in motors as part or whole LC  circuits, I remember trying to get that lil motor to do some ringing, but didnt have much luck. So Im wondering if those shorted windings impede the ring I tried to get. Maybe I was doing it wrong. 
I figure that those shorted windings must have something to do with causing a phase shift and or producing its own field as a function to get the rotor to spin. I think.

Oh well, Ill look at it here in a few days when I get the motor out of storage. Im working off and on on 3 projects, but always room for something fresh. ;]

I figure that it is an AC induction motor that can be easily had for all to experiment with, if they are interested in this topic.  If you can do it small and cheap, the big expensive will come. ;]   learn to understand the AC motors.

Then there are things to try. open the shorts to see what happens. Try different size wire and more turns. Connect them to each other! lol  I dunno, be creative. ;]  Bifi the input coil. Or connect a cap across the input coil as a stand alone lc then wind a few turns of thicker wire around the original winding and discharge caps into that. All Tesla stuff as ingredients.

Anything that MIGHT make it run better. Who knows. ;] It can be a beginning for this thread. A project.  If someone wants to try larger motors, just be careful. ;]

Mags

[sparks]

The motor your describing is an induction motor.  The heavy copper turn is shorted.  The current induced in this coil lags the line current.   This first shades the magnetism in that portion of the pole face and then due to its current lag makes the steel it surrounds more magnetized than the rest of the pole face. (all within a 1/2 cycle).   The rotor sees a magnetic pole shift from the unshaded towards the shaded portion of the stator.  The generated currents on the rotor cause magnetic poles in its steel that try to catch up to the apparent rotating magnetic field produced in the stator.  It's called a shaded pole induction motor.

[Farmhand]

Hi Magluvin, I had a play with one of those with the idea of using one for a rotary spark gap motor. Interesting little motors, I think they are "shaded pole" motors.

Just a couple of notes I made without series driving caps big reactions occur back to the low voltage winding of the supply transformer.
If the frequency is raised to high for the winding the power input drops off and so does shaft power, I found at 200 Hz I could easily stop the shaft at that stage there is less 12 watts input, they are designed for 60 Hz the original windings are high impedance obviously. Good things I noticed was that if the frequency increase is small and instant the motor shaft speed increase is almost instantaneous (without slipping) providing the motor is not overloaded. And they are synchronous with the supply.

here's the video  http://www.youtube.com/watch?v=HPli7vKSwEY

Just thought I would share incase it helps.

Cheers

[Magluvin]

Hey Farmhand

Thanks.  Shaded pole.  I have heard it so many times and never thought about it. I just looked up wiki and it seems to make sense.  It said triac variable-speed controls would work for your motor.

I had a few record players when I was a kid. Never took interest in exactly how they worked or ac motors in general. Was a dc kid. ;]  But now I have interest.

Thanks for the thoughts and info.

Maybe if you rewound the coil with larger wire and less turns it might work at higher freq. 

Ill get the one I have and try some things. I wont break the shades. 



Mags