Tinman's Rotary Transformer

[tim123]

@ Tim-Quote: and it'll be hard to make a motor which is significantly better than standard.

I think we would need to test an RT against a * non-modified motor of the exact same type * for a proper test.

When I say significant - I guess I mean 10%-15%... Maybe I'm just being too conservative. Maybe it'll be 50% better straight off...

One potential problem with the RT is that you can only fit so much copper on the stators. I think more would be better...

I'll have a look at, and think about the Wankel PMM...

PM Motor:
- yes the PMs magnetise the passing rotor segments.
- there would be cogging in a symetrical motor
- it would prob. be best built similar in design to an Ecklin-Brown generator.
- I'm trying to generalise the principle, by coming up with other designs that use it.
- If I can't think of any better ones, I'll (eventually) build this.


Tim

[tinman]

Ok,here is the first run of the new RT.
Oh,and how to take a resonably accurate P/out from a pulsed output.
http://www.youtube.com/watch?v=0wIwa_kEhOY

[tim123]

Rotary Transformer Test Results

I've run a series of tests on my vacuum-cleaner RT... It has a fan connected - so it has a physical load.

There's only a small range of speeds at which the effect is evident - at the lower range of the motor. This is probably due to the 10w LED I'm using as a load. A fast diode alone would be better.

Note, my diode bridge only seems to be giving half-wave output. So that applies to the results below. And I can't do the math for AC (yet) - to see it's relative efficiency TBH...


Test 1 - Rotary Transformer Configuration

To obtain a 43Hz Running Speed:

Plain DC - No Load on Stator:
- 13v
- 1.33a
- 17.3W

Plain DC - LED Load:
- 12.1v
- 1.26a
- 15.25W

Rectified AC - No Load:
- 23v (peak)

Rectified AC - LED Load:
- 22v (peak)


To obtain a 60Hz Running Speed:

Plain DC - No Load on Stator:
- 15.3v
- 1.40a
- 21.4W

Plain DC - LED Load on Stator:
- 14.9v
- 1.33a
- 19.8W

Rectified AC:
- load did cause a speed up, but only slight.


Test 2 - Standard Configuration

I returned the wiring to it's original state...

To obtain a 43Hz Running Speed, with Plain DC:
- 14.9v
- 0.57a
- 8.5W

To obtain a 60Hz Running Speed, with Plain DC:
- 19.8v
- 0.61a
- 12.1W

Conclusions

- The RT configuration, certainly for my motor, is less efficient than the standard config.
- The output from the 10w LED is perhaps 3-4 Watts, and doesn't make up the difference.
- I can't draw any conclusions from the use of rectified AC.
- The RT does demonstate a Positive Lenz-Effect...

Also, it's interesting to note that the motor runs much smoother in the standard configuration:
- the rotor is suspended by the constant stator fields.
- the brushes have fewer amps going through them.

[tinman]

@ Tim
Good testing there,and some great comparisons.
What we are realy looking at here,is the effect itself. Like we have both said,it could be designed to be far more efficient at using that effect. Even with the motor in standard series conection,we can get the same effect,in that we can draw power from the stator coil's without it effecting either the P/in or the torque of the motor.
So give it a try.place your LED across the stator coil one way,then the other. If i series connect mine,ofcourse the current draw go's down,due to the higher resistance value of the series conection.You also have an electromagnet in way of the stator core aswell,so rpm and torque will go up. I can still then draw power from the stator coil,while dropping the P/in.
The problem we have,is that the motor was designed to run in the series conection. Now what if the motor was designed to use the effect we have gotten?. More turns of wire on the rotor would drop the current draw,while maintaining the field strength.
You can also catch the inductive spikes on the input,and put that power to use aswell.

But the main goal was to see the effect,and work out how to use that in a motor designed for the effect to be maximised.
I guess you could say we are running a gasoline engine on diesel. Now by placing a large cap on my FWBR,the motor dose indeed speed up,and i get more output from the stator coil. But the P/in voltage also climbs from 22 volts,to 36 volt's,while dropping only .2 of an amp once the motor speeds up.
Tomorrow i will be setting my generator up on the motor,and doing some P/in  P/out testing.
I will post the result,and also the video showing the test.

[tim123]

Thanks TM
  the testing has made me realise how beneficial a permanent-magnet stator field would be for the motor - as long as it doesn't affect the magnetic circuit of the stators.

The diagram below is for discussion purposes. The idea is to include a pair of PMs to provide a nice strong field for the rotor to turn in, but without connecting them to the stator's magnetic circuit. So the * change of flux * seen by the stators is unaffected by the PMs - whereas the rotor is very much affected by them.

Also - to maximise that change in flux seen by the stator, I think it would ideally cover just 3 rotor segments. Then it goes from NNS to NSS etc. The flux change is then 1/3 of the total, and it has one segment to pull, and one to push at all times with the positive-lenz effect...

PS - Other things that may help optimise the design:
- As you said - more turns on the rotor, or even a bigger rotor in general - with much more copper.
- Much bigger stator coils. More turns = more volts = more turning force!

Correct me if I'm wrong, but I think the bigger the stator coils, the stronger the effect will be...

It's possible that OU is just a matter of stator size... Because the lenz-force is positive - we should be able to take as much off it as we like, and it'll just help...

Huge stator coils will cause a huge force - by Faraday's law - detailed previously.