Confirming the Delayed Lenz Effect

[TinselKoala]

Well you sold me on it Tinsel, I'm gonna get one now. Any suggestions on the actual chip or start up kit I should get ? Is there USB interface, or just serial ?

Anyway I think you'll like my next video clip, I got it really thumping, it's kinda deceptive the sound doesn't match the speed kinda thing, but the tachometer jumps in the hundreds of revs. The capacitor C2 has a Sine wave on it that Matches the input pulse just like a Tesla coils wave forms, the pulse is less than 50% but the square side of the drain wave form matches to exactly the down slope of the sine on C2 kind of thing, like my Armstrong oscillator variant's wave forms.

The timing now is now almost automatic over a certain range due to the way the coils are oriented to the magnets but some auto adjustment would be very helpful. I can use my micro to switch the power to the coils off if a certain drain voltage is reached ect. as protections, which can be used to limit speed kind of.

Video will be about 15 minutes, it should be good for a laugh at my hot glue skills when prototyping.  I need to try that coil at a few degrees either side of 45* just to make sure I'm doing the right thing with the main build, it could have two motor coils and a single charging coil with two appropriate windings on it, the charging coil will be between the two motor coils so only the bottom 90 degrees of the rotor would be used for driving, (like a cradle). A 90 degree tripple, or I could make it two sets of coils on each side so two 45 degree N-S twin coil set ups that way. Dunno yet. If the testing shows me 45* is actually the best then it's a go ahead on something. I want some open space on the rotor for experimenting and to keep it upright and bottom heavy, I'll have to set up a rotor balancing device as well.

It's  really a lot of fun. I'll need to get hall's i've never used them, sounds good though.

Cheers

Arduino clones are made by many different manufacturers but the hardware specification is followed by them all so they are mostly exact equivalents. I use the OSEPP brand and the Uno model for most of my stuff, although I also have an OSEPP Mega, the larger faster version with a lot more IO ports and RAM.
I would suggest getting an Uno, which will have the Atmel ATMega 328p chip and the USB interface. I bought the OSEPP brand because it is carried in-store at the local Fry's; you may find other brands to your liking, but the basic Uno of whatever Arduino clone is what I'd suggest starting with. Other models might have faster processors and more hardware interrupts but I don't think these are necessary for the pulse motor.
http://osepp.com/products/arduino-compatible-boards/osepp-uno-arduino-compatible/
http://osepp.com/learning-centre/start-here/osepp-arduino-basic-companion-kit-start/
You can download and look at the Arduino IDE here:
http://arduino.cc/en/Main/Software
If you are using Linux, as I am, the installation is easier than what's described for windows in the links above. It just installs and works, from the Ubuntu package manager. The IDE comes with many example sketches (programs) that you can look through, and there's a complete command reference at the arduino.cc site.
I don't have a pulse motor built using the Arduino but here's my video example of sensor position detecting, with precise, adjustable timing, switching a heavy coil thru an external transistor:
http://www.youtube.com/watch?v=1pHDi9UvBOU
http://www.youtube.com/watch?v=xkiGTWODERo

BTW, I love your builds and your documentation and your careful work and thought process. I think you are a great example to other experimenters here... and to me as well. Thanks for sharing your work!

[Farmhand]

Here's the first video link so I'll link the two video's together here, the first video gives an explanation of sorts, if my mumbling can be understood, the problem is I think ahead of my talking and stumble on my own words. 

Video 1 Cicuit explanation
http://www.youtube.com/watch?v=IndhigMm2Bs

Video 2 Test Run.
http://www.youtube.com/watch?v=aC5Hdp6LSMU

Thank you very much for the links and the tips and help Tinsel much appreciated, I can spend wisely now. Using the same hardware as most others will be helpful.

The thing with the fan load is that at low rpm the fan is not much load but at higher rpm the motor must work harder for smaller gain because it takes more work to get from say 1800 rpm to 1900 rpm than it does to go from 1600 rpm to 1700 rpm.

I'm thinking I could use a squirrel cage on the extended shaft with magnets put into the squirrel cage so I can mount a four pole stator around it then I can switch the generator coils in series with the supply capacitor for regenerative purposes.  Hopefully it could act as a brake by switching the coils in with a mosfet. A test load apparatus as well, built right in on the shaft and there would still be room for a belt/gear or pulley on either side. I used an actual fan shaft and squirrel cage to make my rotor they are 8 mm so the roller skate bearing fit snug, the spacers are rattling though.

Cheers

[TinselKoala]

Great, Farmhand!
Re fanload: As we found out in the Yildiz thread, you can get pretty good shaft power estimates if you use a known load like a model airplane propeller. Believe it or not, the aerodynamics of these things are researched and known to fair accuracy because at the higher levels, it's a competitive sport. You can get suitable propellers for small cost, you can stack them together to make multi-blade loads, and you can know the shaft power dissipation simply by knowing the stable RPM reached by the prop, your local air data parameters, and some number crunching.
http://adamone.rchomepage.com/calc_thrust.htm
Check out all the different propellers in the "prop type" pulldown.
The power dissipation of a fan or prop goes as some power of the RPM (like square or third, I can't remember) so the faster you go the harder it is to go faster.

[Farmhand]

I see yes model airplane props would have to be tested for specs or rated on known principals. Good idea.

Here is the small generator I modded from a shaded pole motor, I left the shading bars on the small tryout one but I'll also try it without them. It has two north poles in a row and two south poles so it's basically a two pole generator it make nice sine waves too. You can see how I cut the joined parts of the core around the rotor to separate the poles to the sides and make gaps. With the bigger one I'll make rows of North then south magnets following the curves on the rotor to minimize cogging, cogging is lumpy in the little one but it spins up and generates sine waves.

Basically it make a generator kind of like this Tesla design below but with four permanent magnets on the rotor. As well is a picture of the bigger motor I intend to modify, it has 0.5 mm or so wire 480 mH and not much resistance the rotor is wide enough to take a row of magnets following the curves. And a pic showing how I made the rotor from a cutting board and old fan, I chewed the recess out of the bit of wood to take the optical sensor, hahaha.   


Cheers

[MileHigh]

Farmhand and TK:

If anybody ever goes the microcontroller route to generate the pulse timing based on the measured RPM of the rotor that would be really cool.  If you looked at that LED hard drive clock clip, it's really impressive how when he slows down the rotor the pulse timing remains dead-on.  Note that even for your current builds, just having a separate transistor to switch on some LEDs to see the pulse timing relative to a white painted-on line (White-Out) on the rotor magnets may be interesting.  You don't have to use it all the time.

I actually haven't had a chance to look at Farmhand's clips yet.  For the "Pulse Motor Build-off" you can check with Tinman or ZeroFossilFuel or Russ Gries.  They are the guys that typically organize it and have all of the info.

I am not a "fan" of using a propeller prop as a load because I think the typical pulse motor spins too slowly.  I think the pulse motor driving a generator attached to a load resistor is the better route.  During the Yildiz fiasco a very good suggestion was made to use two bathroom scales.  With a smaller pulse motor using two digital scales might be perfect.   All that you have to do is measure the RPM and the weights on the scales (assuming a pulse motor with a horizontal axis) and crunch some numbers and you will be able to measure the mechanical power output of your motor in watts.

MileHigh