Muller Dynamo for experimentalists

[plengo]

Hi all,I have question romerouk pulled rf chokes from equipment and used the core
from the choke.Is the choke the same as sold by radio shack?Does the core fit thru the bobbin
with out either boring the bobbin or using a dremal tool to shave down the core.
If he did have to make the
core fit which method did he use boring the bobbin or shaving the core or both.

I tried the choke from RadioShack and the bobin and it fit perfectly. I used two bobbins for this picture where I cut the ends of each bobin. CORRECTION: it is magnetic  (wrong: The core is also not magnetic which IS GREAT).

Fausto.

[tysb3]

http://www.youtube.com/watch?v=0leZLxHgST0

one more about shorting coils:

[plengo]

Yesterday I got my new coils using Litz wire. They are 0.125mm each strand, 7 strands, total diameter around 0.375mm. The wire seems perfect. I bought it from http://www.surplussales.com/Wire-Cable/LitzWire.html item "(WHS) LW-7/36" group B. It is a gigantic spool that easily I could build 500 of those little bobbins.

I did not worry about how many turns it took. I only concentrated on making all coils as close as possible to 3 ohms. They look very alike Romero's coil so I guess Romero did not measure his coil correctly (which I doubt) or he mention the wrong number or turns. There is no way one can fill those 6mm x 10mm bobbins (internal dimensions) to the edge and still be less than 2 ohms.

I also changed my shaft and bearings. Now I am using a threaded rod for the shaft where I can control the distance of the rotor from the coils with easy and more accurate. Also it is much easier to work with small bearings. I guess my 12mm rod shaft idea will be postpone for when this becomes a larger motor.

Cores are from RadioShack http://www.radioshack.com/product/index.jsp?productId=2103978. I removed the wires and cut the core in half. They fit very tight inside the bobbins. So it is good to use a drill to enlarge just a little bit the center diameter of the bobbin and all fits perfectly.

edit: I forgot to mention. Inductance is around 1.2mh.
edit 2: No core is 0.45mh with core 1.2mh. No magents.

Fausto.

[baroutologos]

Welll done plengo. Just keep going

[plengo]

Tonight I run my replication using ONLY 2 driver coils and no generator coils installed.
The first thing I noticed is that those little coils can give a nice punch to the rotor and spin it really fast.

This is just a test run. I am using Arduino Duemilanove as multi pulse driver so that I can have more control over the pulses, and timing. I am using a hall effect.

At 3 pulses, 6 volts and around 300 to 400 ma I can spin this thing to 650rpm easily. The very interesting thing is that it will start slow than current consumption will go up to around 450ma. Than as the speed increases it will drop current to 300 and continue spinning faster and faster. Almost like switching shift in a car as the car increases its speed.

Spikes on the coils are above 250 volts. There is much more to this little bobbin coil and magnets than one would think. Attaching load to the DRIVING coils will actually help a lot in speeding it even faster for a mere 20ma increase. Very interesting. Imagine when I have all the gen coils doing that?!!!

This motor is very exciting because it is not behaving at all like an SSG or window motor or Adams. There this funny "banging" sound that magnets are causing as the speed gets to the point of "needing to switch the gear" and go in higher speed where than the banging gets smoother. As the speed increases it starts the cycle again.

Sometimes the pulsating, as the rotor speeds, misses some pulses and the rotor goes finally to the next "gear" and the whole cycle repeats.

Fausto.

edit 1: one pulse, 12.5v at 300ma, 970rpm and accelerating. Load on the drive coils make no difference on current consumption.