Storing Cookies (See : http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm ) help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
https://overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please LEAVE this website now. From the 25th of May 2018, every existing user has to accept the GDPR agreement at first login. If a user is unwilling to accept the GDPR, he should email us and request to erase his account. Many thanks for your understanding

User Menu

Custom Search

Author Topic: Dia. Mag. Alternator  (Read 190186 times)

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #180 on: May 10, 2011, 01:24:20 PM »
I fitted the new driver ring plate this morning.  I pulled the old driver ring pins replaced them with 6 inch pieces of 1/2"-13 threaded rod.  They use the same holes as the feet of theDiaMag6 alternator.  There are no heads on the rods so I needed to improvise some feet.  I used a flange nut as a foot, and a regular nut as a jam nut to keep the feet in place.  This acts as a leveler too.  I am going to have to do some adjusting to get the threaded rods to act like driver ring pins...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #181 on: May 26, 2011, 04:17:55 PM »
DiaMag6 is now my Beast of Burden for UABMM2 over on that thread.

Back to DiaMag7 and the sharp sheet metal edges.  I was fretting over having to chamfer the slots for the wire, and I was kinda stuck there.  Inspiration comes in the strangest places.  I was on the way out to the garden to get some things for my salad; radishes, garlic, and cucumbers.  I walked past the alternator from the Savage Salvage thread, and just happened to look right at the windings, and also the solution.  Its a Chinese alternator.  The windings have a casing, like an isolator which looks like its a sheet of plastic.  They wind the coils, and then fold the sheet of plastic into the slot, and press fit a piece of bamboo in there.  It might be a chop stick!  Genius!

So, I found some relatively thick plastic sheeting.  Vinyl, about 16 mils thick.  I don't need to pretty finish the winding slots.  I can get them to an acceptable shape, and then put a little sheet of vinyl in there to protect the wire from the metal edges.  I was thinking about buying some of that Super Poly-Thermaleze magnet wire, and its expensive, like $65 for a pound.  I guess my sub-conscious was looking for a way not to spend that $65...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #182 on: May 26, 2011, 05:08:59 PM »
There, I had to make 16, and get them installed...

Ready to Re-Wind...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #183 on: May 26, 2011, 08:55:41 PM »
The DiaMag7 is another step towards what I want to do, but to make more power I need more windings.  I also want a larger diameter rotor, with more poles so it doesn't have to rotate as fast.  With two poles I'll have to spin the shaft at 3600 RPM to make 60 Hertz.  When we add poles we can divide down the shaft speed.  With 4 poles we only need to spin the shaft at 1800 RPM.  With 8 poles we would only need to spin the shaft at 900 RPM...

With a monolithic magnet we can only have two poles.  Large diameter (2, 3, and 4 inch) monolithic magnets are very expensive.  A 2 inch Diametrically Magnetized Ring Magnet at K&J is $180.  A little costly for my prototype...

http://www.kjmagnetics.com/proddetail.asp?prod=RY04Y0DIA

Been looking at various rectangular magnets thinking that I can get a thin magnet that won't have too much radial tolerance, but, you know, its a flat, and I need a radius.  Finally I found some radiused magnets at Magcraft.  To build an 8 pole, 2 inch outside diameter rotor will cost around $50 for the magnets...

http://www.rare-earth-magnets.com/p-36-nsn0625.aspx

I got a piece of round aluminum stock from MSC to fill the inside space.  Its 1.75 inches outside diameter.  So the radiused magnets should fit neatly around the aluminum roller.  Now I need to draw the stator and bearing brackets, and get some aluminum sheet on order...

https://www1.mscdirect.com/CGI/NNSRIT2?PMPXNO=4451647&PMTERM=02629459

It took me a while to find these, searched lots of different places on teh interwebz.  Magcraft had the perfect match for my next alternator, the NeoMag8.  I did change the name there.  the DiaMag alternators were based on a diametrically magnetized monolithic magnet.  With the radiused segments, we now have a compound rotor, and not a monolithic structure.  So I changed the name to reflect this.  Now its NeoMag for Neodymium Magnet Alternator...
« Last Edit: May 27, 2011, 03:56:52 AM by z.monkey »

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #184 on: May 27, 2011, 03:44:55 AM »
Managed to rewind about 3/4s of the coils...
Two windings, 90 degrees apart...
Blarg, tired...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #185 on: May 28, 2011, 12:20:16 AM »
Finished off the windings.
This time the slots are full.
The first wind had about half the slot.
Its really light, about 10 ounces.
DiaMag6 weight 10 pounds.  LOL!
Time to build a test bed...

Cap-Z-ro

  • Hero Member
  • *****
  • Posts: 3545
Re: Dia. Mag. Alternator
« Reply #186 on: May 28, 2011, 12:50:45 AM »

*watches with keen interest*

Great build z.

Regards...


z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #187 on: May 28, 2011, 01:21:52 AM »
Hahahahaha, Fork Yeah!

The coil develops 2.2 Volts, and there is current behind it this time.
I light one bulb 2.2 Volts.  I light 4 bulbs 2.2 Volts.  The coil is 1.6 Ohms.
Some of that is DMM error, like 0.6 Ohms.  So as measured I can drive
1.375 Amps, and is probably more like 2 Amps.  So its somewhere between
3.0 and 4.2 Watts, about 6 to 8 times more power than DiaMag6...

Oh yeah, only one winding is hooked up...  2X in the near future...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #188 on: May 28, 2011, 01:59:41 AM »
Great build z.
Thanks Cap-Z-ro...
It took me a year to make 3 Watts...
I hope this is an exponential curve...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #189 on: May 29, 2011, 11:49:51 AM »
Got everything mounted to a test block.  I used a couple of Full Wave Schottky Bridge Rectifiers to rectify each coil.  Then connected them in series.  2.2 VAC on each coil, added, then subtract the diode voltage drops.  The result on the load is 2.7 Volts, bulbs are brighter.  The total diode Voltage drop is 1.7 Volts.  So, 0.425 Volts each way, times two full bridge rectifiers.  I selected the Schottky diode because of the low forward Voltage drop, but also because they a high current parts, one Amp continuous, 25 Amp surge.  Now I am utilizing both coils, and I can see how much current I can drive.  Also thinking that the wire I chose is too big, and I need to use 24AWG or 26 AWG to get the Voltage up.  Maybe, not by unwinding this one again, but make another one.  The labor on the DiaMag7 is a couple days, while replicating the Iron Stator on DiaMag6 would take a couple of months.  I need to do some more testing, find heavier loads...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #190 on: May 31, 2011, 01:25:02 AM »
OK, I have some preliminary numbers from test.

Open circuit Voltage per coil  2.47 Volts AC.

DC Open Circuit Voltage (Both coils rectified and added)  4.30 Volts DC.

1 Bulb Load Current  69 milliAmps.

1 Bulb Load Voltage  3.2 Volts DC.

4 Bulb Load Current  200 milliAmps.

4 Bulb Load Voltage  2.6 Volts DC.

4 Bulbs + 5 Ohm Resistor Load Current  285 milliAmps.

4 Bulbs + 5 Ohm Resistor Load Voltage 1.8 Volts DC.

With these numbers you can start to see how much of a load we can handle.  At half an Amp the Voltage will go down to a Volt.  So, you can see we need more windings.  I am still using my drill to drive DiaMag7, 1400 RPM, 23 Hertz.  We would have better performance numbers if I could run the shaft faster...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #191 on: May 31, 2011, 02:02:17 AM »
Lookz at teh numbers...

1 bulb test = 0.22 Watts
4 bulb test = 0.52 Watts
4 bulb + 5 Ohm test = 0.51 Watts

We're using the same 1" inch Magnet...

DiaMag7 peaks at 0.52 Watts...

Its Rotor Dynamics 101, our power output is limited by the Rotor Physics.
We have a small section of Pole on each side, maybe 30 to 45 degrees.
This is all that is influencing the coils, the other 270 to 300 degrees of
the Rotor is wasted.  Hence the concept of a multi-Pole Rotor...

What if my coils are improper?  Should each slot pair should be an individual coil?
Maybe each individual slot coil should have its own rectifier.  Then the rectified power
could be combined in a series parallel configuration to produce the desired
output.  All parallel configuration for Current, and all series configuration
for Voltage, or a combination, but that's a lot of silicon...

Perhaps each slot should be the width of the polar influence, and that is all.  Then
we could determine the number of slot pairs based on the Poles radial width...

This allows the limited Pole space to be utilized more efficiency, by segregated slots...

Also, this begs the application of a multi-Pole Rotor, probably to much expense...

loosecannon

  • Jr. Member
  • **
  • Posts: 57
Re: Dia. Mag. Alternator
« Reply #192 on: May 31, 2011, 04:30:26 AM »
z monkey,

still watching this and your mag motor thread with much interest.

if you are looking to spin the alternator faster, how about a trim router with a rheostat?

should be much faster than 1400rpm.
LC

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #193 on: May 31, 2011, 12:01:24 PM »
The Dremmel tool I have is rated at 30,000 RPM.  That's 500 Hz...
500 Hz. is the limit of an Iron transformer, but the DiaMag7 has no Iron.
Theoretically we can do this, but the winding strategy is wrong at this
point.  I'm going to cut another set of plates, this time on the Palmgren
table, and make DiaMag7-2.  This time with 8 individual coils, 26 AWG
wire, and 8 Schottky rectifiers.  The Voltage should go up due to the
smaller wire.  The Current should go up because of the individual coils
and rectifiers...

A quick note about my coils.  The Poles are only affecting the coils partially.
As it is now, each coil covers about 75 degrees of the radius, but the
Pole is only affecting part of the coil, 30 degrees maybe.  This limits the
potential Voltage because the coils need the Pole currents to make Voltage.
If the coil is wider than the Pole Field, then the extra windings are just
transporting current and not making Voltage.  So, we need to make the
slot coils wider, preferably the width of the optimum Pole currents, and isolate
it from the adjacent slot coils with diodes.  The Voltage will increase because the
slot is wider, and the wire is smaller providing more windings per slot coil.

Gotz to make another drawing.  I have a 3/32" plate, 0.09375", that
I have been planning to use for the next revision.  So it will be, basically,
the same mechanical construct with an electrical modification.  Then
I can adapt my driver spider to fit the Dremmel Tool.  The shaft coupler
set I have has multiple shaft sizes, and I can probably adapt something
that can fit into the Dremmel Tool's Collet...

z.monkey

  • elite_member
  • Hero Member
  • ******
  • Posts: 1660
    • Scientilosopher's Domain
Re: Dia. Mag. Alternator
« Reply #194 on: May 31, 2011, 06:57:02 PM »
OK, here's the next one, DiaMag7-2.  The slots are wider, went from 0.9375 inch to 0.125 inch.  Also the slots are deeper, went from 1/2 inch to one inch, might not be able to fill them all the way, which is alright.  There are 8 independent 26 AWG coils, and they are spaced 20 degrees apart.  The mounting tabs get 30 degrees of the radius each.  The mounting tabs have been a continuous problem because they are in my winding space.  On the next one, NeoMag8, I will change from outside slots to inside slots to correct this annoyance.  All non-ferrous construction, like the DiaMag7.  Next marking the plates...