Author Topic: magnets  (Read 3631 times)

0 Members and 1 Guest are viewing this topic.

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
magnets
« on: March 01, 2013, 02:25:54 AM »
hello...im want to make small scale axial flux generator,so i orderd 20mmx3mm disco neo magnets N48,so my question is will this magnets work,im lokin to make 8 magnets 6 coils.....

electrondady1

  • SuperHero Member
  • ******
  • Posts: 2516
  • Country: ca
Re: magnets
« Reply #1 on: March 01, 2013, 06:04:40 AM »
yes it should work.
 the physics involved is a constant .

Flux

  • Super Hero Member Plus
  • *******
  • Posts: 6120
Re: magnets
« Reply #2 on: March 01, 2013, 06:12:03 AM »
Yes it will work for a small fast machine to produce a few watts. To be worthwhile you are really looking at 16 magnets ( 8 on erach disc) for your 6 coils.

Flux

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
Re: magnets
« Reply #3 on: March 01, 2013, 01:47:44 PM »
ok that is my plan 16 magnets in total....and how much thick coil need to be 10mm or more,how much thicknes will rotor have??

Flux

  • Super Hero Member Plus
  • *******
  • Posts: 6120
Re: magnets
« Reply #4 on: March 01, 2013, 02:09:25 PM »
For 3mm thick magnets I would make the coils about 6mm thick and try to keep the gap between magnets under 10mm. The steel for the magnet rotors will most likely be decided by mechanical considerations at a minimum of 3mm thick.


Flux

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
Re: magnets
« Reply #5 on: March 01, 2013, 03:07:46 PM »
ok thanks for help.....

tecker

  • SuperHero Member
  • ******
  • Posts: 2187
Re: magnets
« Reply #6 on: March 02, 2013, 05:31:00 AM »
 With  small builds 8 " and under the coils tend to round out . If you use several strands of say like 21 you can get a compact coil that's able to  switch to get your cut in at whatever speed your blade /rotor can achieve . A single strand of 18 or even 2 strands puts you at at least 300 to 500 rpm really .
 Two rotors of 8" can handle 8 mags at every 45 degrees witch is easy layout  . The size of the coil legs can be related to size of the magnets . I wouldn't make the coils any thicker than the thickness of one magnet .
happy shopping   

electrondady1

  • SuperHero Member
  • ******
  • Posts: 2516
  • Country: ca
Re: magnets
« Reply #7 on: March 02, 2013, 08:11:07 AM »
with 3mm thick mags consider using saw blades as a economic source of steel rotors.

tecker

  • SuperHero Member
  • ******
  • Posts: 2187
Re: magnets
« Reply #8 on: March 03, 2013, 03:02:40 AM »
Yes Plywood blades are good . Also harbor freight has some hand truck wheels with removeable hubs that are roughly two inch square four bolt .

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
Re: magnets
« Reply #9 on: March 03, 2013, 05:45:06 AM »
thanks for help....now what do you suggest for the blades,what size for low wind speed,i live on the hill 140 meters high no obsticals in the aria....

Flux

  • Super Hero Member Plus
  • *******
  • Posts: 6120
Re: magnets
« Reply #10 on: March 03, 2013, 08:19:33 AM »
With those little magnets you are not going to handle more than a few tens of watts. For a low wind area I can't see you handling above a 4 ft prop. At your height with no obstructions, possibly no bigger than 3 ft if you use sensible aerofoil blades. If you use some bent tin things or pvc then iy may take 4ft but you will have to protect in high winds.

Flux

hiker

  • Hero Member
  • *****
  • Posts: 1308
  • BIG DOG
Re: magnets
« Reply #11 on: March 03, 2013, 10:57:02 AM »
WILD in ALASKA

hiker

  • Hero Member
  • *****
  • Posts: 1308
  • BIG DOG
Re: magnets
« Reply #12 on: March 03, 2013, 11:17:57 AM »
heres a short vid--testing out that sawblade alt..150wattts of headlites...
  http://www.youtube.com/watch?v=LSdOwSBXKGg
WILD in ALASKA

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
Re: magnets
« Reply #13 on: March 04, 2013, 10:04:43 AM »
hello...can someone help me how to connect thist in to 3 phase...thanks

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
Re: magnets
« Reply #14 on: March 06, 2013, 02:11:01 PM »
 :(please help...

electrondady1

  • SuperHero Member
  • ******
  • Posts: 2516
  • Country: ca
Re: magnets
« Reply #15 on: March 06, 2013, 04:45:38 PM »
connect 2 and 7

dave ames

  • Full Member
  • ***
  • Posts: 236
  • Country: us
Re: magnets
« Reply #16 on: March 06, 2013, 08:00:14 PM »
For the standard 1-Y, join 2&7, 4&9, 6&11 then join 8,10&12 together (star point)
take the 1,3&5 to the rectifiers.

I would recommend leaving yourself the option of future re-wiring by joining 2&7, 4&9, 6&11 and bringing the other six leads out of the stator. 8)


Edit: Just to add that the above numbering is basied on the diagram by ddaky and the proper numbering system and wiring options can be found on Sparwebs numbering diagram here:
http://www.otherpower.com/images/scimages/4378/Star_Delta_Conxns.gif
« Last Edit: March 06, 2013, 10:39:55 PM by dave ames »

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
Re: magnets
« Reply #17 on: March 07, 2013, 12:09:12 AM »
thanks for help.....

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
Re: magnets
« Reply #18 on: March 08, 2013, 03:16:40 PM »
hello...me again...i need more help...hehe......which diods can i use for this purpose.....thanks... im looking but nothing

dave ames

  • Full Member
  • ***
  • Posts: 236
  • Country: us
Re: magnets
« Reply #19 on: March 11, 2013, 12:19:22 AM »

Were you wanting to kludge something together out of scrap junk used parts to make your own bridge?

I would suggest having a few of these pre=made bridge rectifier blocks at hand for the stuff you are wanting to play with..cheap and easy!

http://www.ebay.com/itm/2pcs-35A-1000V-Metal-Case-Bridge-Rectifier-SEP-KBPC3510-/140804398459?pt=LH_DefaultDomain_0&hash=item20c8989d7b

Cheers, dave

ddaky

  • Newbie
  • *
  • Posts: 20
  • Country: hr
Re: magnets
« Reply #20 on: March 11, 2013, 08:19:09 AM »
hello...i used IN 4007 diode and connected it but nothing i connect one led 3,7v...what can be the problem i connected it like this


dave ames

  • Full Member
  • ***
  • Posts: 236
  • Country: us
Re: magnets
« Reply #21 on: March 12, 2013, 02:41:21 AM »

Hello ddaky,

Hard to guess...what can be the problem. You need to give folks ALOT more information.

Is this some new project? Like some small VCR or hard drive motor you made the bridge for? Or have you managed to get your axial machine together in record time?

If you are using those tiny IN4007'S in anything capable of more than a few hunderd mA I fear they won't last long. <- At least do your best not to short the output or put much of a load on it.....

That brings us to the LED..Any current limiting resistor in series? If you know the open voltage out of your bridge it may be possible to find a resistor value to let 10 or 20mA flow to your LED and let there be light.

Keep up the good fight my friend. And remember the more info the better. For more reading on current limiting resistors for LEDS, go to the site you nicked the rectifier diagram from and see the chapter titled Light-emitting diodes.
http://www.faqs.org/docs/electric/Semi/SEMI_3.html

It's all good fun,
dave