|
|
|
| Re: (Wind Nerd alert) Mini Axial Flux Alternator Parts [message #24050 is a reply to message #24002 ] Sat, 19 February 2011 07:15 UTC |
  |
|
Very neat!
It would be interesting to see what power you get out of that little alt, and more interestingly how fast you need to make it spin (I'm guesstimating upwards of 400 rpm just to get enough volts to see DC after the rectifier)
A few of my observations, and questions.
Does it have a ferrous plate behind the magnets to maximixe the magnetic flux density? Are there two magnet rotors to concentrate the flux through the coil legs?
8 coils and 6 magnets is an unorthodox layout, how does the phasing work out? Usual configurations are 10 or 5 coils with 12 or 6 magnets for 5 phase, 9 coils with 12 magnets for 3 phase, 12 or 6 magnets 6 or 3 coils for single phase.
If you need any help planning the layout for your alternators, feel free to ask... small size alternators happen to be something I'm very keen on, as you can see from my LEGO weight driven generator
@Dizingof... reverse engineering a 'Shaker Light' would help you out - but there's not much power to be had.
p.s. have a search for MOSFET rectifier for the least voltage drop in converting to DC. Geranium diodes also have a very low voltage drop, but they do not have very good reverse voltage tolerance.
[Updated on: Sat, 19 February 2011 07:38 UTC]
|
|
|
| Re: (Wind Nerd alert) Mini Axial Flux Alternator Parts [message #24085 is a reply to message #24002 ] Sun, 20 February 2011 23:17 UTC |
|
|
Hi Dizingof, yes I went for more turns in order to get the voltage up, in order to get past the diodes, and power loss increases with current.
I didnt play with flux density yet - this wasnt about maximising power yet. It would be interesting to run it in alumide and let the induced current alter flux density. Perhaps.
Yes it's an odd ratio of coils to magnets - it was an idea I had to gang each opposite set of coils together to get four coil phases being jumped in turn by 6 magnets. I havent hooked it up yet beyond a single coil, it made sense after a few beers but i think I will need to sit down with paper and some diodes and rethink it. Otherwise I will develop a new 3d model with the traditional recipe of ~1.34 magnets per coil. A quick open circuit test only went with millivolts. In hindsight I should have gone for 0.4mm wire or less.
What I really wanted out of this was something people could buy, pop together and built their confidence, before scaling it up into something at least 10 times bigger. I'm not keen to get anything other than milliwatts out of it. Great idea on germanium diodes - I'll be checking that out. I'll post more soon...
[Updated on: Sun, 20 February 2011 23:20 UTC]
|
|
|
|
| Re: (Wind Nerd alert) Mini Axial Flux Alternator Parts [message #24120 is a reply to message #24106 ] Mon, 21 February 2011 21:56 UTC |
|
|
|
Well I did think of calling it the flux capacitor, but I doubt I'll get 'one point twentyone gigawatts' from it as the Doc says on back to the future. Perhaps we could model a small delorean to mount it on....
[Updated on: Mon, 21 February 2011 21:57 UTC]
|
|
|
| Re: (Wind Nerd alert) Mini Axial Flux Alternator Parts [message #24166 is a reply to message #24120 ] Wed, 23 February 2011 17:29 UTC |
|
|
Did you get any numbers out of that alt yet?
I've had an idea for a stator planned out for a while, its based on Ed Lenz's 'Slotty Thing' alternator 'coil' former (dunno if you've seen his stuff - http://www.windstuffnow.com ), he used to post over on http://www.fieldlines.com too... anyways alts aren't a new idea, but combining 3D printing and alt manufacture are. Are you ok with me having a hit at designing an alt? (asking first so as not to tread on toes)
[Updated on: Wed, 23 February 2011 17:30 UTC]
|
|
|
|
| Re: (Wind Nerd alert) Mini Axial Flux Alternator Parts [message #24185 is a reply to message #24172 ] Thu, 24 February 2011 07:37 UTC |
|
|
Upon seeing your alt, one of the first things I did was to replicate the layout in Corel Draw... you could series opposite coils for a four phase alt, I think the phases would be out enough that you'd need to rectify each phase individually.
If I got your dimensions right, you may have enough spare room on the rotor to go to 8 magnets and series all the coils for a single phase unit. Without any kind of flux channeling (steel backing for the magnets, dual rotor etc), I'd guesstimate you'd need about 1200-1600 turns total (150-200 turns per coil) and have the rotor spinning at 300+rpm to make 4v after the rectifier.
I see you have a hole in the stator casing below each bobbin... could the wire from the bobbin be fed out through this hole? If so, you would be able to get the magnets a little closer to the coils which would help things a bit.
I'd be happy to colaborate in a design 
|
|
|
Search
Re: (Wind Nerd alert) Mini Axial Flux Alternator Parts
