Questions about size of magnetic wire to use

[[email protected]]

I'm not actually talking about wind. They have 100hp AC induction
motors for $200 on ebay (probably plus a ton of shipping) and they are
seriously nowhere near the size your talking about. Probably 1/4 the
size of a car and they put out a ton more than I need. I see people
all the time getting ~ 1kw or so with smaller designs. For instance
the site I linked to they have a larger 12" version that can get 700
watts or so at under 600RPM. I'm looking at closer to 1500RPM.

You might easily build an alternator that size, but the means to drive
it with wind power? I seriously doubt that a 12" wheel is going to
catch enough wind. 700 watts is over one horsepower. Even a 1/3 hp
fan is a pretty big deal, for the motor and size of the blades to use
that much energy.

Ok here's a few induction motors 1 hp single phase - 42 pounds
1 hp single phase 32 pounds, 3/4 horse, 25 pounds, all about 9.9"
X6.5"

The 600 watt wind power generator with the 6.5 foot blades and 14 AWG
wire and two sets of real magnets is believable. 800 watts peak

Now if you're talking about the double rotor one with the 6.5 foot
blades - I believe that can make some power. And its a far cry from
the demonstrator you're talking about and still one sixth to one tenth
of the size you'd need for 5 killowatts. And he's talking about
serious wind to power it to that level.

I live on the coast and see winds of >30 mph maybe 20 days a year.

 

[Jasen Betts]

I'm not using completely stock parts. For instance I'm using two
bridge rectifiers instead of the diodes. Yes I'm looking at scaling it
to 12-20 inches, triple the magnets (5 times the strength each) and
triple the coils. The configuration I mentioned was not to get more
power off of it. Its to divide the amps out so the thing does not
overheat and I could use smaller wire. A huge amount of coils
producing 1.5Amps each would be easier to manage than the entire device
putting out 54 or so combined off of 3 20 guage wires. Or I could just
divide it into quadrants and split it out among 12? That would be
easier to manage.

why do you want to use thin wire?

you can use thin wire in a design that calls for thick wire by just bunching
a number of thin wires together wan winding them in the place of the thick
wire.

 

[[email protected]]

I'm not using completely stock parts. For instance I'm using two

why do you want to use thin wire?

you can use thin wire in a design that calls for thick wire by just bunching
a number of thin wires together wan winding them in the place of the thick
wire.

AWG20 doesn't really feel thin to me Less RPM, more turns, easier to
work with. Cheaper per foot, etc.

 

[[email protected]]

Still not wind power I'll spin it at 6000 RPM if thats what it
takes but prefer 2500 or less. I guess its best to move up to 20 inch.
I'll probably do 3 sets of 18 coils on a three 3-phase bridge
rectifiers and possilby bump up to AWG18.

Eirc

 

[[email protected]]

Still less than ideal circumstances and I've pulled over 7w out of that
3.5" rotor. Highest I've seen is 11.4v @ .65amps Less than 1000
rpm still. That was delta configuration. Configured as star I saw
about 15v at 0.3 amps.

 

[[email protected]]

Still less than ideal circumstances and I've pulled over 7w out of that
3.5" rotor. Highest I've seen is 11.4v @ .65amps Less than 1000
rpm still. That was delta configuration. Configured as star I saw
about 15v at 0.3 amps.

By less than ideal I mean I've not found the hardware I'm looking for
yet. What I'm spinning it with is held on by tape and it slips at
higher RPM. Also I tried putting a small nail under each coil but it
introduced a lot of drag. Maybe if it were a little further from the
magnet.

Eric

 

[Jasen Betts]

AWG20 doesn't really feel thin to me Less RPM, more turns, easier to
work with. Cheaper per foot, etc.

cheaper per foot but you need more feet - really it depends how many volts
you want. it seemed to me that you talked about putting windings in parallel

A huge amount of coils producing 1.5Amps each would be easier to manage
than the entire device putting out 54 or so combined off of 3 20 guage
wires.

I think it's better to put the windings in series
I wouldn't want to see 54amps in a 20 gague wire,
I think even a 15A fuse wire is thicker than that.

if performance at low RPM is an issue go with 18 poles on the rotor
(alternate N,S,N,S) and altenate your three phases round the stator

hook the windings of each phase in series and use a three phase bridge
rectifier (or 6 diodes, or 1-1/2 regular AC bridge rectifiers)

Automotive altenators use a similar design for similar reasons.

Bye.
Jasen

 

[[email protected]]

A huge amount of coils producing 1.5Amps each would be easier to manage

I think it's better to put the windings in series
I wouldn't want to see 54amps in a 20 gague wire,
I think even a 15A fuse wire is thicker than that.

if performance at low RPM is an issue go with 18 poles on the rotor
(alternate N,S,N,S) and altenate your three phases round the stator

hook the windings of each phase in series and use a three phase bridge
rectifier (or 6 diodes, or 1-1/2 regular AC bridge rectifiers)

Automotive altenators use a similar design for similar reasons.

Bye.
Jasen

I think you missed the point. There shouldn't be 54 amps going through
the 20 guage wire. If I divided it in 6 sections for instance it would
likely be 9amps, or 1amp if I had 54 3-phase bridge rectifiers. From
the bridge rectifiers +/- I can use large cable.

Eric

 

[[email protected]]

Thanks to everyone that helped. I've been reading a little more on
that site. I guess I mistakenly thought I'd need hundreds of turns per
coil to get over 12v off of the thing. I'm looking at doing something
similar to the dual 8" rotor design (with original 36 slot stator) now.
With wind generated speeds he has gotten 815W (albeit 32mph) off that
sucker and only used 20 turns of 14AWG wire. I might try the exact
setup with 25 turns of 10AWG wire and a lot more powerful magnets.
I've ordered an extra 6 magnets so I can do it (it needs 24).

Eric

 

[JosephKK]

reply interstitial

One do wonder what calculations he's referring to; that would
probably be interesting reading.

I've only seen pictures of them.
How was the fidelity? and what ips was the wire traveling at? Was
the wire malleable or stiff?

In the early 60's i had the "pleasure" of tinkering with a working unit,
They were actually from the 30's or 40's, i could tell from the tube types
(even though is was a kid at the time, i also had transistors and early
op-amps to play with at the same time)

I came across and antique store around here that has a stock of old
original Model T coils.

I built my induction coil to work as a transformer on 120 VAC and
spark coil on 50 VDC. It was used to excite the Tesla coils I was
working on. As a transformer I could only get ~6-7 KV out and as and
induction coil ~100KV.

I wound one primary on 12 gauge steel wire (stuff used to hang
ceilings with - straight 8' pieces in bundles - cut to 18") and a
second primary with 20 gauge electric fence wire. Almost no
performance difference with the two wire sizes (primary turns the same
, secondary turns the same) Primary is 354 Turns X four layers - can
be switched into parallel and series arrangements. Secondary is
~67,800 turns (resistance came out to within 300 feet of the design
value).

Using steel wire for conductors is suboptimal and uncommon. I built some
tesla coils myself along the way, had one good one, about 7-1/2 inch
airspike and lit fluorescent tubes for about 20 feet. Estimated secondary
voltage about 750 kV.

 

[JosephKK]

AWG20 doesn't really feel thin to me Less RPM, more turns, easier to
work with. Cheaper per foot, etc.

Whoa, 20 gauge not thin? I have worked with 500MCM all the way down to 46
gauge. Overall, 20 Ga is thin. Just the same, i still do not understand
what you are trying to do. Are you building a generator, a motor or what?

 

[JosephKK]

I'm not actually talking about wind. They have 100hp AC induction
motors for $200 on ebay (probably plus a ton of shipping) and they are
seriously nowhere near the size your talking about. Probably 1/4 the
size of a car and they put out a ton more than I need. I see people
all the time getting ~ 1kw or so with smaller designs. For instance
the site I linked to they have a larger 12" version that can get 700
watts or so at under 600RPM. I'm looking at closer to 1500RPM.

Eric

So it seem we are talking about generators. rpm per se does not have to be
an issue.

 

[JosephKK]

if it's a wind turbine it's unlikely to produce usable AC.
convert it to DC and use an inverter

Bye.
Jasen

Jasen, how about you research induction generators for producing AC power.

 

[default]

reply interstitial

= "in between"

In the early 60's i had the "pleasure" of tinkering with a working unit,
They were actually from the 30's or 40's, i could tell from the tube types
(even though is was a kid at the time, i also had transistors and early
op-amps to play with at the same time)

Using steel wire for conductors is suboptimal and uncommon. I built some
tesla coils myself along the way, had one good one, about 7-1/2 inch
airspike and lit fluorescent tubes for about 20 feet. Estimated secondary
voltage about 750 kV.

I wound the primary of the induction coil ON a core of bundled steel
wires. I tried both 12 gauge wire and 20 gauge for the core. The
primary winding was/is 16 AWG enameled copper in both cases.

My 300 watt Tesla coil (oil burner ignition for primary spark) would
work in the range you mention. The 1KW excitation would send the
spark to dangerous lengths - hit my stereo speakers, wiped out the ram
in the computer, would hit the walls - wood and wall board seemed to
be conductive at whatever voltage it developed.

I noticed three distinct types of secondary sparks depending on the
secondary coil and excitation. I built ~10 secondary coils and 4
primaries. Long streamers with a blue flame type of discharge that
would rotate slowly around the end ball I figured for low voltage and
high power, long white noisy sparks with high voltage and high power
(with a large top terminal capacitance), and smaller forked lightening
type of discharge (lots of branches in the spark tree) with high
voltage and low power.

Best secondary was with silver plated wire wrap wire and coated with
epoxy on a 4" PVC pipe form. Best primaries were a spiral of aluminum
wire and a helix of 12 AWG copper with spaced turns supported by
varnished wood slats.

Tesla coils are great fun. One does get an understanding of things
like insulations - dielectric strength and dissipation factor,
standing waves, resonance, skin effect, etc..

I could make X-rays and ozone.

Did you build your own capacitors? I did for the most part -
commercial ones that I could afford just didn't last long. I had some
hockey puck sized transmitting caps that worked well, but most of my
caps were 1/8" window glass with aluminum flashing for the plates
(potted in wax filled wood boxes)

I too started early. I started tinkering in grade school with vacuum
tubes and the few transistors I could get my hands on.