## Easy way to find core saturation point

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• the core begins to take place. The core begins to act as if no iron were present in its core. Because the transformer primary looses its effective impedance,
Message 1 of 4 , Dec 3, 2004

the core begins to take place. The core begins to act
as if no iron were present in its core. Because the
transformer primary looses its effective impedance,
where the presence of iron in the core causes that
impedance effect; beyond that critical voltage input
point, the primary amperage begins to skyrocket, which
if left unchecked will result in insulation meltdown
of the primary. Thus we can burn up a transformer,

Hi!

I will show you very simple method of finding core saturation point. I came on idea during my lab session with transformers and was classified as "nice" in our HAM club (once members figured out how simple it is).

You need:

• some wire (diameter not critical)
• variable voltage source (variac)
• voltmeter

Procedure:

1. Wind some round number of turns in biffilar way on core. Number of turns is best to be around "rule of thumb" formula for calculating transformers (in order to get sufficient impedance while still having amper-turns to saturate core) unless you want to spend too much power and heat wire
2. Connect primary to variac
3. Connect bottom of primary with bottom of secondary
4. Between top of primary and top of secondary place your voltmeter

Start rising voltage slowly. As long as you are not in core saturation, secondary voltage is following primary. Instrument will show small voltage - this represents (roughly) losses into transformer - so called "Kapp triangle".

When you reach saturation point - secondary voltage will not follow primary anymore and difference will rise. Congratulations - you found saturation point!

Now just measure voltage on variac. Divide number of turns with voltage and you immediately get numbers of turns per volt you can maximally apply to selected core in question.

Of course - do not ride till saturation point in practical case; leave some gaps. (unless you want to build scalar wave detector which needs saturation point - with this one you can see if your magnet is strong enough to keep your core in non-linear region)

Those who attempt to "do it yourself" audio output transformers for valve amplifiers will also find this useful - you can without any special equipement (like scopes) find in which part your transformer is most linear and - what is more important - did you sized your airgap in the core (used on DC-biased applications in SE amplifiers) properly or you need adjustements.

If you plot this curve - it will be proportional to first magnetisation curve (so you can see it).

Not very accurate - but extremely useful in practice.

If you want to see hysteresis then you need scope and integrator (since hysteresis curve represent losses as area - it is integral and therefore you need integrator device - prefferably simple one constructed with opamp - see some books for schematics).

You connect primary to AC voltage (mains over variac or sinewawe generator). You connect X of the scope into this. This should be H (magnetomotive force). Then you connect integrator on secondary and output of integrator to Y. This should be B (magnetic flux).

When you callibrate properly - nice hysteresis will appear on screen. You can read:

• core losses (area)
• remanent magnetism (where curve cuts Y axis)
• find saturation point

If using sinewave generator - try to increase frequency and see what will happen.

I am not 100% sure if X and Y should be connected this way (long time passed) - if you get rotated image - simply reverse them.

For VTA group: try to experiment with this setup when it is placed in permanent magnetic field.

I hope you will find this useful.

Jerko.

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• ... Daka. I hope the group will find this useful/ For years I experimented with releasing power of Sf Fe magnet wafers. The ending of that was passing a
Message 2 of 4 , Dec 4, 2004
--- Jerko Golubovic <jerko_golubovic@...> wrote:

>
> the core begins to take place. The core begins to
> act
> as if no iron were present in its core. Because the
> transformer primary looses its effective impedance,
> where the presence of iron in the core causes that
> impedance effect; beyond that critical voltage input
> point, the primary amperage begins to skyrocket,
> which
> if left unchecked will result in insulation meltdown
> of the primary. Thus we can burn up a transformer,
>
> Hi!
>
> I will show you very simple method of finding core
> saturation point. I came on idea during my lab
> session with transformers and was classified as
> "nice" in our HAM club (once members figured out how
> simple it is).
>
> You need:
>
> some wire (diameter not critical)
> variable voltage source (variac)
> voltmeter
>
> Procedure:
>
> Wind some round number of turns in biffilar way
> on core. Number of turns is best to be around "rule
> of thumb" formula for calculating transformers (in
> order to get sufficient impedance while still having
> amper-turns to saturate core) unless you want to
> spend too much power and heat wire
> Connect primary to variac
> Connect bottom of primary with bottom of
> secondary
> Between top of primary and top of secondary place
>
> Start rising voltage slowly. As long as you are not
> in core saturation, secondary voltage is following
> primary. Instrument will show small voltage - this
> represents (roughly) losses into transformer - so
> called "Kapp triangle".
>
> When you reach saturation point - secondary voltage
> will not follow primary anymore and difference will
> rise. Congratulations - you found saturation point!
>
> Now just measure voltage on variac. Divide number of
> turns with voltage and you immediately get numbers
> of turns per volt you can maximally apply to
> selected core in question.
>
> Of course - do not ride till saturation point in
> practical case; leave some gaps. (unless you want to
> build scalar wave detector which needs saturation
> point - with this one you can see if your magnet is
> strong enough to keep your core in non-linear
> region)
>
> Those who attempt to "do it yourself" audio output
> transformers for valve amplifiers will also find
> this useful - you can without any special equipement
> (like scopes) find in which part your transformer is
> most linear and - what is more important - did you
> sized your airgap in the core (used on DC-biased
> applications in SE amplifiers) properly or you need
>
> If you plot this curve - it will be proportional to
> first magnetisation curve (so you can see it).
>
> Not very accurate - but extremely useful in
> practice.
>
> If you want to see hysteresis then you need scope
> and integrator (since hysteresis curve represent
> losses as area - it is integral and therefore you
> need integrator device - prefferably simple one
> constructed with opamp - see some books for
> schematics).
>
> You connect primary to AC voltage (mains over variac
> or sinewawe generator). You connect X of the scope
> into this. This should be H (magnetomotive force).
> Then you connect integrator on secondary and output
> of integrator to Y. This should be B (magnetic
> flux).
>
> When you callibrate properly - nice hysteresis will
> appear on screen. You can read:
>
> core losses (area)
> remanent magnetism (where curve cuts Y axis)
> find saturation point
>
> If using sinewave generator - try to increase
> frequency and see what will happen.
>
> I am not 100% sure if X and Y should be connected
> this way (long time passed) - if you get rotated
> image - simply reverse them.
>
> For VTA group: try to experiment with this setup
> when it is placed in permanent magnetic field.
>
> I hope you will find this useful.
>
> Jerko.
>
Daka. I hope the group will find this useful/
For years I experimented with releasing power of Sf Fe
magnet wafers. The ending of that was passing a
vibration of one magnet to another through space
alone. The ending magnet(S) vibrates and can be felt
by hand. The ending magnet can have an inductor placed
over it, and the inductor registers that vibration,
via scoping of that vibration. It is literally a
magnetic vibration passed through space. The closest
idea of Sweets idea is conveyance of magnetic
vibrations, but I cant make it continuous, when the
source shuts down, so does the vibration. I have never
found a vibration that acts otherwise.

Pray tell me and the audience where such an example
exists! As usually found these things are found by
accidental observations. I was treating a patient via
neon treatment al la Priore method where the ending
body recieves the polar reception of the ending neon
discharge as a polar capacity. I had recomended to him
to place the neon near the actual aluminum foil
connection against his back, which was filled with
boils. The small neon on that connection then began to
give an entirely different glow, a pale discharge vs
the usual orange glow. This was the accidental
introduction of an imperfect electrical connection,
which manifested itself as a small air gap, later to
make a high freq. signal riding on th 60 hz signal
refined to make that a continuous signal to the
patient. This was making a better treatment to the
patient because the arc gap in the series circuit
changed the 60 hz to many high freq signals riding on
that 60 hz.
It is hard for many folks to realize what I am
talking about, so i have supplied some pictures to VTA
list, but perhaps not enough.
Binary Res/ Single Phase/ Neon to Magnet over C(s)
Application.
http://groups.yahoo.com/group/Sweet-VTA/files/ALTMAG/Dsc00411.jpg

What is going on there is a short path to a high
voltage expression of a C value in series with an L
value. L and C are in resonance, from an alternator,
but an alternate pathway is made so that the high
voltage has another pathway directly through the SrFe
magnet wafer, pictured by the yellow wire touching the
top of the magnet , by its own magnetism. Also on the
picture are white an yellow wires that go downward
that lead to aluminum foil connections in which
plexiglass insulation are between those foils, and
that makes the C value for the LC 480 hz resonance. An
alternative (short) pathway is made on the C value's
resonant voltage rise, so that it can light a neon,
then travel through the magnet via the top yellow
wire, and then travel through the remaining plexiglass
top insulator plate via dielectric conduction
currents. Then a coil placed upon the top of this
magnet can scope record the vibrations imposed upon
that ferrite magnet for the simple fact that electric
currents have been passed through the north and south
poles of that magnet. The magnet has been vibrated,
and the coil above that magnet scope records that
vibration. Then one sees a saturation point of the
magnet itself, the magnet will not release more of a
voltage signal to the scope, in accordance to the
voltage imposed upon it by the high voltage neon
exposure of its path, and that signal appears as a
sine wave, not a double sine wave with opposite
signatures. Now we shut the energizing field of the
alternator down, so that practically no action occurs.
The neon does not light, yet the magnet pathway still
exists as a short to the possible resonant voltage
rise. Yet at the same time we see that the scope
signal has now become very active showing much
activity from the magnet...
Parametric Magnet Scoping/ .2 volts@ 2 us/div
http://groups.yahoo.com/group/Sweet-VTA/files/ALTMAG/Dsc00387.jpg

There is a great difference between a "Forced"
vibration, and a free vibration, where the free
vibration itself establishes the same idea as a
saturation point. Something can only be vibrated so
high, and after that no further input of energy can
make it vibrate better. The appearance of double sine
waves has nothing to do with scalar effects either, it
is an idiosynchrosy of recording multiple rf bursts
per source freq on the monitored high frequency. Look
at the thicker white signals/ they are out of phase
with the main ones.ect... In summo I can barely scrape
the bottom of things here, so I scrape-ich.

That exposed magnet in this example vibrates because
it sits on a high voltage electric field, and because
a mechanism has been introduced to pass currents
through its poles. Yet more spectacular examples then
this exist. A magnet such as ferrite can be made to
vibrate through similar examples, and magnets around
it can be made to vibrate; through the medium of space
alone! A magnet can be made to vibrate, and pass its
vibration through space itself. Take my word for that
as it has already been accomplished many years ago.
Guess I'll load a pic to VTA to show that condition
also, where it was found that Priore neon treatment
involving arc gap reflected back to the magnet, in
such a way to cause that magnet to vibrate...
HDN

=====
Tesla Research Group; Pioneering the Applications of Interphasal Resonances http://groups.yahoo.com/group/teslafy/
• Date: Fri, 19 Nov 2004 To: Sweet-VTA@yahoogroups.com ... Hi Mike. Thanx for your very informed comments on transformers. I thought the following would be of
Message 3 of 4 , Dec 4, 2004
Date: Fri, 19 Nov 2004
To: Sweet-VTA@yahoogroups.com

--- Mike <mikefurness2002@...> wrote:

> Perhaps I should add a 'postscript' which was why I
> joined this group.
>
> Common Knowledge, and my training, told me that, as
> even stated in my
> previous note, LINES OF CHANGING FLUX generate
> voltage when cutting
> conductors!
>
> Later we are told that 'in a perfect transformer'
> all the flux is contained
> in the core! So what cuts the wire, certainly NOT
> flux!!!!!
>
> I think the answer to all our endeavours lies in
> this little understood
> 'IGNORED' effect.
>
> Has been called 'MAGNETIC 'A' VECTOR'
>
> Mike.
transformers. I thought the following would be of
interest concerning the A field.
Does the ferromagnetic transformer show the
Aharonov-Bohm effect? (Fri, 27 Feb 2004)

Bill Beauty has a page on the A vector field effect,
which to me now has ceased to be something so exotic
or misunderstandable. Basically the issue seems to be
that a closed loop doesnt need to have a movement of
field lines across its windings for it to contain
induced voltage. The secondary closed loop containing
magnetic flux changing in time can still have an
induced voltage on it by the A field vector.

Heres a reply on the subject to freenrg list.
This E-mail is regarding Bill Beaty's "Right Angle
Circuitry"
http://www.amasci.com/elect/mcoils.html

I find some misconceptions at this site, namely

FIG. 2 A toroidial inductor is interesting because the
induced magnetic field remains hidden within the iron
core. If the coil was wrapped around the entire core
rather than in one spot as shown, then the magnetic
field would exist only within the iron core. In both
cases the magnetic field will exist entirely inside
the core. It is only when the amp-turns of the
windings exceed the transformer ratings, ie
saturation, that the magnetic field lines will start
to emerge in space outside the core. This in turn
will cause the core to act with less impedance, hence
a non linear rise of input amperage vs voltage input
will occur after a certain voltage level is attained.
This can actually happen after a certain point of
voltage input and cause a "runaway amperage " level to
develope, and meltdown of insulation wires may occur.
At full saturation the iron core is entirely
ineffective to produce the impedance to the source,
and the core acts as if it were replaced by air.
Running a 120 volt rated Neon Sign Transformer at 140
volts and beyond will start to cause these saturation
effects, and you will quickly destroy the transformer
insulation on the windings because of the excessive
currents that develope from saturation.

FIG. 3 Even if the coil of wire does not touch the
core, it still induces a strong magnetic field inside
the core. The gap between the coil and the iron ring
can be very large, yet this does not reduce the
strength of the field within the core.[Note; this is
where I have a disagreement, see my concluding
comments on flux density vs cross sectional area
enclosed by loop] The mmf on the
core should be reduced by having a larger volume
inside the exciting windings.

I am not exactly sure about these definitions, but if
the inside volume area of the exciting windings is
doubled, I would venture to say that the mmf on the
core is halved, and vice versa.

FIG. 4 Although the magnetic field stays inside,
something else does come out of the core. The changing
field within the core produces a field of Vector
Potential which surrounds the core. This field is
commonly called the "A-field."

effect which was noted in the late fifties. In 1959
Aharonov and Bohm published a fundamental paper in
Physical Review which pointed out the QM implications
of potentials as the real entities, while force fields
were the real effects. Soon after the publication of
the Aharonov-Bohm effect. experiments showed that, if
the magnetic field is trapped inside a long solenoid ,
a phase shift still is induced in the two slit
electron experiment, even though classically, no
contact of the enclosed magnetic field and the moving
electrons occurs. These are Beardens comments, which I
dont quite exactly understand, which perhaps others
can elaborate on. I do think I understand the premise
in far simpler words. The A field is perpendicular to
the B field. We have two laws to understand the same
phenomenon. The first law is the more familiar one
which states that when a magnetic field line crosses
an orthogonal conductive wire by moving through space
at right angles to that wire, such as occurs when we
rotate a magnet pole at right angle to the wire, a
voltage is induced in that wire that can cause
electron movement in that wire as a consequence of the
magnetic lines of force transversing the wire at right
angles. The second interpretation to me merely
restates the A-B effect WHERE NO MAGNETIC FIELD
CROSSES THE WIRE. Here the induced voltage is
dependent on the enclosed flux (density) change
encompassed on the interior volume area of the loops
containing that flux change. Hence for the
ferromagnetic transformer, the induced voltages and
currents on the secondary already show this AB
principle, since the magnetic field lines are confined
to the core, and do not intersect the secondary
windings, but those windings do recieve emf acording
to delta B/ cross sectional area of flux change.(
which gives the flux density) If we increase that
cross sectional area, ie , increasing the distance of
the transformer windings from the core, this of course
also changes the flux density in the area enclosed by
the loops, since the flux density itself is the amount
of flux divided by the cross sectional area
encompassed by the loops. Less flux density/cross
sectional area of enclosed loops must then translate
to a smaller induced emf. In summo something very
exotic or mysterious is seemingly made that way by
ASSUMING that the transformer example implies a wire
crossing magnetic lines of force, which in actuality
is only a convenient assumption that never actually
occured. Sincerely HDN

> When you wind a secondary, & draw power, the
> secondary flux opposes the
> primary, the flux in the transformer core tries to
> drop, causing reflected
> impedance, & primary current increases to maintain
> the 'status quo', so the
> core flux remains constant. There are many other
> 'peripherial'
> considerations to consider, but minor to main
> diccussion.
If the core flux is dependent on the amp-turns of the
primary input, and the amount of amps on those turns
increases as we draw power, wouldn't the increase of
the mmf by the increased amp-turns also imply an
increased core flux, and not a constant value as you
seem to be implying here?
> When you get to 'serious power' levels, the larger
> core can give a larger
> core factor, so less turns for same inductance, more
> area for cooling, &
> less turns on secondary. From memory only, as my
> work centres on high
> frequency devices, a small 1 - 5 VA transformer may
> have 10 turns per input
> volt, and a large utility one maybe 2 turns per volt
> or less, hence the
> cooling fins you see on them! On 'switchmode'
> devices,
If I understand correctly this would describe the new
solid state neon sign transformers that output some
20,000 hz. I am eager to learn about these devices, so
if you have any corresponding URL's that might
increase my knowledge in this area, they would be
appreciated. Wouldnt we have to use a special ferrite
core for those devices, as silicone iron starts
becoming innefective around 500 hz?

with their
> frequencies of maybe 10 thousand times higher
> frequency, 4 - 20 volts per
> turn is achievable, thus allowing a (UK) 400v
> rectified input, to feed a
> transformer with only 40 turns on the primary & 1
> (one) turn only on the
> secondary for 10 volts out! (Not quite that simple,
> but sufficient for
> example).
>
> I have also done considerable work on 'automotive'
> alternators, They all
> require a 'controllable' field, due to speed & load
> changes, which is
> derived from output windings. Usually a bleed from
> battery to energise, but
> there are some (Motorola, Prestolite) which have a
> small embedded magnetism
> to make them 'self starting'
Seven of Nine Reasons for Gyroscopic Conclusions
jlnlabs@yahoogroups.com- Sat, 22 May 2004
Think of a ferromagnetic metal as a carrier of
uncohered electron spins. If the spins are random in
three dimensions no magnetism is observed. If they are
cohered in that the spins lie predominantly all in one
plane, all in the same direction of spin, then we see
magnetism. Think of these orbiting electron orbits as
molecular gyroscopes. That means when we spin the
metal, a gyroscopic reaction occurs on the
"incorrectly" oriented spins, that tends to "push" the
incorrect spins at an angle that forces a precession
so that these spins all become aligned, exactly as a
collection of randomly oriented gyroscopes on a
spinning disc would behave. Thus macroscopic metallic
spin itself creates a small amount of magnetism, but
not quite the amount of magnetism that would be
released if the metal were made into an electromagnet.
The difference between rotational magnetism and
electromagnetism can be detected with alternator
experiments when we spin the field without it being
energized. A certain amount of rotational saturation
exists, and if the electromagnetism effect has not
surpassed that value, it adds very little to the field
magnetism already present. Following is a past posting
concerning this matter...
Sat Apr 17, 2004 11:22 pm
Subject: Dispelling the Remanent Magnetism of Field
Rotor Theory

Well strictly speaking a ferromagnetic steel probably
does generate magnetism by spin alone, which is even
justified by considering that a gyroscopic reaction to
electron spin orbits would justify this appearance. In
any case the arguments used to say that remanent
magnetism of a alternator field rotor are responsible
for the currents generated by the unenergized field of
a spinning alternator: those arguments would seem to
be like the janitor sweeping the discordant elements
under the rug. Essentially a small unknown phenomenon
doesnt EXACTLY produce ratios of electrical action
comparable to the real operation of the device, and
then we are dealing in potential unknowns, as to how
much electrical power can be obtained by mettallic
spin alone? The electrical power we obtain in that
circumstance might be highly efficient vs the motive
amount of input, and truly here we are bordering on
DePalma ideas himself, which to say the least was
controversial some years ago. In any case using the 3
phase air core principles; and appropriate resonances
attached to the 3 phased inputs I was able to energize
a 20 inch neon tube on one ended disharge which
requires 500-600 volts, and this was made from
ferromagnetic spin of a 480 hz alternator with
unenergized field alone. Here is a sampling of
evidence...

1) Once the diodes from a car alternator are removed,
and a three phase AC conversion of outputs made for
pure form of conversion of its motional spin emf of
the rotor to electrical energy without that DC
conversion, a remarkable increase of output occurs.

2) If we then add resonances as a filter to that
output, and THEN rectify that output interphasingly, I
was able to produce motion on a small 9 volt motor,
which means motion is literally transfered through
wires by spin, with parametric principles. The
ordinary (unergized field)car alternator (with
internal diodes outputing DC) of course should not
accomplish that delivery as its output voltage is
considerably reduced.

3) There is a "correct direction" for inputing DC
current to the field. The wrong direction will result
in less stator output given the amount of field
excitation.

4) Remarkably The actual DC resistance of the field is
affected in a very non-linear manner prior to the
point where electromagnetism of the field rotor
exceeds the pre-existant rotational magnetism.
Initially the field appears as a much higher DC
resistance than is actually measured without motion of
the field rotor taking place.

5) Rotational field "Saturation" is a consequence of
the above observation, where little stator increase
of output from alternator is made until where the
elecrtromagnetic field effects surpass the rotational.

6) DC feedback of parametic stator effects to field to
increase that pre-existant parametric output were once
thought impossible by this researcher, until later
trials many years later showed that in some
circumstances , a delayed reaction occurs, but once it
occurs a magnetic chain reaction occurs in the field,
instantly becoming magnetised to its highest
saturation point, and causing overload on the
alternator, all accomplished through ferromagnetic
spin alone. This Demon of a Beast has never been tamed
by this observer, [Post note; This has now been
controlled via use of a water cell inserted into
alternator resonant circuit to control the voltage on
the field feedback loop] but it should be possible
through
zener diodes. This then could be a self energized
field, made possible by the electrical energy of spin
alone, but controlled in such a manner that the
excessive feedback of that loop does not occur.

7) 7 easy reasons for dispelling the remanent
magnetization of field rotor myth. Once the field is
ACTUALLY energized, and then turned off, we see an
increase of parametric readings. THAT is that totality
of remanent magnetisation effect, which of course is
lost after a certain time after motion of the field
rotor has ceased. It is ONLY that amount of increase
that should be attributed to remanent magnetism of the
field pole faces, and of course the ordinary
parametric levels of operation are then seen when that
remanent magnetism ceases to be present...

HDN

Again another post on this matter;
Several years ago I started working with
the concept of a self energized field for an
alternator. By taking one of the three phases of AC
output, and rectifying it back to DC current for the
field, which is a rotating electromagnet, a runaway
magnetic chain reaction occurs, causing the alternator
to go into overload. This process can start from an
unenergized field, because of remanent magnetization
of the field rotor, because the assembly actually also
acts as a parametric generator,(Delta L on the stator
windings over time acts when the pole faces rotate
inside the stator core, causing a changing inductance
to be recorded on the stator windings, which is the
principle of a parametric oscillator), and thirdly due
to the fact that metallic rotation itself of a
ferromagnetic metal causes a gyroscopic reaction of
the free unpaired electron spins in the electron cloud
of the metal, with the macroscopic result that
metallic spin in of itself also causes a weak magnetic
field to be exhibited. This is also prooved by the
fact that there is a different efficiency of result in
the field's rotating electromagnet dependent on which
polarity we input DC amperage through the field. If
the DC field amperage creates a magnetic field in the
same direction as what the spin itself establishes,
that is the CORRECT polarity to use in establishing
the field, and if it is in the opposite direction, it
must fight the natural tendency of the magnetic field
that itself is estqablished by spin, hence the wrong
direction of DC amperage input means less efficiency
of the alternator per input of the DC fields amperage.
Going even further with DC field studies, it is found
that both BACK emf effects exist; when the fields
amperage creates a magnetic field below that of the
pre-existant magnetic field made by rotation, and even
more importantly FORWARD emf effects can be shown,
where the field starts loosing resistance after
exceeding the rotational pre-existant magnetic field
of the field rotor. This also is easily proovable,
where the DC resistance of my field rotor is 20 ohms
when not moving, some 100 ohms at the lowest levels of
amperage introduction to the field after rotational
movement is established, and finally it becomes around
5 ohms at the point of action I use in experiments.

> You stated that you couldn't exceed 40 volts?
No, what I meant here was that I wouldnt want to
operate past 40 volts for prolonged time periods
because of excessive stator core heating. Actually the
alternator I have used in experiments is a Delco Remy
model that is not a large amperage output model. About
50 or 60 volts output I start hearing significant
bearing knocking noise so I dont press the issue and
operate in sensible power output ranges.
> probably because the unit
> wasn't going fast enough, a 12 volt bobbin probably
> volts, so more core current just causes rapid
> heating.Voltage out (assuming
> constant energisation) is directly proportional to
> speed, rate of change of
> flux,(as in tacho- generator) so much more voltage
> is available if you run
> the device faster.
Yes my pole face field rotor has 7 pole faces, where I
have first tested at 190 hz, and now at a medium rpm
range that outputs 480 hz. Since frequency may also
be an issue with ferromagnetic stator saturation I
wish to keep things below 500 hz, as I have taken out
the diodes to explore the effects of attaching
resonant circuits to the AC output. I have also found
that attached transformers seem to have a non-linear
rise of impedance in accordance with increasing the
frequency input. I would think that operating near 500
hz would be operating near the top limit for
ferromagnetic transformers. These transformers
sometimes also bleed off a lower harmonic into the
sound spectrum producing a whine noise that resembles
a high pitched musical note. Plexiglass plate
capacitors used in 480 hz high voltage resonances
produce this musical note whine at a very high volume.
> As a precursor to designing a high speed
> generating set, I did some
> experimenting with a prestolite 24 volt 175 amp
> truck alternator. The core
> was energised from a seperate 24 volt constant
> supply, rectifiers were
> changed for high voltage 800V PIV devices & unit was
> run into a very large
> water cooled variable resistance nerwork.
> The speed at which the rotor started to 'grow' was
> at 24,000 RPM, off load
> voltage was about 310 volts,(declining rapidly with
> continuous power out, 26KW
Hmm, I am jealous now, I need to set up a alternator
that has more guts and power, your work sounds
interesting.
> An interesting discovery was that (as per
> transformer) when the 'ampere
> turns' in the stator equalled the ampere turns in
> the core, (at 175 amps)
> the unit would give no more, even into a short
> unloaded the prime mover & didn't overheat. maximum
> power out was obtained
This sounds somewhat interesting because when I
arranged things according to the principle of maximum
energy transfer and resonated those resistances made
into the form of a spiral, I was also able to output
larger amperages without any significant stator
heating occuring. It is only when I put interphasal
loads on the resonance's voltage rises that
significant stator heating then is observed. I called
the spirals METR components, {Maximum Energy Transfer
Resonances}. What seems to go beyond the established
electrical theory is that they obey the aspect that
the voltage drop in comparison to open circuit voltage
will be about 50%, but acoording to theory there is
also supposed to be a corresponding 50% drop of
amperage compared to the value obtained when shorting
out the outputs. Instead these resonances obtain the
same value of amperage that will be found when the
outputs are instead shorted. The METR components were
by noting what voltage appeared across the outputs
when shorted, and the dividing the obtained amperage
by the obtained voltage, giving a value near a half
ohm for this particular Delco Remy alternator.
Everything had to be duplicated for all three phases,
or else different values for R(int) were obtained. A
short on two phases produces more current on the
phases then for the case when all three phases were
shorted.
> It was decided that this arrangement would not be
> ideal, so I called in
> outside help to design a 90,000RPM direct drive
> alternator (genset to be
> powered initially with Russian cruise missile
> engine, 50KW at 90,000RPM)
> Permanent magnet, no brushes at that speed, Output
> voltage 210 off load & 90
> volts full load, boost transistor to take this to
> the 800v required for PWM
> line invertor.
Whew how in the hell can bearings stand such an
excessive rpm! I also have a set of paired bus
alternators that I think are known as reluctance
alternators. Those alternators have a cup shaped field
that does not revolve! Instead a tight clearance is
involved where a set of rotating pole faces rotate
around this metallic cup. The pole faces "grab" the
fields magnetism by being a path of least reluctance.
Since the field itself does not rotate, there are no
brushes or slip rings in that model.
> Whole device intended to weigh 40KG (90 pounds) &
> highly portable. Still
> have some very large transistors laying around.
Each of the bus alternators also probably weigh at
least 90 lbs also. They even have inputs for oil
cooling like a transmission! These are some monster
machines that need a 240 volt AC motor to turn the
pair which outputs 360 hz.! The stator windings are
made from varnished thick copper bus bar type windings
intersecting segments of laminated silicone iron. The
pole faces rotate just underneath this assembly. Only
59 stator winds are around the circle, making for 18
winds per phase. I have not turned this machine on for
several years, as the smaller alternator provides for
a convenient tool for researching effects of
resonance, and also I dont have 240 VAC in the garage
and must use a long extension cord taken from the air
conditioning 240 outlet. Since these alternators are
paired by a variable connection pulley, this gives the
option of making a special 6 phase system, where any
desired phase angle between the two 3 phase systems
can be procured. Spent a lot of money on that project!
The AC phases are also isolated, meaning that they can
be outputed in either delta or wye, or in perfect
isolation.
> Sorry to have wandered so far 'off topic' thought
> it might have some
> general interest.
Enjoyed the interchange of information... Thanks, it
wasnt off topic for me...HDN
> Mike.
>
> Mike. J. Furness.
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