Phil Allison wrote:
"Patrick Turner" = asinine, criminal ****wit
Phil Allison
It is most likely you have good GOSS material in the test core you used in
your
test.
** It is a certainty since that is the only material used.
And I maintain that just because some GOSS is wound into a spiral,
the U compared to an interleaved E&I tranny won't necessarily be
10 to 15 times what it is in the E&I lams.
** Two counter examples:
#1.
The I mag @ 240 volts for a 300 VA mains toroidal ( from Harbuch) on the
bench is 11mA rms.
At 120 volts, I mag falls to 1.7 mA, becomes sine wave and has a 12 degree
phase angle.
The load R is effectively 70 kohms.
For this case, L computes to be over 1000 H using: L = R / ( 2.pi.50.
tan 12d )
#2.
The I mag @ 240 volts for a 160 VA mains toroidal ( from Jaycar) on the
bench is 7 mA rms.
At 120 volts, the I mag falls to 1.6 mA, becomes near sine wave and has a 15
degree phase angle.
The load R is effectively 75 kohms.
L computes to be nearly 900 H.
You are quite right with all these calcs
I get quite high enough inductance figures with the GOSS E&I material
I use from Sankey.
For an iron cored inductor, with no unbalanced DC flow in only one direction, as
in an SE amp,
or with balanced DC, as in the case of a PP amp, or a mains tranny is
1.26 x Np squared x Afe x U
Lp = ---------------------------------
1,000,000,000 x ML
Where Lp = primary inductance in Henrys,
1.26 is a constant,
Np = primary turns,
Afe is the cross sectional area of the core in square mm,
U is the mu of the iron at low voltage levels,
1,000,000,000 is a constant,
ML is the magnetic path length around the core in mm.
Now its obvious from your measurements that the
L was more at 120v than 240v input, which tells
you the U of the material has declined with increasing voltage, ie
increasing Bmax.
You know all the items in the above formula except U.
What is the U for the 240v and 120v conditions?
If the current at 240v is badly distorted, the calculation of L at
the higher Vin is questionable.
But max U may be well below saturation onset, and maybe at
180v input.
So what maximum U are you getting?
I try to run my trannies at about 0.85T, and U is at its highest, losses are
negligible, and even with crummy NOSS E&I cores the outcome is acceptable
because the item is quiet and cool.
The para quoted below does not even contain the word "toroidal " so has
no
relevance to the heading - as is usual for the Turneroid autistic .
But it was from Tortech, who praise the virtues of their toroidal wares...
** More autistic Turneroid excrement - what a ****ing pong !!!
I didn't think a pong could copulate, but anything is possible in your
imagination.
Patrick Turner.
.............. Phil
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