|
I thought Al values was a meaningless term for pure
ferrite materials and is only published as a guideline as it changes
dramatically with temperature and B - for a true/ideal transformer it would
ideally be infinite. Things like bulk resistivity and the area
inside the hysteresis curve are more significant as they decide the frequency
and power handling of any material.
Andy G4JNT
----- Original Message -----
Sent: Sunday, January 11, 2004 9:07
AM
Subject: LF: 3C90 Al value?
Hello Group.
After a 4 month wait I've
received a batch of 58mm cores claiming to be 3C90, but according to the
catalogue they have the wrong colour code. These are white (pos 3C11) not
blue/white for 3C90.
The way to confirm is to calculate the Al value
and compare to the data on 3C90 3C85 3C11 etc materials. Unfortunately 3C90 is
not listed in my old data book.
I've measured the inductance of a 21
turn winding at 1.43mH.
Using L = Al x N squared, this suggests an
Al value of 3249.
Is this a good figure for 3C90? It does seem
far too low for 3C11 (5000+)
Perhaps they've changed the colour code
again?
73
David
G0MRF
| 