Hi all,
I have an experiment im working on and i need to know the typical inductance of a computer smps primary coil [the biggest transformer in the device]. Im driving it with 50Khz to 70Khz squarewave signal.
Ive tried the age-old inductance formula for cylindrical inductors for a coil i wound on the smps core with 19SWG wire(1.006mm), 3cm long 1cm diameter and one layer thick. I ask this because on spice, it shows outrageous voltages and current at the low-side mosfet switch [i know that this usually happens within a small timespan].
For the record, i'll use this just as a pointer for my project to see if i'm going nuts with inductance calculations.
Three questions...
1. Anyone have an idea or measured value?
2. Does one use the value 720 or 150 for iron core for the relative permeability of the core?
3. Does one have to match the inductances of the primary coil and the secondary coils in any transformer?
thanks in advance.
I have an experiment im working on and i need to know the typical inductance of a computer smps primary coil [the biggest transformer in the device]. Im driving it with 50Khz to 70Khz squarewave signal.
Ive tried the age-old inductance formula for cylindrical inductors for a coil i wound on the smps core with 19SWG wire(1.006mm), 3cm long 1cm diameter and one layer thick. I ask this because on spice, it shows outrageous voltages and current at the low-side mosfet switch [i know that this usually happens within a small timespan].
For the record, i'll use this just as a pointer for my project to see if i'm going nuts with inductance calculations.
Three questions...
1. Anyone have an idea or measured value?
2. Does one use the value 720 or 150 for iron core for the relative permeability of the core?
3. Does one have to match the inductances of the primary coil and the secondary coils in any transformer?
thanks in advance.
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