22 February 2020
- Last edited 22 February 2020
Alright, let's deep dive! We are interested in square wave with a duty of about 10%. I'll do the calculations for Hitachi AMCC-200.
We have a formula to calculate the number of turns in the primary coil:
Npri = Vin * 10^8 / 4 * f * Bmax * Ac
The main concern is not to saturate the core. This happens if the magnetic field density generated by the work of the transformer exceeds the maximum density supported by the core, Bmax.
Let's see what is Bmax for Hitachi AMCC 200 according to the datasheet.
A Bmax value of 1 T = 10000 Gauss should be well within the safe interval.
Please keep in mind this applies to a transformer, so It's about the flux moving during the on-time. I'll analyze what happens during the off-time also.
I fixed the datasheet link to point to the right alloy and I fixed the Bmax value. I'm also thinking about making a calculation for the suitcase device we saw from Don Smith. Stay tuned.