belax
Member level 2
transformer 60khz
Have a question about transformer calculation for half-bridge topology.
Want to say that I am not experienced in transformer calculation.
I need to design a transformer which should feed the purely resistive load with 850VAC, 60khz. The power of the transformer should be 55W. I have chosen a core EFD30/15/9 with ferrite N87.
I am using the half-bridge topology. One end of the primary winding is connected to the middle point of capacitor divider (150V) and another end is connected alternatively to the ground or 300V by means of two MOSFET switches. The secondary winding is connected to the load which can be any from the range of 11 kOhm to 100 kOhm. I am using IR2153 driver.
I started the calculation with determining the primary(w1) and secondary (w2) turns number.
Used this formula:
w1 = U1/(4*q*Bm*S*f), where U1 = 150V, Bm = 0.12T, S = 69mm^2, f = 60khz, q = T/(2*t), where T = 1/f, and t is a pulse length (I use ir2153 it has 0.6 usec dead-time)
So I got w1 = 57 turns.
Then I calculated w2 ~ 280 turns (used the same formula).
But I don’t know what to do next - how to determine the air-gap.
Please, can anybody tell me how to calculate the air-gap for the transformer in order it could work without over-heating? Also would like to hear any advices about the calculation of such transformers?
Thank you very much.
Have a question about transformer calculation for half-bridge topology.
Want to say that I am not experienced in transformer calculation.
I need to design a transformer which should feed the purely resistive load with 850VAC, 60khz. The power of the transformer should be 55W. I have chosen a core EFD30/15/9 with ferrite N87.
I am using the half-bridge topology. One end of the primary winding is connected to the middle point of capacitor divider (150V) and another end is connected alternatively to the ground or 300V by means of two MOSFET switches. The secondary winding is connected to the load which can be any from the range of 11 kOhm to 100 kOhm. I am using IR2153 driver.
I started the calculation with determining the primary(w1) and secondary (w2) turns number.
Used this formula:
w1 = U1/(4*q*Bm*S*f), where U1 = 150V, Bm = 0.12T, S = 69mm^2, f = 60khz, q = T/(2*t), where T = 1/f, and t is a pulse length (I use ir2153 it has 0.6 usec dead-time)
So I got w1 = 57 turns.
Then I calculated w2 ~ 280 turns (used the same formula).
But I don’t know what to do next - how to determine the air-gap.
Please, can anybody tell me how to calculate the air-gap for the transformer in order it could work without over-heating? Also would like to hear any advices about the calculation of such transformers?
Thank you very much.