I am using PCB mount transformer which is having 1:100 turn ratio.
This transformer is using for converting 5V to 500VDC.
In my circuit it consuming 150mA@5V is it OK?
i am switching the transformer at 25KHz.
How to estimate the switching frequency of my transformer.
Use the equation for square waves: Primary peak Voltage * 0.5 / frequency = Number of turns * Cross section area of core * Maximum flux density
For ferrite cores take maximum flux density as 0.2
'Switching' does not give enough info. A power transformer is tight coupled power transfer which is not required to store energy in core, just tightly couple it to secondary. A flyback transformer is really a coupled inductor. A flyback transformer core stores energy and returns it to secondary winding.
The two use different core designs. Power transformers are not usually gapped where flyback transformer often are to increase energy storage capability.