# Current Output for ZVS Flyback Transformer

What is the typical current output for high voltage of ZVS flyback transformer or how to properly measure it?

Update with the schematic, the fly-back transformer is typical one used in old CRT TV;

• Somewhere betweeen 1 uA and 100 amps. Show a schematic if you want a better answer. – Andy aka Jun 2 '17 at 9:57

Measure the diameter of the secondary winding (d), then calculate its cross sectional area via $A = \pi \ d^2/4$. If secondary winding consists of paralleled multiple windings then you need to calculate total cross sectional area.
Maximum allowed continuous current can be approximated from $I_M = J \cdot A$, where $J$ is the current density with an assumption of $J=420\ Amperes/cm^2$. (Actually this $J$ value is valid for almost all SMPS power transformers as well).