Explain please

This is how an LC circuit operates. L meaning inductor. So you charge the capacitors, then they discharge their charge through the inductor, in this case it is the primary of the transformer. The inductor stores this charge in its magnetic field, as its field starts to collapse it induces a current back into the capacitors and they charge up. Then the cycle repeats. It will eventually stop though, as power is lost through being transmitted each time, and through the magnetic field of the inductor. If you watch the max value on the scope starts to decrease. On a different note, the transformer you have here serves no purpose, other than just discussed. It will not light the led on the other side because transformers only pass ac current, you have it hooked up to a dc power supply.

Yes, but why if I hold button pressed for a while, led start to light in DC current?

Because the sim sees it as the magnetic field is increasing, and makes current flow on the other side of the transformer. However in real life, you need ac to make a transformer work because you need the current to alternate so it creates a fluctuating magnetic field to induce the current. It's just a glitch in the sim. Try it in real life, there's a reason we don't use dc for transformers.

transformer in EC has 100mΩ resistance. capacitor in EC has 0Ω resistance. switch in EC has 0Ω resistance

On primary its constant 100mOhm. On secondary it depends on transformation ratio. In this case 1:200 its 200*0.1 Ohm=20 Ohm. And the inductivity is 400000H cuz its square ratio multiplied with primary inductivity 10H. 10*200^2!

Thanks to all

The capacitors and the inductance of the transformer generates a resonance

Thanks 100 makes sense