zvs full ridge converter

My Webpagehai every one,,,,

i want to build a 1kw float charger ..... i deside to use zvs variable frequency control full bridge converter to convert 230 V AC to 48 V DC.i reffered some application notes regarding the full bridge transformer design and the resonant tank circuit (i want to know how to choose the resonant frequency for the resonant tank circuit and the tank elements L & C) but still i am not sure about it........
Please give me your valuable suggestions for the transformer and resonant tank element design,if you give me design example i will be very much thankful to you,,.
Please let me know,,,,,,,

Thanks & Regards

Kamal