Excellent!
You did a good job here. In fact, way better than i did when I was at your age. Hope your success inspires you to the next project. Keep 'er up!
I did a similar ESR meter based on the same schematic, a couple of years ago. But, I simplified it a bit (in my opinion) by using a LM311 as a signal source and then fed the signal to a little transformer (I rewound it) robbed from a CFL power supply.
Don't worry too much about your english.
