Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> Hi Mike,Normally if the primary is too high in frequency compared to the secondary and the primary is already too large, people add more Cp to bring it down to where the secondary is. If your secondary has a small toroid compared to the size of the secondary, it sounds like you have already tried to "up" the frequency to match the primary. To me, this sounds like your secondary is way too large for your power source, but at least you have room to grow. When you do get more power, you can add more Cp and go with a more reasonable size toroid for your secondary size. BTW, what is your power source???
Gerry R
Original poster: "Mike Tucknott" <michael.tucknott@xxxxxxxxxx> I`m not sure how close I need to be to get the coil to work. I need 0.281mH of inductance from the primary to run with a frequency of 67.09 KHz, that's why the top load is small compared to the overall coil size. I`v got 0.261mH of primary inductance to start with I`m just going to run the thing and see. If I went with a bigger top load the frequency comes down and I need more primary inductance.