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Hi:

Please see this simple induction coil driver circuit (made public): https://www.circuitlab.com/editor/3x4ckhd5xcd4/

If CLK1 is set to exactly 10.000000 kHz, the simulation plots are rubbish.

If CLK1 is set to either 9.99999 kHz or 10.00001 kHz, it produces the expected plots. The number of decimal places doesn't much matter as long as the frequency isn't exactly 10.000000000 kHz. This occurs at some other values of frequency that are round numbers. For example, if L2 is changed to 2.5 uH then the same thing occurs at 40 kHz. And slightly changing the values for L1, L2, C2, C3 doesn't make much difference.

There is nothing in the circuit that should be so frequency dependent.

Thanks,

--- sam