Tony Williams wrote:

It's an inverter plus tuned tank coil generating a high
frequency magnetic field that induces eddy current and
hysteresis losses in the iron pot/pan, which then gets
hot. Note the need for iron, not aluminium.

The advantage is that the heat is concentrated only in
the iron pot/pan, the rest of the stove stays cool.

Thanks for that. I was familiar with the principle, but not the
frequency of operation. Most web site descriptions seem to be at the
"magic force field" level of explanation! Some sort-of imply mains
frequency operation, but I could never quite see that working with such
a large air gap in the magnetic circuit.

So by "high frequency" you mean what - the low kHz range, perhaps?

--
Andy