plan-a

Using a pair of ST Micro TDA7498 chips the total admissible output power should in principle reach up to 400 Watts and yet even leave free PCBoard space for additional/optional electronics, if necessary...

Dated (2020-Oct-5).

Evaluated dimensions: 5 x 5 x 1 cm, with 5/8" (dia.) IH Aperture.

Multi-Mode (Universal) IH WorkCoil(s) assembly concept.

Much like the filename says, except for my particular use there can't be any obstruction in the center. See next picture post to gather why...

Solving a tricky 3-D IH problem using ancient Greece knowledge...

That's about the parts count for a "Half-Bridge" power stage feeding some yet-to-define 3-Phase stepper-like IH WorkLoad, properly compensated by using 3 RC "Snubber" circuits (as an EMi-wise addition).

Actually this present post continues a topic initially illustrated 5 years ago, it's about evaluating available space for more eventual IH WorkCoil components but not only: https://www.autoflower.net/forums/media/lavawand-capsule-mating-joint.323/ LavaWand Capsule - Mating Joint (2015-May-14)

It's about straight cylindrical "air-core" selenoïds and their implicit impossibility to "close" the magnetic circuit between 2 ends or poles which in stepper motors are forced to face each other in order to maximize mechanical torque, thanks to flux-concentrating material, etc.