In this video, we demonstrate using a Mazilli or Royer oscillator driver with 100 nF resonant capaicutor and using IRFP260N and MOSFETS to drive a gapped ferrite core at a resonant frequency of 218 kHz. At this high frequency we can heat small metal objects very quickly. This will allow braising of small metal parts. This is especially useful in jewelry and in annealing brass cartridges from spent ammunition. Typically, approximately 60V DC from a SMPS will work great, but also AC from a variac can be used. The video here demonstrates the heating effect of the high permeability ferrite toroid with a small gap cut in the ferrite to reduce ferrite heating and cracking.
There is a tradeoff between permeability of the gapped ferrite and heating of the ferrite versus heating of the workpiece.
If you enjoy this video, please check back often because I’m about to put up a test experiment in the next couple of weeks attempting to make a battery powered instant hot water heater. look forward to seeing you back soon. 
The gates of the MOSFETs are powered separately with 12 V wall adapter.
Schematic:
https://drive.google.com/file/d/1U3Cp...
Latest Gerber:
https://drive.google.com/file/d/1vwFN...
BOM:
https://docs.google.com/spreadsheets/...
Watch video Ferrite Gap Spot Heater Demo online without registration, duration hours minute second in high quality. This video was added by user SciTubeHD 19 October 2024, don't forget to share it with your friends and acquaintances, it has been viewed on our site 14,063 once and liked it 528 people.