DIY Induction Heater
- Uncontrolled - but can it be controlled simply by voltage or pulsing with an Arduino before this circuit to get some level of control? Can this be scaled up for melting 3" shaft? 
Regulating Power Transfer
- Basic considerations are that the skin depth of heating is determined by aquare root of resistivity, inverse square root of frequency - 
- How to match impedance of load and circuit? Not easy under changing load conditions. See overview and development of active LLC control in Polish paper- 
- Match imedance of load, which has L, R, C components
- Variables - f, v/I, L, R, C
- Can change f with microcontroller; input V with microcontroller; variable active controlled inductor bank with servo, variable R, switching on C banks?
- Is the problem statement how to control each of these, or the detection logic for feedback?