I will share my source code as soon as it is finished.
With MAX6675 there is a problem, that it can't read temperatures above 1023°C. So you will need to place thermocouple away little bit or buy another decoder. I recommend MAX 31855K that can read higher temperatures but if connecting with arduino you will need 5V to 3V logic converter too. There are boards available on ebay that are suitable for arduino with this decoder and logic converter too.
At the moment I've designed PCB for IGBT driver that will replace transformer and triac board. This board will allow very high currents, high switching frequency (perfect for PWM) and precise control.
I have not tested it yet, but it should work fine.
This circuit is basically converting AC to DC and modulating back to "AC" with variable frequency and is protected by optocouple. Switching frequency may be up to 50kHz at least.
It will also create huge EM pulses so it can be great for LENR I hope.
I will test this circuit later after first fueled test.