Ok,
The final circuitboard is ready.
I added the switches. In stead of 10 options, i use 5.
So, the dipswitches have a double function.
If you use 1 dipswitchsetting, you have a dutycycle of 10%
If you use 2 switchessettings, you have a dutycycle of 20% etc etc.
So, you can can play with fixed dutycycles between 0 and 50 with use of 5 switchessettings.
If you use the 10% and start with the middle dipswitch setting. (nr.3 of the switch) you will have the
possibility to change phase up and down in steps of 10%. So max 20% up or down.
The circuit, with exception of the FETs are voltage controlled by the 7812 regulator. This means that
you can use a variable powersupply to the board. This way you can have between the 12 and 30V on the primary coils of the toroid for tuning purposes!
The frequency's are made by 1 oscillatorchip and the 3 harmonic channels are fully in sync with eachother because of that.
The base frequency is adjustable, so you can play with that as well. This means that for example you can have on channel a range from 40 till 45khz.
here moree pics!
br
Steve