Dear Kai,

Thanks for your reply,

I think these machines are very well calibrated at the place where they are mounted. If you have a predictable source impedance of power station, then you can manage the table in such a way, that nearly all these distortion effects are compensated.

Most of these controllers [ miyachi ] are installed by the end user themselves and there is no caliberate.. function or any other simillar function accessible to user.

If I use a caliberate function in my controller in wich controller will fire the thyristor at three firing angles.

1. Minimum.
2. Middle.
3. Maximum.

and measure the currents attained in each. Then in 8051 itself generate co-effiecients of quadratic curve using the three firing angles and currents obtained from the caliberate routine.

y=ax2+bx+c where y=welding current and x=firing angle.

For predicting firing my 8051 can use the above format equation. How about this idea?

Will it work or not? Is there any better way?

Thanks for your kind help.

Regards,
Prahlad Purohit