>
>Problem: I need to make the power output linear with respect to the encoder
>setting, ie when the encoder is set to 10% the output power needs to be
>10%.
>As you know, when controlling the phase angle of firing the power is not
>linear
>as it follows an 'S' type of response - a change in time before or after
>the peak
>of the sinewave results in a small change in power control, whereas a
>change
>in time firing near to the peak of the sinewave results in a vary large
>change in
>power output.
>
>Has anyone got a formula to calculate the change in power compared to the
>change in time in firing within the phase so as to allow me to linearise
>the
>response - or do you know of any articles which could point the way.
>
>Many thanks
>
>Stephen H Alsop    email: steve@s.ssystems.easynet.co.uk
>S&S Systems Ltd   www: http://easyweb.easynet.co.uk/~s.ssystems
>
I will soon be working on a similar project and I will need that
information as well. Someone on the piclist described solving this problem
by using a lookup table, but he didn't say how he calculated the correction
factors.