Now I have your attention (And a moving little testimonial to mIGUEL) (And it was heading [OT] anyway) On 7 Sep 97 at 20:16, Paul B. Webster wrote: > Mike Keitz wrote: > > > If the "NDT equipment" is effectively a resistor, then the solution > > for RMS power delivered > > I know I am being picky, but can we please refrain from this > fetish of > referring to the *meaningless* term "RMS power"? Use of this term > indicates an essential lack of grasp of the situation in question! > Let's just look at it calmly: > > An RMS Voltage or Current is ONE WHICH results in a certain MEAN > power. In a steady-state situation, we can assume we are referring > to the heating effect integrated over a large number of cycles and > consider the integral over one half or full cycle. If the load is > essentially resistive, it is straightforward to perform this > integral as Mike noted: Isn't this only true for sinewave? (Admittedly, we are dealing with sinewaves, but you raised the 'picky' issue) > Note that I keep referring to power, since that is what lights the > lamps, not RMS voltage. Even then, the effective lamp brightness is > not a linear function. Please however FORGET RMS and forget voltage > (other than the RMS value of the sinewave going in, used for > full-scaling)! Still think rms is mean, but mean is not necessarily rms - depends on waveform. > > To calculate the phase table, simply match (cos(pi*x)+1)/2 which > is > scaled from 0 to 1 (proportional power); against values of x from 0 > to 1 (phase angle scaled to a half cycle). I would reckon QBASIC > the easiest tool to use for this, NOT C. Perhaps QBASIC fits the > description of "a general-purpose math package" anyway? I almost agree here. Putting c together for a quickie table generator is ridiculous. QBasic not much better. Use a spreadsheet - they're tables just begging to be filled in! If the function gets too complex, then Application Basic is waiting in the wings. MikeS