Some temporary notes on using the Q series steplock JavaScript calculators: =========================================================================== by Don Lancaster 3 December 2001 version2.1 copyright c 2001 by Don Lancaster and Synergetics. All commercial and media rights ~fully~ reserved. Please view http://www.tinaja.com/glib/msinprop.pdf mailto:don@tinaja.com http://www.tinaja.com/magsn01.asp for further support (0) Always start with the Steplock-28Q calculator since it often will give you the "best" results. (1) Note that the fundamental amplitude is a normalized PEAK value that is porportional to the applied dc supply voltage. The harmonic values are all RELATIVE to the fundamental amplitude. Note further that ONLY the THD is expressed as a percentage. (2) Calculators are intended for IE use and will cause errors on certain NetScape browsers. The PostScript calculator generating sourcecode can be recompiled for NetScape use, but the color "critical harmonic" autopositioning feature will be lost. (3) The second most common cause of a JavaScript error is not waiting till the load is complete before clicking any button or box. (4) "Mode Jumping" may take place on certain high amplitudes and longer sequences. Always run a reasonableness check on your pulse results. All pulses must be greater than zero but less than ninety degrees, must start before they end, must have "daylight" between themselves and their neighbor, must be sequential, and must not overlap. Total amplitude must be between 0 and 1.002. All delta triad harmonics must be less than the 10^-15 calculation noise floor. To avoid mode jumping, "sneak up" on large amplitude values by starting with smaller values and working up one amplitude step at a time. Use only the FINE ADJUST rather than the COARSE ADJUST button when doing so. (5) It takes much longer to do all eight decimal points at once, than to do one or two at a time. The reason is that if the seventh has to clean up something the sixth missed on its first pass, then it will take ten times longer. The primary use of the higher decimal points is to prove that a solution is in fact optimal. (6) If a very high or very low amplitude is slow converging, try temporarily asking for a slightly higher or lower amplitude to help it along. (7) Extremely rarely, a solution may "oscillate" between two amplitude values. The workaround is to temporarily ask for a very slightly higher or very slightly lower amplitude. Later, you return to your desired target amplitude. (8) Calculation time goes up as the FOURTH (!) power of the number of pulses in use, so longer sequences will take much longer to determine. The Delta Friendly sequences normally calculate much faster than others. (9) Certain small results may kick into scientific notation mode. You can scroll right to verify any suspiciously large answers. (10) The quantizing buttons tell you how much the magic sinewave will degrade when you limit the number of bits in your stored table lookup amplitude. Always fine adjust again when finished viewing a quantize button's results. Repeated coarser quantizing may give errors. (11) Quantizing is conservatively based upon 20 degrees being "full scale". This may be reduced on longer sequences for lower true distortions. (12) Prototype code has been significantly improved over code now on the website and awaits your funding for a rollout. Speed is increased by eliminating extra reporting, by replacing evals with direct code, by improving the Delta amplitude adjustment and the initial guess routines, and, very significantly, by eliminating unneeded continuous Delta calculations. The scientific notation flipout has also been eliminated. (13) Further significant speedup can be accomplished by linking to compiled Java or C++ code. This awaits funding. (14) There is no known theoretical limit to the number of pulses that are calculatable, but at present, zeroing out more than 200 harmonics will be slow and become unbearable beyond 400 harmonics. By applying very fancy tricks and parallel processing, 1000 zeroed harmonics can be approached. This also awaits funding. ================================================== by Don Lancaster 23 December 2001 version2.2 =================================================== (1) Released a few of the "R" series interim calculators. These are significantly faster on longer sequences (though not yet optimal). They also include an optional timer for speed studies and eliminate the "floating point" display nuisance. (2) Other calculators in the series are easily and quickly generated using the sourcecode available to partners and associates. (3) A very significant additional speedup can be made by using partial differential techniques that will allow solutions to 2000 pulses per quadrant and beyond. This awaits your funding.