On 03/30/2010 03:02 PM, Jones Beene wrote: > -----Original Message----- > From: Stephen A. Lawrence > > Do you by any chance have a URL? > > http://groups.yahoo.com/group/aH-gen
Thanks; I will check that out. (In fact I think you already posted that link, but I didn't realize what it was. Duh...) ... > SL: He's using the Fluke 123 "true RMS" digital scope, with graphical > output, to measure amps and volts. If there's any division by twenty going > on it's not documented on that page. > > Not in 2005-6, when the erroneous claims were being heavily promoted. He was > using a clamp-on and manually dividing by 20. If JLN was reading peak amps and dividing by 20 to get RMS amps, then he was off by a factor of about 4.5. Square output with a 5% duty cycle has an RMS value of 1/sqrt(20) times the peak value. If he was starting with an *average* amp value and dividing *that* by twenty, then, since average current is already a factor of 4.5 smaller than RMS current in this case, that would have been off by a factor of about 90. But neither of these scenarios produces a result which is off by a factor of 20. To achieve that, he'd need to take an RMS current reading and then divide it by an additional factor of 20. > > The problem was, back in 2005-6 the false claim of COP > 20 was never > retracted while there was still major interest, but Gifnet has toned down > everything now, and perhaps there could be something to it ... now that > Naudin has apparently learned to measure input. But he has still not > retracted from his own site, apparently. It is on his own site that he shows the "true RMS" measurements done with the Fluke 123 which support his claim of a COP > 20. The links I included earlier, which were to images showing the output of the Fluke, were for several runs which produced varying COPs of near or over 20. If there is something there which should be retracted it's not obvious what it is. The Fluke uses a clamp-on current probe. That, by itself, isn't grounds for throwing it out, however; according to Fluke's specifications for the meter, it can produce "true RMS" values for current as well as voltage. It's possible that detailed knowledge of how JLN measured the current could show his input power to be 'way off, but that's just speculation, of course. > > Jones > > >
