What's gets me is that I didn't think of this snake oil first. Had I thought of it first I could own a PTI H-MASER by now. :- )
-Brian, WA1ZMS -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Didier Juges Sent: Tuesday, June 18, 2013 10:01 PM To: [email protected]; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP and other equipment failure "audiophile outlets" You've got to be kidding but not even. At least, nobody is forcing anybody to buy them... Didier Peter Gottlieb <[email protected]> wrote: >The current distortion from simple transformer-rectifier-capacitor >power supplies contains a lot of third harmonic content. In a 3 phase >system (as are all distribution systems for commercial and industrial) >the third harmonic ADDS in the neutral, or creates circulating currents >in a delta configuration. These currents, as you mention, can get very >large and were the cause of many > >transformer explosions in cities as these power supplies became common. > The >transformer designs had to be improved, but the PFC supplies make a big >difference. > >How many of you have looked at the power line waveform, especially in >an industrial or commercial area? Doesn't look much like a sine wave, >does it? So it's pretty funny to see audiophile outlets >(http://www.dedicatedaudio.com/power_outlets). > >Peter > > > > >On 6/15/2013 6:56 PM, stan, W1LE wrote: >> PFC to me is power factor correction, not only the classical power >factor to >> minimize (VAR) volt-amp reactive component, but also to remove the >> harmonic load current imposd on the >electrical power >> system. >> A '90's onward technique. in th 80's and 90's without the harmonic >load >> current reduction and having >> a few 100 end items of equipment, each withtheir own a switch mode >power >> supplly, >> it was not uncommon to find hundreds of amps of the third harmonc on >neutra, >> in the electrical power distribution system. >> >> Could be a serious EMC problem if you were dealing with voice grade >channels. >> And people safety issues. >> >> Stan, W1LE Cape Cod >> >> >> >> On 15-Jun-13 5:52 PM, J. L. Trantham wrote: >>> Sorry for the interruption but what is 'PFC'? >>> >>> Thanks. >>> >>> Joe >>> >>> -----Original Message----- >>> From: [email protected] [mailto:[email protected]] >On >>> Behalf Of Poul-Henning Kamp >>> Sent: Saturday, June 15, 2013 4:09 PM >>> To: Robert Atkinson; Discussion of precise time and frequency >measurement >>> Cc: Perry Sandeen >>> Subject: Re: [time-nuts] HP and other equipment failure >>> >>> In message ><[email protected]>, >>> Robert Atkinson writes: >>> >>>> While I agree with everything else you say, you CAN have too much >>>> filter capacitance. At least where dc rectifier / filter >(smoothing) >>>> circuits are concerned. Increasing C causes increased ripple >current >>>> [...] >>> And ripple current can be a major source of power-line frequency >noise in >>> all electronics. >>> >>> The main reason why switchmode power-supplies today (can) outperform >linear >>> power supplies with respect to noise, is because the legally >mandated PFC >>> correction eliminates the bridge-rectifier ripple harmonics. >>> >>> I would not hessitate to use a good quality switchmode to replace >the linear >>> supply in a HP5370B. >>> >>> I did some experiments a couple of years ago, with an >audio-amplifier: >>> I put a standard PFC corrector chip on the secondary side of the >trafo. >>> >>> The overall result was not satisfactory, but the 50 Hz "sneer" >>> we all know and hate was absent, and the "Tzoing!!!!!" power-on >mechanical >>> shock from the trafo was also eliminated, as was the consequent >dimming of >>> the lights ;-) >>> >>> The main reason not to do this, is that you need some physically >gargantuan >>> coils for a 10A+ PFC-switcher. >>> >>> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 10.0.1432 / Virus Database: 3199/5913 - Release Date: >06/15/13 >> >> > >_______________________________________________ >time-nuts mailing list -- [email protected] To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
