[Amps] FW: Power factor correction on tube amps

[Bill Fuqua]

     Adding in the harmonics makes sense for power factor.
Not in the traditional way but in the same way that Sine wave current and 
Cosine wave voltage produces zero Watts.
Orthogonal functions, when multiplied and integrated over a full cycle 
produce a result of Zero (definition of orthogonal functions).
Harmonics are orthogonal to the fundamental frequency. So, the 60 Hz 
fundamental frequency Voltage and
the harmonics of 60 Hz current produce no power but do produce VoltAmps 
which is the RMS value of the
Voltage times the RMS value of the Current. A Fourier Series is a set of 
orthogonal functions. All the elements of
a Fourier Series are Orthogonal to each other.
    73
Bill wa4lav



At 03:39 PM 3/8/2013 -0800, Jim Brown wrote:
>On 3/7/2013 6:26 PM, KA4INM wrote:
>>So you are saying our tube HPA's hV power supplies have a near unity 
>>power factor?
>
>Thinking about your question and my reply, it occurred to me that you 
>might not be aware of how Power Factor has been redefined to include both 
>Phase Angle (the original definition) AND harmonic current.
>
>The original phase angle contribution is now called the "Displacement 
>Power Factor" and is the cosine of the angle between fundamental (50/60 
>Hz) current and voltage, the Harmonic contribution is called the" 
>Distortion Power Factor," and the the ratio of the fundamental power to 
>the total RMS power, and the "Total Power Factor" is the Displacement 
>Power Factor multiplied by the Distortion Power Factor.
>
>In the "olden days," when loads were mostly light bulbs (resistive), 
>heaters (resistors), and motors, load current tended to be a bit 
>inductive, so power factor correction meant adding parallel capacitance.
>
>Now, loads are heating (resistors, but pulsed to make them variable), 
>electronic power supplies, inductive motors, and motors with variable 
>speed controllers (which draw mains current as switching power supplies). 
>Now, power factor correction is more likely to involve the reduction of 
>harmonic current.
>
>As I understand conditions in the EU (thanks to my activity in 
>international standards work), equipment made and sold there tends to be 
>compliant with EU regulations.  EU EMC regulations do place limits on 
>Power Factor, RF Emissions, and mains Leakage Current, and they require 
>that Susceptibility to RFI be stated on the product label or data 
>sheet.  So -- since SPE amps are made in Italy, an EU country, there's a 
>good chance that they are compliant with EU regulations. Or maybe not. :)
>
>73, Jim K9YC
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