Harmonics through magnetic ballasts ??

[powerplay]

I was told that magnetic ballasts create harmonic current... does an inductive ballast add harmonics, or is the harmonics caused from an incorporated capacitor within ? I was under the impresion harmonics was more af an electronic issue.

Thanks again in advance!

 

[gar]

100411-1452 EST

I looked at two different 8' Slimlines. These have quite different power factors. Both show substantial harmonic content on the current waveform. Both had a tendency to have three humps per half wave. If you did a slight running average the waveshape would be somewhat trapezoidal in shape.

At 122 V the readings using a "Kill-A-Watt" were
0.75 A, 81 W, 91 VA, 0.87 PF
0.95 A, 109 W, 117 VA, 0.94 PF

If you have or know someone with a scope and/or other instruments try some of your own measurements.

From Wikipedia

Some authors[1] define a trapezoid as a quadrilateral having exactly one pair of parallel sides, thereby excluding parallelograms.

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[gar]

100411-1521 EST

As an added point --- I think the power company might like this kind of load current to compensate for all the center peaked current from computers.

Later I will look at some combined waveforms.

This is another good area where readers might experiment.

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[gar]

100411-1710 EST

I have added an experiment:

The above results:

At 122 V the readings using a "Kill-A-Watt" were
0.75 A, 81 W, 91 VA, 0.87 PF
0.95 A, 109 W, 117 VA, 0.94 PF

Both Slimlines on at once:
1.73 A, 196 W, 213 VA, 0.92 PF

A computer with a very peak current pulse:
0.66 A, 51 W, 81 VA, 0.62 PF


Then the combination of the three:
2.22 A, 256 W, 269 VA, 0.95 PF
Still a very bad current waveform.

Thus, the combined fluorescent improved the computer PF, and the computer improved the lamp PF.

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