| percy |
Below is an impedance chart of a ~1.9mh inductor. Blue is reactance, Yellow is phase. This was measured using Speaker Workshop (passive component measurement feature).
Typically when I measure a capacitor or a resistor I get a dead straight line for phase (yellow) at 0° for a resistor and -90° for a capacitor. But when I measure an inductor the phase gets skewed like shown in the chart. It starts shifting towards 0 in the low frequency range. Why is that ? My guess is that it could be because of the DCR of the inductor.
I get similar results when I measure high value (1000uf+) capacitors. The phase starts shifting towards 0 in the high frequency range. Again, ESR ?
What do you guys think of an explanation for this ? |
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| soongsc |
| How does your measurement.calib look? |
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| sreten |
Hi,
Think about it. What would a speaker inductor that could
maintain 90 degrees phase shift at 10 Hz look like ?
How low would its DCR need to be ? How big would the
core need to be for the current from your drive voltage ?
:)/sreten. |
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| percy |
| quote: | Originally posted by soongsc
How does your measurement.calib look? |
flat
| quote: | Originally posted by sreten
Hi,
Think about it. What would a speaker inductor that could
maintain 90 degrees phase shift at 10 Hz look like ?
How low would its DCR need to be ? How big would the
core need to be for the current from your drive voltage ?
:)/sreten. |
so it IS about dcr/esr, right ? |
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| Tweeker |
ESR in the main and interwinding capacitance?
| quote: | | I get similar results when I measure high value (1000uf+) capacitors. The phase starts shifting towards 0 in the high frequency range. Again, ESR ? |
This is in part an effect of the capacitors ESL. Special measures must be taken for a capacitor to be effective at high frequencies. |
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