Power meters, to measure what?

Discussion in 'General Electronics Chat' started by Billy Mayo, Apr 17, 2013.

  1. Billy Mayo

    Thread Starter New Member

    Mar 24, 2013
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    Power Meters, what have you used them for , what kind of circuits?

    What were you measuring when using a power meter?
     
  2. t_n_k

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    Mar 6, 2009
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    I've used RF power meter to measure amplifier output power to load. Also used AC line power meter to measure single phase and 3-phase power.
     
  3. Billy Mayo

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    Mar 24, 2013
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    Measuring what with a power meter for single phase and 3 phase
     
  4. WBahn

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    Mar 31, 2012
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    Circuits in which I wanted to know how much power was being used.

    Uh... power?

    Could you provide a little bit more detail on what you are trying to find out?
     
  5. WBahn

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    Measuring power. What else would you be measuring?

    Are you trying to find out how a power meter works? What kind of power it is measuring?

    Throw us a bone!
     
  6. BillB3857

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    Feb 28, 2009
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    Dynamometer to measure output power of BLDC electric motors.
     
  7. Billy Mayo

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    Mar 24, 2013
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    Yes give me examples of how u used power meters and what were u measuring? The power of what kind of signals? The power meter measures harmonics, for what?
     
  8. WBahn

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    Not all power meters measure harmonics. But if they do then you get a feel for how "clean" the power is, though you need to take measurements under different conditions to determine if the incoming power is dirty or if your load is dirty.
     
  9. Billy Mayo

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    Mar 24, 2013
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    If the incoming is dirty the harmonics would be what?

    If the the load is dirty the harmonics would be what?
     
  10. WBahn

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    You can't tell. That's why I said that you have to made additional measurements. If you disconnect the load and connect a resistive load instead and the meter still shows harmonics, guess which is dirty.
     
  11. Billy Mayo

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    Mar 24, 2013
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    The resistive load is dirty?

    What harmonics are clean and what harmonics are dirty?

    Are the clean harmonics 1,3,5,8?
    the dirty harmonics 2,4,6,7?

    The AC outlet from the wall has harmonics too right?
     
  12. Billy Mayo

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    Mar 24, 2013
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    The AC outlet is 60 hz

    The harmonics should be what for a clean AC outlet 60hz signal?
     
  13. WBahn

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    Before I know how best to explain, I need to know whether you understand what harmonics are. Do you? Please briefly describe what you believe them to be.
     
  14. WBahn

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    Any linear load is going to be clean.

    Dirty means that it has harmonics at all. The more energy in the harmonics, the dirtier it is.

    1 is not a harmonic, it is the fundamental.
     
  15. t_n_k

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    Referring back to the OP's original question (vague as it is) they might be distracted somewhat from the broader purposes of power measurement as applied to AC power systems. The intent of such measurement is surely not solely to determine power quality. :confused:
     
  16. WBahn

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    True, however note that it was the OP that specifically asked about harmonics. The bottom line is that it is extremely unclear just what the context of the OP's questions are. So do we try to answer in broad, general terms or in very narrow specific terms. I don't know the best answer to that.
     
  17. studiot

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    Nov 9, 2007
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    I guess from the text of the first post that this was a school 'project' question - to find out about the uses of power meters.

    The OP needs to come clean about the detail.
     
  18. Billy Mayo

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    Mar 24, 2013
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    The output of a dc to ac invertor has harmonics going to a non linear load. The 7th harmonic is the most important one why? The ac waveform on the output of the invertor looks fussy or has fine hairs on the ac sine waveform these are the harmonics. Non linear loads have harmonics?
     
  19. WBahn

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    Okay, I'm done. Until you give some meaningful context for these seemingly random questions, you are on your own as far is I'm concerned.
     
  20. Billy Mayo

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    Mar 24, 2013
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    What do u need to know?
     
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