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Field measurement of harmonic distortion- how?
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Wond
Jun 27, 2021, 12:02:51 PM6/27/21
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My son has a new welder, spec'd 5% max THD input AC power. I see
Keysight has a DMM with a "relative distortion" position. Anyone used one
of these? Useful? Anyone have a favorite, or a simple method? Cheers
Keysight has a DMM with a "relative distortion" position. Anyone used one
of these? Useful? Anyone have a favorite, or a simple method? Cheers
Phil Allison
Jun 29, 2021, 1:28:22 AM6/29/21
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Wond wrote:
=============
So don't use one.
Regular mains power is gonna be fine.
..... Phil
=============
>
> My son has a new welder, spec'd 5% max THD input AC power.
>
** The welder is clearly not happy with power from a "modified square wave" DC inverter.
> My son has a new welder, spec'd 5% max THD input AC power.
>
So don't use one.
Regular mains power is gonna be fine.
..... Phil
Wond
Jun 30, 2021, 11:09:56 AM6/30/21
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types claim less THD than cheap conventional gens.
It would be interesting to see how Agilent/Keysight measure it in
their DMM. Thanks for reply.
Phil Allison
Jun 30, 2021, 7:37:55 PM6/30/21
to
Wond wrote:
==============
" Inverter generators " are pure sine wave.
The AC supply has a few percent of 3rd and 5th harmonics.
> It would be interesting to see how Agilent/Keysight measure it in
> their DMM.
** For sure.
I saw nothing on the Agilent site about it.
Can you borrow a scope to take a peek at the wave?
.... Phil
==============
>
> >> My son has a new welder, spec'd 5% max THD input AC power.
> >>
> >>
> > ** The welder is clearly not happy with power from a "modified square
> > wave" DC inverter.
>>>
--------------------
> >> My son has a new welder, spec'd 5% max THD input AC power.
> >>
> >>
> > ** The welder is clearly not happy with power from a "modified square
> > wave" DC inverter.
>>>
>
> My thinking too, but it appears from available bumf that inverter
> types claim less THD than cheap conventional gens.
** Oh dear - FYI a "DC inverter " runs off a 12 or 24V battery.
> My thinking too, but it appears from available bumf that inverter
> types claim less THD than cheap conventional gens.
" Inverter generators " are pure sine wave.
The AC supply has a few percent of 3rd and 5th harmonics.
> It would be interesting to see how Agilent/Keysight measure it in
> their DMM.
I saw nothing on the Agilent site about it.
Can you borrow a scope to take a peek at the wave?
.... Phil
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