How to scope the power network?

[Martin Naef]

Hi Joost

On 19.04.2012 12:13, Joost Schuttelaar wrote:
>> Depends on what exactly you're trying to measure. If you look at
>> short interruptions or voltage sag/spikes, the transformer should
>> do fine. But keep in mind that a standard transformer will act as a
>> filter on its own, so trying to figure out precise harmonics might
>> not be very successful.
>
> A non-switched transformer, hooked up to a multimeter with voltage
> showing. That would work to see voltage dips in the mains, right?

Long-term dips, yes. My multimeter (not particularly fancy, about 20 
years old...) measures up to 750V AC, so no transformer needed at all. 
However, it has relatively long integration times, so I doubt that you 
could safely catch short drop-outs. Longer drop outs - well, just watch 
the light bulbs...

BTW: When you measured the waveform that you posted, did you put a bit 
of resistive load on the low-voltage line?

Martin