[time-nuts] Line Voltage [Was: Anyone (ideally in the UK) ...]

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 1 Jan 2017 11:10, "Hal Murray" <hmurray at megapathdsl.net> wrote:
>
> The nice thing about the APC units is that they are close to free if you
are
> already going to purchase a UPS.
>
> I agree that something like the Dranetz 658 would be better, but a quick
peek
> at eBay shows prices far beyond what I'm willing to pay.
>
> > What's the sample rate on your APC UPS?
>
> I don't know what the internal sampling rate is.  The API is
>   tell me the current voltage
>   tell me the lowest voltage since the last time I asked
>   tell me the highest voltage since the last time I asked

Em, not a lot. My handheld true RMS Tektronix can give me the average. (One
assumes an average of RMS values).

> I have a hack that reads as fast as it can.  If nothing interesting has
> happened, it adds a line to the log file every 5 minutes.

Again,  I think if attending presenting data for others,  one wants to
avoid hacks like that. One can always post-proces to indicate the points of
particular interest.
My biggest problem is that it is not very practical to log data at the
incoming point, which is just above my back door.  If I lived on my own,  I
could set up equipment easily to do this. But sharing a house with a my
wife and a large German Shepherd dog, it is not practical to do it with the
equipment I have.

I think measuring voltage elsewhere would give someone more reason to
question its accuracy.  In my case, measuring in my lab would almost
certainly give a power supply voltage lower than that coming in.

Anyway,  short term I will use a variac to lower the voltage to test
equipment with linear power supplies.  I am less concerned about equipment
with switch mode supplies.

Dave.