On Monday, 30 April 2018 14:23:57 UTC+1, dennis@home wrote:
have control of and using a PC to do it.
Well when I had 3 aquariums I didnlt have any computer connected to them as
I didnlt need to. The tank heaters seemed to managed with their internal t
hermostats. The lighting used to come on/off via timers everything else rem
ained on, so I can;t work out what there is to monitor perhaps PH levels bu
t they didn;t seem to cause probles.
Now an aquaium could be controlled by a PC which could in theory could swit
ch the lights off and on and it could measure the water temp, and turn on/o
ff a none themostatically controlled heater, but I didn't see the point.
I can't think of anything else that a PC could monitor, that would be worth
monitoring. I've never seen an aquarioum shop use a computer to control th
eir tasnks they all seem to have their own dedicated bits.
Well it ain't me.
How do you measure ammonia in a tank. I used a sort of litmus paper.
On Monday, 30 April 2018 21:09:44 UTC+1, dennis@home wrote:
t have control of and using a PC to do it.
m as I didnlt need to. The tank heaters seemed to managed with their intern
al thermostats. The lighting used to come on/off via timers everything else
remained on, so I can;t work out what there is to monitor perhaps PH level
s but they didn;t seem to cause probles.
switch the lights off and on and it could measure the water temp, and turn
on/off a none themostatically controlled heater, but I didn't see the point
orth monitoring. I've never seen an aquarioum shop use a computer to contro
l their tasnks they all seem to have their own dedicated bits.
OK then how do you monitor pH levels in your tank using your PC.
How do you measure temerature levels in your tank using your PC.
On Monday, 30 April 2018 21:37:35 UTC+1, Rod Speed wrote:
The heaters in aquariums are meant to run like that.
My shortest life one must have lasted at least 4 years before it went fault
My air and water pumps out lasted my interest in keeping aquariums which wa
s from 1988 until around 1998.
On Tuesday, 1 May 2018 13:28:52 UTC+1, dennis@home wrote:
don't remmeber .
Zero, I didn't use coral, mine were fresh water aquarium fish rather than seawater.
But it still doesnlt explain how monitoring with a PC changes anything , people have been keeping such fish for far longer than PCs have been around.
On Thu, 26 Apr 2018 15:07:08 +0100, Andy Burns wrote:
If you're using an APC SmartUPS700, you can measure the input power and
calculate the PC consumption by subtracting the 20W maintainence
consumption after allowing the battery pack to recover from the shock of
the interruption. Half an hour or so should suffice (or else disconnect
the battery pack whilst you take a wattage reading). You can hot swap the
battery pack in this model - there's no difference between a fully
charged battery and a disconnected battery in the maintainence
consumption readings to within *less* than a tenth of a watt.
35W is a remarkably low power consumption for a desktop even allowing
that the monitor may be in standby screensaver mode. My desktop idles at
around 86W with the monitor taking another 30W or so and the speakers a
further 4W. I tend to leave the PC on permanently. My only concession to
energy saving being that I switch the monitor off before I go to bed. :-)
I got a chance to measure "The Office" energy consumption last Sunday
when I was testing a 1KVA Parkside inverter genset with the SmartUPS2000
currently (at long last, once more) serving the "Protected Mains Sockets"
that feed said desktop, a NAS box, GBe switch and an old Linksys router
acting as a WAP. With the monitor switched off, the consumption settled
down to about 206W after the batteries had recovered from the brief
outage incurred by the change-over to genset power.
Around about 28W of this being the maintainence consumption of the 2KVA
rated UPS when fed by the 233vac genset output (it goes up to 32/33W when
on the normal 240 to 245v mains supply). Not covered by the main UPS is
the 10W or so consumption of the VM SH2 that resides in the basement, so
all in all, a total minimum overnight consumption in the region of 220W
for the IT kit alone.
It idles quiet well for a 3.6GHz 8xhyperthread xeon with 32GB and a
lowish rx550 GPU, the DVB-S2 tuners drag a bit of power for the LNBs
when they're in use, has its own PCIe power connector like a GPU.
That's with only the SSD in use, it has 9 SATA hard drives that I
selectively dismount and spin-down (especially at night I dislike the
I've never seen the PSU supply more than half its 550W, maybe at boot
time with all drives spinning up.
The KVM was switched away from the tower PC to the laptop, the dock for
that and the monitor do run off the UPS, but were not supplied through
On Fri, 27 Apr 2018 04:37:51 +0100, Andy Burns wrote:
That's impressively economic! That's just a mere 5 watts more than my 13
year old Acer Aspire 3660 laptop running under Linux Mint (no 32 bit
distro I've tried properly supports the chipset so no low power idling or
programmed shutdown options).
I've half a mind to restore the win2k setup I originally installed as a
replacement to the PoS winXP MCE it had originally been afflicted with
just a week after buying it. It idles at a mere 20W with the lid down
when acting as a single channel PVR with a USB DVB-T stick plugged in
which would otherwise let me record 3 BBC channels simultaneously with
padding overlaps using Kaffeine under Linux).
I don't really need an emergency PVR any more so it just sits there,
shut down, connected to its charging brick as it has been for the past 13
years with the battery still good for 80% of its original capacity.
That's a hell of a drive count for one desktop PC. I've got a couple of
HDDs and an SSD along with a couple of DVD Writers which, TBH, never get
used so could be removed to save a watt or three but which ICBA doing.
The rest of my storage needs are served by a NAS4Free box with a 3
drive, always spinning, JBOD connected to a GBe switch. I removed one of
the four drives a few months ago to save what I hoped would be 7 watts
but turned out to be a mere 3 watts which brought the consumption of the
server plus its dedicated BackUPS500 down to just on the 50W mark
(according to the UK/European version of the Kill-A-Watt, aka a "2000MU-
UK" plug-in Power Monitor that I keep permanently in line)
Digital watt meters are pretty rubbish at *registering* start up power
consumption surges. Displaying a peak reading after the event just
doesn't cut it when you're trying to identify AMD SKT7 cpus with shorted
out cores from a box of 'pulls' bought from a flea market trader,
*without* burning out the VRM on the test MoBo - you need a proper
analogue watt meter and a speedy finger poised over the PSU's mains
switch for that task. :-)
"Kill-A-Watt" is the model name for the American Plug-in Energy
Consumption meter. Presumably you were referring to a 240v version such
as that 2000MU-UK I mentioned above.
History is that the predecessor motherboard had a PCI-X slot with an
8xSATA JBOD controller and I used linux with 2x750GB in RAID0 plus
6x750GB in RAID5 for running various VMs under Xen.
So they stay in the tower case and get occasional use testing ditros,
while it has additional drive slots with a 64GB SSD and a 4TB disk as
its main disks, at the moment.
Yes, and I see the manufacturer *does* say it measures true RMS
On Sat, 28 Apr 2018 07:25:06 +0100, Andy Burns wrote:
There's a wikipedia entry for those P3 International based energy
monitoring devices. <https://en.wikipedia.org/wiki/Kill_A_Watt>
The Prodigit Model 2000MU-UK as shown in the second picture down, used
to be sold by Maplin. Mine was actually a flea market acquisition from
a trader with the nickname "Maplin Man" on account of most of his stock
being Maplin's "returns" he'd bought at auctions.
I think I paid a fiver for mine and on another visit 8 quid for a couple
of "Maplin Gadget N67FU" plug-in energy monitors one of which failed
after a year or three's use and still sits on my bench partly stripped
down waiting for me to try a few things out by way of a repair.
It had simply started giving nonsense readings for no apparent reason.
Its twin is still working fine some 12 months on giving remarkably
accurate readings right down to a tenth of a watt which track the
MetraWatt analogue readings (as does the 2000MU-UK meter) to within a
couple of percent all the way through to the 3KW limit.
I think it must be the 2000MU-UK that only shows to tenths of a watt
when above the 1W mark with anything less than one (or possibly a half)
watt showing a zero reading (probably the reason I chose it as a
permanent consumption monitor for my NAS box and UPS). The N67FU meters
have more functions but the 2000MU-UK has an easier to read display.
The only reason I can be so confident in their accuracy (to within +/-3%
of their VA and wattage readings at any rate) is simply down to my having
an old fashioned analogue watt meter to hand, namely that MetraWatt unit
I mentioned which I'd bought 2nd hand at a radio ham rally some 30 odd
years ago for the princely sum of 35 quid (far more than I'd have usually
paid for similar test kit at the time).
As far as those two digital watt meters are concerned, provided you
haven't got a faulty example, I can vouch for their accuracy claims
(before one of the N67FUs went faulty, they were both giving matching
readings between each other, the 2000MU-UK and the Metrawatt to well
within their specified tolerances). The quality of these meters (and
presumably that of later models) has improved out of all recognition over
that of the earliest plug-in "Energy Monitoring" gadgets being missold
some 15 or so years back by the likes of MachineMart, Netto, Aldi and Lidl
to their more trusting clientèle.
Those early 'wattmeters' could typically show anywhere from a zero to a
twenty watt reading on an 11W CFL or stuff like ethernet switches and
modem/routers and such like. Readings which, quite frankly, couldn't even
be accounted for by assuming they were displaying VA readings as faked
wattage readings! These early examples were so bad, they were less than
I can well understand why anyone, who's ever experienced the inaccuracy
of these first generation Wattmeters, would be cynical of the later plug-
in "Energy Consumption Monitors". I certainly was until I tried them for
myself against a trustworthy analogue watt meter and then each other.
I must have had a sense of the Metrawatt's rarity to part with so much
cash for what seems to now be a 'Priceless' artefact of the 70s and 80s -
they seem to be as rare as rocking horse shit these days. In truth, I
thought I'd only see a limited use for it in measuring the wattages of
the various bits of kit I had to hand.
Surprisingly, I discovered that it even works with DC voltage supplies!
The low voltage of 12v kit means the readings are limited to a max of
quarter scale deflection without modding the voltage multiplier resistor
to recalibrate to a 20v factor option - not worth it when you can simply
multiply the current and voltage readings of a DMM to get the same
result. When I started repairing PCs for a living, it proved to be a
surprisingly useful diagnostic aid. :-)
 Looking at the detailed spec offered on the Maplin web page, I
noticed the same confusion between watts and VA in regard of the meter's
own power consumption figures. The 120v Kill-A-Watt spec said "10W"
whilst the figure quoted for the 2000MU-UK was "20W". Clearly, this was
the VA figure for a half watt device using a 'lossless capacitor dropper'
supply (half a watt as read, with the aid of a jeweller’s loupe, from the
Metrawatt's mirror backed scale).
On Thu, 26 Apr 2018 14:13:53 +0100, Andy Burns wrote:
That's enough bollocks between Martin Brown's claim that recent plug in
energy monitors are inaccurate on small sub 10W loads and only read to
the nearest watt +/- 10W (true of the very first sub ten quid Machinemart/
Netto/Aldi units from over a decade ago), and this business you've just
mentioned of a line interactive UPS somehow magically distorting the
mains voltage waveform just by selecting a lower voltage tap on its mains
transformer to restore the mains voltage back to 240v, so I'd like to
dispel these myths.
As mentioned, it's been a good decade since useless plug in energy
monitors were last miss-sold to the general public. Any current plug in
energy monitors sold during the past 6 or 7 years (maybe longer) have
proven to be remarkably accurate to within +/-3% of VA and Wattage
readings (and, therefore of necessity, to within +/-1.5% of voltage and
They all display readings to a tenth of a watt resolution (although one
model I have only does this for readings above 1W) and display to a
maximum of 3120W or so (I noticed a 5 quid model on Amazon claiming it
would only read to a maximum of 2998W before cutting out).
These "Plug in Energy Monitors"(aka fancy digital watt meters) have
improved beyond all recognition since such devices first appeared some 15
years back. IOW, they're quite a useful measuring tool to have for
checking the consumption of IT kit such as modem/routers, ethernet
switches and PCs (as well as the standby power of TV sets and USB
As for your assumption, Andy, regarding the power feed to your PC not
being the "sineyist of sine waves", well you're right (up to a point) but
not on account of the line interactive UPS bucking the voltage with its
transformer. The lack of sine wave purity originates with the mains
supply itself which can best be described as a sine wave that's had its
peaks neatly sliced off with the flat tops showing a slight down slope on
the positive peaks and vice-versa for the negative peaks.
If you can observe the mains waveform on a proper oscilloscope (or audio
captured using an audio recording app that will let you zoom in on the
recorded waveform (CoolEdit Pro or Audacity) from the output of a 5 to
15vac output wallwart transformer attenuated with a resistor network down
to half a volt rms or less to avoid overloading the line input of your
sound card), you will be able to observe this for yourself.
If you remove the mains input from the UPS whilst observing/recording
the waveform on the protected side as I've just described, you will
either see a horribly shaped squareish wave or else see a perfect sine
wave replace the slightly distorted mains voltage waveform, depending on
the quality of your UPS.
If for example, you have an APC SmartUPS, expect the quality of the
"mains waveform" to improve (I believe all APC models of "SmartUPS"
provide sine wave outputs). :-)
 Or 230v if you believe that our UK mains supply has actually been
adjusted to conform to the notional 230v rating of electrical goods sold/
manufactured throughout the whole of the EC rather than left exactly as
it always has been except for the change in the voltage tolerances
mandated by new regulations catering for the notional 230v ratings of new
The main reason I mentioned that the kill-a-watt was monitoring between
UPS and PC was that I was quite surprised the power factor was under 60
and thought someone might query it being that low. The PC has a 550W
PSU and was more or less idling at the time, maybe not ideal for
efficiency or power factor.
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