PC and monitor standby power?

[dr.s.lartius]

I did not; I was asking about the power in watts, not the cost. To get the true cost, one must remember that the dissipation in question is a humble contribution to the room heating

To answer other respondents :

Amitech MM Lite PC 1851, Philips monitor type unknown. Windows 7 is in the "Turn off" state at night.

Speakers - good thought. I don't recall exactly where the "manual" for that pair is, but I do know where that for a replacement pair should be - no such information supplied on sealed retail purchase - Creative A60 2.0.

Some respondents wrote about buying a digital wattmeter - surely not the type of advice for news:uk-d-i-y, since one can make a digital wattmeter from the sort of electronic components that became available a generation or more ago.

I used "likely" to indicate that I just wanted approximate probable figures.

[Johnny B Good]

It's common practice amongst the manufacturers of active PC speakers to fit the on/off switch on the low voltage secondary side of the mains transformer. This leaves the transformer losses (hysteresis in the core and some I squared R loss in the primary due to magnetisation current) still drawing power off the mains supply which can be dismayingly high (4 watts or so in my case with a decently sized "Target" TRG-S320 stereo PC speaker pair).

I've been replacing the 'innards' of my desktop PC's ATX PSU, every 4 or

5 years as they wear out, with 'innards' cannibalised from new ATX PSU's simply to retain the mains isolator switch and the 'Aux' monitor power socket which it also controls just so I can shut off these parasitic loads after the OS shuts the PC down (a total of 8 to 10 watts worth).

Refurbishing, rather than replacing, the PSU also saves me having to 're- customise' the ventilation grille-work which most ATX PSUs typically compromise the efficacy of the PSU cooling fan as the sole means of adequate cooling for a well ventilated Desktop tower case housing a sub-150W peak demand PC system (I have a very quiet desktop PC that keeps its cool - in more ways than one :-).

Human or technology 'generations'? :-)

Most DIYers think it's sufficient to buy their tools 'ready made' rather than design and build their own DMMs or digital watt meters, especially when it's likely to cost more just to buy the parts than to buy a suitable 'off-the-shelf' ready made test meter (£9.99 in the case of the N67FU I recommended as suitable to making such measurements). You're talking about "Extreme DIY", a branch of the hobby that most contributors here would regard as a completely OTT approach to the gentle art of DIY. :-)

Well, apart from my overlooking a potentially significant PC Speaker load, I gave you exactly the sort of answer you were looking for. I'm feeling a little 'affronted' that you failed to thank me by name. :-(

:-)

[dr.s.lartius]

Human.

Agreed. The components in question must have cost well over £9.99 in the money of those days, let alone the auxiliary equipment. But the accuracy greatly exceeded that of the N67FU. But maybe I can get an N67FU using so meone else's shoe-leather.

[Johnny B Good]

And, then some! Inflation alone would make it the equivilent of £100 in the early to mid 80s but it would likely have cost five to ten times more again simply because the electronic components were so relatively costly at that early stage of the game.

Such extreme accuracy (better than a tenth of a watt) would simply be wasted in such an application as this. I can be confident that, unlike the 'affordable' sub ten quid 'energy monitors being sold by Aldi (the infamous DEM1379) and a similar unit from "Machine Mart" a decade or so ago which could show anything from zero to 20 watts on a 10 watt router or cable modem load, the N67FU *does* correctly read[1] to within a tenth of a watt, even on sub 2 watt smpsu wallwart loads since the readings correlate to within a tenth of a watt as best as I can interpolate the 2 watt graduations on the mirror backed 100W scale of my trusty Metrawatt analogue watt meter[2] when using a jeweler's loupe. Trust me on this, I have the means to cross check without reliance on potentially suspect electronic reference measuring kit. :-)

[1] After my disappointing experiences with cheap 'digital watt meters' (which tarred all such 'affordable' digital energy monitors for the next decade afaiwc), I was flabbergasted at the unexpected accuracy of this energy monitor (aka digital watt meter) as I was, likewise with its slightly more expensive cousin, the 2000MU-UK (an anglicised "Kill-A- Watt" for those of the American persuasion). For once, it made a pleasant change that the 2 or 3 quid each that I spent in my local flea market *wasn't* a total and utter waste. [2] I bought this rather nice watt meter at a radio ham rally nearly thirty years ago. The 35 quid asking price almost put me off (I couldn't haggle the trader down) but I knew I was looking at something almost unique in the world of electrical measuring instruments so I 'squandered' my 35 quid without too much 'soul searching'.

I knew such watt meters were pretty scarce but only discovered, after googling for more info on this meter just a few years back, that they are in fact, as rare as "rocking horse shit"(tm).

Gone at last, were the days when I could only guess at the power consumption of various electrical and electronic mains powered 'appliances'. However at that time, I didn't realise just how useful a diagnostic aid it was going to become in the art of diagnosing and repairing desktop and laptop computers when I eventually quit my 'day job' to build, sell and repair PCs 'full time'.