Not NO3 pressure and humidity too, there;s one on the lab running now not s ure what he's doing but this version involves pumping water about, I had to corden it off this moring as we had a repeat lab on which I wasnlt expecti ng to happen.
So idea sort of thinmg for a Rpi running a PC 24/7 to do this seems over ki ll I had 3 aquariums once I didn't need a PC to run them. Although it would make an interesting student project but I think we'd expe ct them to use some for of embeded system rather than a PC.
True but I don't think a PC will alter that much. People have kept fish far longer than PCs have existed, so it's quite possi le to look after such fish without a PC. I've yet to see an aquarium shop u se such a system. I alo think that what's usedc in aquaruims such as heaters, filters, airpum ps, lights are all far more relible than the average PC, which means I;d be more worried about a PC crashing than a heater failing.
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.
The problem was more to do with relatively narrow conduction angles in the ATX PSU's HT module (the full bridge rectifier and the (typically a pair of series connected 200 to 250v rated electrolytic) HT smoothing caps) rather than the more traditional inductive loadings where there is a lagging current component. Early smpsus had very little in the way of PFC then later PC PSUs started adding passive PFC (an inductor to extend the conduction angle) followed by active PFC circuitry which has improved the PF to almost unity.
Strangely, I noted a PF of 60 when I was testing the inverter genset with the SmartUPS2000 powering a mere 175 watts or so's worth of load, representing just 12% of its 1500W rated maximum. The culprit is down to the whopping 2 x 4700nF's worth of input capacitance which forms part of its monitoring circuitry as best as I can guess from the circuit schematics.
I know this from my experience with a conventional 2.8KVA genset that kept overvolting to this capacitive loading (a test with a single 4700nF fluorescent lamp PFC capacitor to smooth out the HF slot ripple had been more than enough to send the genset's 230vac output north of the 270v mark).
It turns out that relatively modest amounts of capacitive loading on a conventional emergency generator will induce self excitation into the rotor which the AVR has no control of whatsoever. The UPS when in pass- through imposed twice that 270v inducing capacitance on the genset's output causing the UPS to switch to battery power, disconnecting the capacitors, causing the genset voltage to drop back to 230v, allowing the UPS to accept the voltage as good once again and sync back up and attempt to pass the 'good power' through to the load, inducing the next overvolting cycle ad infinitum until I switched back to genuine mains voltage.
Getting the SmartUPS2000 to pass that cheap (99 quid!) Lidl purchased Parkside inverter genset's power through to the load without drama was a landmark result in my quest to upgrade the UPS protection to a configuration that would provide hours and hours of autonomy way in excess of even several thousand pound's worth of batteries could provide.
Initially, I was merely interested in buying such a low KVA inverter genset to prove that modestly rated gensets in the range 1 to 3KVA, rather than BFO monsters in the 20 to 50KVA range, could only serve this purpose if they were of the inverter genset class.
I didn't want to blow some 600 quid or so on a 3KVA inverter genset without at least proving the point. Now that the only incandescent lamps left in the house are fridge, freezer, cooker hood and oven lamps (all fed off a ring main supply), I reckon that little genny just might prove sufficient to keep not only my IT kit running but also keep the lights, the main telly, the CH pump, the fridge and, with manual power management, the freezer running. I might not need to upgrade but only testing will say.
A brick 'Dog Kennel' for the genset looks like my next DIY project - I don't want to annoy my neighbours too much by running a still noisy generator (its only about 6 to 10dB quieter than its predecessor at best) for protracted test periods.
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
There's a wikipedia entry for those P3 International based energy monitoring devices.
The Prodigit Model 2000MU-UK as shown in the second picture down, used to be sold by Maplin[1]. 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 useless!
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. :-)
[1] 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).
ot sure what he's doing but this version involves pumping water about, I ha d to corden it off this moring as we had a repeat lab on which I wasnlt exp ecting to happen.
r kill I had 3 aquariums once I didn't need a PC to run them.
expect them to use some for of embeded system rather than a PC.
ossile to look after such fish without a PC. I've yet to see an aquarium sh op use such a system.
rpumps, lights are all far more relible than the average PC, which means I; d be more worried about a PC crashing than a heater failing.
Yes I do, I just don;t see the point of monitoring something yuo don;t 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.
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.
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