Interesting findings on the internet

[tggzzz]

My free-standing worktop height one uses less than 100W with the compressor motor running. Be careful if you plan to run one on a UPS; the motors don't like modified sine or square waves, they cause too many I²R losses and consequently overheat.
I'm guessing 1kW is a momentary inrush? Most UPS's/inverters can handle 2-3x rating for a few milliseconds without a problem.

I've always shied away from modified sine wave converters for that reason. I imagine they could feed TE with a modern SMPS, but there's no way I'm going to try it!

100W while idling is pretty normal; you've got a 3KVA transformer to keep energised, and if it's a consumer/low end commercial grade unit it'll be running on quite a low DC voltage so it has a lot of work to do in the primary.

My 3kW UPSs are both rack mounted pure sine inverters, 48V battery. Clearly they are intended to be used for server backups where high power is needed for a short time.

I have ~600Wh of AGM cells, which I leave disconnected and test/charge once every 3 months. Over 3 years there has been a slow decline in capacity, but they will be useful for another three years or so.

When is Hinkley Point C coming on line? When will Putin choose to expand his empire again? Answers >/dev/null.

[tautech]

Best way to prevent short term overloads triggering breakers is to fit D class (motor rated) breakers.

[Zenith]

The problem arises in two cases.

Firstly if you have a 500W UPS for a single freezer. Looks OK on paper, but doesn't work.

Secondly if there is a prolonged power cut during which the temperature of several freezers rises to, say, -15C. Then all the motors will switch on simultaneously - and might even pop a circuit breaker in the central fuse box.

Solution to the latter is obviously to unplug all but one freezer, reset the breaker/fuse, and then plug in each freezer one at a time. I've warned my daughter she might have to do that.

If all or even one of those freezers went down, and she wasn't aware of it, it would cause her enormous problems. There's a small but serious risk of that happening. I suggest you look up Freezer Alarms and Home Automation. There are commercially available solutions.

I always thought home automation was silly, seeing no value in being able to turn on a fan from your desk, rather than get up and turn it on. However I'm sure there are serious and useful applications.

[tggzzz]

If all or even one of those freezers went down, and she wasn't aware of it, it would cause her enormous problems. There's a small but serious risk of that happening. I suggest you look up Freezer Alarms and Home Automation. There are commercially available solutions.

She will always be nearby and monitoring them (standalone thermometers in each freezer) during the critical months, so she judges it as a small contained risk.

The nearest to an "surprise" issue would be if the circuit breaker tripped when they all turned on simultaneously, and there is a simple recovery path. Being aware of the possibility / cause / workaround will have to be sufficient.

I always thought home automation was silly, seeing no value in being able to turn on a fan from your desk, rather than get up and turn it on. However I'm sure there are serious and useful applications.

I've been looking for such use cases. In most cases the benefits would be marginal, and the problems caused by increased complexity and dependencies would be significant.

I've seen a few reports by "ordinary people" which indicate that has been the case for them. I expect that will gradually become more widely recognised.

The only "not have to get up" use case I've found is TV remote controls. I first solved that in 1979 with a 6ft long pole

[AVGresponding]

ISTR Big Clive mentioning a control circuit to prevent simultaneous motor startups, in one of his vids. He did a stint as a refrigeration electrician

[Zenith]

I've been looking for such use cases. In most cases the benefits would be marginal, and the problems caused by increased complexity and dependencies would be significant.

I've seen a few reports by "ordinary people" which indicate that has been the case for them. I expect that will gradually become more widely recognised.

The only "not have to get up" use case I've found is TV remote controls. I first solved that in 1979 with a 6ft long pole

https://automatedhome.com/smart-home-su ... ase-study/

I got to get me some of that Smarthome action. However, there's no point putting the cart before the horse. First I've got to have ”A large, 6-bedroom family home on four floors in rural Oxfordshire". Even then I might have other priorities.

There's definitely a market for this stuff. Argos sell smart plugs and other bits and pieces for it. It looks rather like a solution looking for a problem.

[EC8010]

I've always fantasised about a barn conversion. Living room perhaps 30' by 18' with serious loudspeakers (10 cu ft concrete bass bins buried in the floor to keep it discreet), leading to (large) electronics lab, leading to mechanical workshop with strong enough floor for Hardinge HLV lathe (2 tons) and commensurately nice accompanying machine tools, and finally two "dirty" workshops (grinders, woodbashing). Oh, and somewhere to put the bike (a red Ducati would be nice). Bathroom, kitchen and dining room to one side of living room. A couple of bedrooms upstairs, minstrel's gallery around living room (allowing high ceiling). I thought that smarthome was a bit bling. Actually, a lot bling; I'll settle for what we have.

[tggzzz]

My fantasy has been limited to a home built into the side of a west-facing hill, preferably 300ft above the sea.

Curiously, I lived that fantasy for a few days... I met someone on Santorini one November long ago, nd she invited me back to her cave with all mod cons. The terrace was the roof of the cave below.

The cave was owned by someone who spent 6 months working in Saudi, and 6 months flaked out in the cave. That struck me as a plausibly decent lifestyle.

I could probably have afforded that cave back then, but probably not now. Oh well.

[EC8010]

Ah yes, a cave would have a nice stable temperature and humidity too, making it pleasant in both summer and winter and allowing test gear to be stable. All my test gear backs onto a South-facing wall whose temperature oscillates wildly. Never thought of that when house-hunting.

[tggzzz]

Tee hee.

Given human estate agents choose to ignore even the most basic requirements[1] when you are house hunting, the chances of setting up a "must have a stable temperature" filter is unlikely .

[1] probably better now that you can get a machine to filter based on location!

[Zenith]

They are available from time to time in certain parts of the country.

https://en.wikipedia.org/wiki/Kinver_Rock_Houses

Electricity, mains water and sewage are not necessarily laid on which may make them inconvenient for TE.

I was at primary school with kids who lived in the rock houses. They were moved out and found a council house around 1959 as I recall. By then rock houses weren't considered suitable for human habitation. It was on the local TV news.

[tautech]

Ah yes, a cave would have a nice stable temperature and humidity too, making it pleasant in both summer and winter and allowing test gear to be stable. All my test gear backs onto a South-facing wall whose temperature oscillates wildly. Never thought of that when house-hunting.

Not so in the southern hemisphere.

[tggzzz]

Ah yes, a cave would have a nice stable temperature and humidity too, making it pleasant in both summer and winter and allowing test gear to be stable. All my test gear backs onto a South-facing wall whose temperature oscillates wildly. Never thought of that when house-hunting.

Not so in the southern hemisphere.

Yeah, but you are upside down and the sun goes across the sky from right to left. Unless you are in Australia where it might also be overhead and/or also go left to right.

Strange place.

[mnementh]

In yesterday's Discord, someone mentioned "The Wandering Earth II", which turned into a bit of a rabbit-hole for me; these movies are Chinese Domestic productions of Liu Cixin's other works.

That led me here: https://www.internationalaffairs.org.au ... oft-power/

And then here: https://www.internationalaffairs.org.au ... ntarctica/

And then here: https://www.internationalaffairs.org.au ... e-warfare/

Some weird people working there... thought-provoking articles with surprisingly little bundahoo.

Cheers!

mnem

[tautech]

Ah yes, a cave would have a nice stable temperature and humidity too, making it pleasant in both summer and winter and allowing test gear to be stable. All my test gear backs onto a South-facing wall whose temperature oscillates wildly. Never thought of that when house-hunting.

Not so in the southern hemisphere.

Yeah, but you are upside down and the sun goes across the sky from right to left. Unless you are in Australia where it might also be overhead and/or also go left to right.

Strange place.

Depends if you're facing north or south.

North is our warm region so the sun rises to the right and sets to the left.....almost got me lost when in Hong Kong a few years back which is north of the equator where everything is backward to us from downunder.

[EC8010]

Given human estate agents choose to ignore even the most basic requirements when you are house hunting, the chances of setting up a "must have a stable temperature" filter is unlikely.

It was bad enough coping with what Sue described to estate agent as my "special needs" (a large living room with decent acoustics). One house we went to was lovely in terms of its condition; its owner had made the conservatory himself and his woodworking was beautiful, as was all his other work around the house; I told him what I thought of his work. But it was a three bedroom house extended to five, so the rooms were small. This place has a nice big living room. It was only after we moved in that I discovered all the horrible bodges that Captain Silicone (previous owner's father-in-law) had perpetrated. It took me years to sort out his messes.

There were some artificial caves in Newbury, but they weren't for sale. Pity, really. They were pleasantly situated at the edge of Greenham Common and had concrete floors that could easily take a Hardinge (or equivalent) lathe. Big garage doors, too.

[AVGresponding]

https://uxdesign.cc/the-worst-volume-co ... 713dc86950

[tggzzz]

https://uxdesign.cc/the-worst-volume-co ... 713dc86950

Superbly imaginative perversity!

[Zenith]

It reminds me of producing deliberately counter-intuitive computer languages.

https://www.hongkiat.com/blog/bizarre-i ... languages/

Some people would add Forth

https://en.wikipedia.org/wiki/Forth_(pr ... _language)

I always liked it.

[bd139]

https://uxdesign.cc/the-worst-volume-co ... 713dc86950

That isa horrifying but thoroughly enjoyable.

[Zenith]

Given human estate agents choose to ignore even the most basic requirements when you are house hunting, the chances of setting up a "must have a stable temperature" filter is unlikely.

It was bad enough coping with what Sue described to estate agent as my "special needs" (a large living room with decent acoustics). One house we went to was lovely in terms of its condition; its owner had made the conservatory himself and his woodworking was beautiful, as was all his other work around the house; I told him what I thought of his work.

I recall looking at houses with a view to buying years ago. In a few cases there was some horrible piece of DIY the owner was keen to show off. There were one or two hideous cocktail bars. There was an enormous natural stone wall with a gap, dividing and spoiling a nice sized room. There was a rickety stair going up to a loft room, made of the minimum thickness of timber that would do. Reluctantly I climbed it to view the loft room. I felt the stairs flex under my feet and the whole structure creak. I was glad to get down in one piece. They thought these were selling points; I was calculating how much it would cost to have these monstrosities removed, and deducting it from what I was prepared to offer. The conclusion I came to was that there were enough places for sale without these improvements, so I didn't make an offer. I didn't tell them what I thought of their work. I resisted the temptation to burst out laughing. I said these developments were interesting.

[EC8010]

I didn't tell them what I thought of their work. I resisted the temptation to burst out laughing. I said these developments were interesting.

Yes, most peoples' work on their houses is terrible. It was a real pleasure for me to tell this chap that I thought his work was excellent.

I have just been plumbing. SWMBO obeyed complained that the outside tap wouldn't turn off. To cut a long story short, it turned out to be a manufacturing fault common to two taps that had left a sharp burr in the seat to tear the washer. I popped tap in the mill, recut the seat, fitted new washer. Tap now works. Kitchen tap seeped. Careful inspection found a casting blow hole in the seat, corrected by a tiddy bit of Araldite and some careful sanding afterwards. Shoddy original manufacture...

[Zenith]

Yes, most peoples' work on their houses is terrible. It was a real pleasure for me to tell this chap that I thought his work was excellent.

Then there's electrical DIY. I had a great uncle whose electrical installations were - remarkable. In the living room there was a great big 15A socket, which was an extension of a 5A socket, fed by a huge rubber covered cable which ran across a doorway. In the spare bedroom there was a wooden table used for ironing. Attached to one leg there was another great big 15A socket for the iron. That was fed by one of those bayonet plugs which fitted into the 5A light fitting. I'd guess the house was connected to the mains in the 1920s and only had lighting circuits installed. There was no earth for lighting circuits back then.

The best bit is he was a professional electrical engineer. He got an apprenticeship in a power station before WWI and got his qualifications through ICS. That was a recognised way of doing things. Very few people had university engineering degrees in those days. He spent most of his career as chief electrical engineer for a large steel rolling mill. I remember him giving me a lecture on electrical safety. "If you have to touch something you think may be live, stand one legged on a dry mat on your right foot and tap it quickly with the back of your right hand. Electricity doesn't give you a second chance". Sage advice I'm sure, but I've never had to use it. Being a wimp I whip out the multimeter or a test bulb.

I have other horror stories of the same nature.

[EC8010]

Whoops! You have got me onto my pet hobby horse; electrical wiring. Wiring regulations are there to tame injuries and deaths. Wiring regulations are written by panels of IET members who have never wired a house in their life. Wiring regulations are followed religiously by workmen who don't have a clue about Ohm's law or any concept of electrical charge. Does it make sense to have such a large disconnect between the two ends of the spectrum? Then you look at what people do DIY... And you decide that maybe all the restrictions do make sense after all. I had my consumer unit replaced a year ago and the chap who did it said he fully expected to find problems with the house wiring given that it was almost forty years old and that was quite enough time for people to have fiddled with it. He had the good sense not to give me a meaningful look, but he was quite right in thinking that I have added bits, and changed bits. He tested very thoroughly... ...and didn't find anything wrong (phew!). But I had fixed a load of problems I discovered when we moved in.

[Zenith]

I bought a copy of the wiring regulations, the Bible of wiring. It was quite obscure. Much of it was about some sort of water heater where the current passed directly through the water rather than using a heating element. I thought these things were too dangerous for serious consideration. It also went on about the minimum radius of curvature for various cables.

I then bought a book from Smiths for a fiver, which the author said was fully in line with the latest regulations. It explained everything clearly and pointed out several amateur errors to avoid and why. It didn't mention those strange water heaters or minimum radius of curvature for cables.

Now we have Part P of the building regulations. I could never qualify because I'm red-green colour blind. We're getting to the stage where you have to get in a sparky to change a light bulb. Well, unqualified people have been killed messing with light bulbs.

https://en.wikipedia.org/wiki/Claude_Fran%C3%A7ois

My understanding was different; he was in the bath and stood up to adjust the light bulb and received a fatal shock. Darwinism in action.