studiot

Even a pinhole is a gaping chasm for air / microbe mix under pressure. And I don't usually have handy hardened pins for puncturing. The glass and contents do not heat up as quickly as the metal for two reasons. Firstly they both have a much lower heat transfer coefficient than metal soit take longer for the heat to penetrate. Secondly it take more heat to heat up as they both have a higher heat capacity. Any air in the top of the jar will also heat up quite quickly from the metal and so the pressure diferential will be lower. 😄 I never thought of that, when I was younger and stronger. Silly me. +1 But seriously with all these politically rather than scientifically ways of saving the planet - or cynically saving the manufacturers a few coppers - many liquid/semi liwuid products like youghurt used to come in plastic pots, womplete with a replaceable plastic lid over the seal. Nowadays they have dropped the plastic lid ( a very minot % of the total plastic in the packaging. to great inconvenience of customers. We are fast running out of old lids that have been rewashed many times (you can only rewash so many times)

Some manufacturers really seal their jar tops on tightly. So most of my family can't open them. Up to recently I have managed to supply the neccessary brute force, but I am getting older. Once technique I can really recommend is to use a hair drier, on max, bot perhaps 30 second to 1 minute. Play this directly onto the metal top only. the metal wi;; heat up quickly and expand, but the glass will not so voila. The result is a dead easy to open jar.

I'm pleased some find this thread interesting to discuss. A nice change from AI or non-relativity. No I didn't envisage probability being involved, but that is not to say it isn't. If you see a connection please offer it up for discussion. My input is not meant to be prescriptive in any way. Having said that and thinking further about feed forward, we have the possibility of another mechanism. Time delay. It is possible for the error correcting signal to reach the output at the same time at the main process by delaying one or the other appropriately. The effect fro instance on transmission line loudspeakers is dramatic whrn you get that just right. Similarly I remember palying with springline (and later digital) reverb units to explore the audio effects available.

Thinking further about this subject a number of questions occur to me. 1) Does running several kw 24/7 present a fire risk ? 2) Does this constitute commercial use of the land for planning or local tax purposes ? 3) Does this in any way affect the buildings insurance ? 3) If this is now part commercial use, how is capital gains tax affected ? 4) Again if this is now part commercial use does the property have any restrictive covenants against this ? I say this because UK law is heavily restrictive against the ordinary citizen in many respects. For instance if you have a stream/river in your garden as the 'riparian owner' your are generally liable to maintain the banks. But you require a licence to place an electricity generator in the water stream, which is genereally not granted. By contrast in Europe if you want to do this you can actually get a grant towards the cost.

Can you honestly not see that ? 1) There is no capacitor in the curcuit between the ac drive and the transformer primary 2) There is no additional inductance in the form of a motor winding in the secondary circuit of the transformer 3) Neiether the primary nor the secondary circuits are grounded. But you said This circuit shows all 3 changes.

Thank you for wasting my time. I just looked in but I think I will go back to watch the ending of the late night film, whilst you have a nice discussion with the moderator about your attitude.

Well a few numbers might be useful on you psu, don't you think ? As it is not clear whether you are talking about an emitter follower type pass transistor or a collector follower here are a couple of pages to cover either or both eventuality. It would have been much more helpful if you had stated you expected current draw and voltage adjustment range. Since you are using power transistors I assume substantial current draw and therefore you will require all the base drive current to pass through that one (variable) resistor. There are several methods of overcoming this. One is to use a darlington configuration for higher power transistor gain. The other is to add fixed end resistors in seroies with the variable one to ensure that one end of the track is not burnt out. An emitter follower type (circuit 1 in my attachment) is not short circuit proof in respect of the load so again, especially if high powers are envisaged, some protection is best. The collector follower type (circuit 2 in my attachment) is inherently short circuit proof. You should add a high value bleed resistor across your filter/reservoir capacitor. This will discharge a subtantial energy source safely when the supply is switched off. It is unknown what your resources are or if you are using up old stock (if so well done) so further discussion of this would be fine if you have any more questions.

Three members already working hard for you, though you logged straight off after posting and haven't been back since. If this is a serious question, please give some context.

Circuit diagram ?

Well I understood it as one of your better answers.

Doesn't work for me either. It's more basic than that, I can get the drawer open and then close it again but the w10 system insists there is no disk and won't open the drive again. Thanks to SJ for reminding me of that. I remember now finding taking your drive away to be another of the famous 'updates' M$ forces on you even for w10, so going back won't likely cure it either.

It's a long time since I did any work on chip cooling efficiency, but then the raspberyy pi is getting long in the tooth itself. Yes chips will work at 100o +, however the hotter they are the shorter their service life, especially at the high end (It's a non linear degradation curve) I remember that the most efficinet chip cooler were not air cooled but of the 'heatpipe' variety. A suitably volatile liquid is sealed in a tube or pipe directly connected to the chip as metal to case. This carries the heat rapidly away to a secondary heatsink thay will be (possibly force) air cooled, by evaporation and condensation. The cooled liquid then runs back inside the tube to carry on the cycle.

There seem to be a lot of things they haven't told us. Like heat pump suppliers don't tell you you need bigger radiators because they run at lower water temperatures. They may also have super insulated the premises in the article.

Not sure I follow. A UK domestic gas or electricity bill will never be zero due to the standing charge (which is unconscionably high IMHO). Added to which, £40 per month is good for a summer month for someone who doesn't have gas since that powers cooker, fridge, freezer, washing machine, drier, domestic hot water and uncle tom cobbly.

So if we go to 5 watts each, and stick with the 500 that is 2.5 kwatts continuous. That is certainly not enough to heat my home in winter. The BBC article also said that the heat is transferred by an oil.

Here am I wondering if you actually read what i wrote ?

Well I see 1) A sereies capacitor 2) A series motor 3) The system is grounded.

A few thoughts/reservations as the quoted figures sound too good to be true. 500 'computer chips'. I don't know what chips or how much power they draw, but looking at current processor chips say they draw between 0.05 and 0.1 kw each. That is a draw of 25 to 50 kw. So where does this come from ? The average house supply in the UK is 55kw. The average gas boiler puts out between 15kw and 25 kw. But that is intermittent. Presumably these chips are on all the time. And what happens in the summer when home heating is not required ?

Data centre in the shed reduces energy bills to £40 Terrence Bridges says he "can't fault the heating system", which captures heat from more than 500 mini-computers processing data ByBen Schofield BBC East, political correspondent Published 16 November 2025, 03:10 GMT Updated 7 hours ago An Essex couple have become the first people in the country to trial a scheme that sees them heat their home using a data centre in their garden shed. Terrence and Lesley Bridges have seen their energy bills drop dramatically, from £375 a month down to as low as £40, since they swapped their gas boiler for a HeatHub – a small data centre containing more than 500 computers. https://www.bbc.co.uk/news/articles/c0rpy7envr5o Interesting approach.

Softly Softly please. I am hoping that Tonia is a real human being and that "dear colleagues" is only an excruciation of a translator. I stand firmly by my bridge example. I could have chosen all sorts of examples say a garden or a stand that the Chelsea Flower Show. Or I could have quoted Brouwer "All architects should actually be designing a chair".

Welcome Tonia and thank you for an interesting topic. Not sure which side of this divide you are coming from but the subject fits nicely into my observation that our consideration processes can be divided into two camps (though there is obviouly overlap as well as each can be used to support the other). I call these Analysis and Synthesis. Analysis is the study of something that is already there. This may involve measurement, observation, comparison, description, recording. Synthesis is the production of something that is not already there. I hold that synthesis is actually the more difficult of the two. For instance it is one thing to take photographs, measurements and so on of a bridge across a valley, and analyse how strong it is. It is quite a different matter to look at an empty valley and buiild a bridge across it, that can carry say a railway train. The Romans built multi-tier multi-arch viaducts. It is instructive to find out how they knew where to start the base of the arches so that when the got to the top and the edges it would all end up in the right place and fit together. Take care how you respond in your first 24 hours as you only have 5 posts available. After that you can post at will.

I have a Dell with that problem but it has Windows 10. M$ said it could not be upgraded to Windows 11, when that came out despite their blandishments to the contrary. ~W10 and 11 are also a pain in the arse for other devices M$ would like to forget, like scanners and so on.

Not sure why time crystals imply other types of mass ? Examples of what I was thinking of are Stokes' bubbles, electron and hole mobilities in ordinary crystals, the anomalous Hall effect.

What about negative mass and effective mass ?

Yes you do need a mathematician. I can see at least 2 changes. Can you spot a third ?