gubby

Joined 12 years ago

Karma
232
Submissions
66
Member since
Jul 31
London programmer.
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Recent submissions

Comment · 3 years ago
Interesting idea, I suspect it isn't possible with the existing connector. You either need to increase the voltage or the current.

The new 240W spec is 5A and 50V. Assuming 5A is the thermal limit of the connector and that can't change, to get 1500W you'd need 300V, which is probably higher than the connector can support in terms of conductor spacing.

Comment · 3 years ago
> There's not a single smart plug on market that won't connect to cloud to control plug from anywhere

Look at Shelly devices, they are exactly what you are looking for (in no way affiliated)

Comment · 3 years ago
Interesting point, but of course it’s not possible to create a platform with an average win rate of 80%.
Comment · 4 years ago
Grounding isn't really about dispersing energy over an area, it's about creating a situation where faults can be detected and circuits automatically opened to prevent shocks or fires. It actually gets very involved to reason through the exact purpose of ground connections when you start considering all the different types and combinations of faults (indoors, outdoors, person in contact with true earth, person touching exposed metal pipe, etc etc).
Comment · 4 years ago
Very often with contract law there is mostly no such thing as 'knowing a claim is not legally valid'. A lot of contract law is established by precedent, meaning in those cases nobody including the judge knew the enforceability of the issue before the judgement was written. Cases are also rarely identical examples of previous cases, meaning there can be an element of precedent setting even in cases that seem routine.
Comment · 4 years ago
I suspect (IANAL) that in a sense, it already is, in that anybody testing this in court would deny the existence of any form of contract acceptance, and that would be the end of it.
Comment · 4 years ago
And that heat ends up at the worst possible place, on the junction itself, meaning the device has to also work to remove it.
Comment · 4 years ago
For an article about a specific scientific concept (the proportional land use for different types of generator), it’s surprising they actually got that concept wrong in all their examples:

“These can have a small land footprint of just 8m2 per MWh”

This is implies that the land is being consumed by the generator. I assume there is an implied “per year” or “per day” but it’s a little sloppy.

Comment · 4 years ago
They look identical to me too, but I know that I can perceive RGB hues.
Comment · 4 years ago
This has been true of OSX, especially since around 10.15. The performance degradation of the upgrade to 10.15 from 10.14 was so immediate and severe that I reverted it.
Comment · 4 years ago
It only had itself to blame
Comment · 4 years ago
And the atrocious disregard for performance over the last few years. My 2014 OSX 10.14 home Mac Mini is so much faster and more responsive than my 2021 OSX 12.4 work Mac mini (with no notable difference in features) it is difficult to conclude anything other than malice.
Comment · 4 years ago
For some types of power supply, not having a proper ground can dangerous for reasons many people don’t realise. It’s not just about fault currents ‘flowing to ground’. Should just the supply neutral become disconnected, such as during high wind, then without a proper ground setup every metal item in your house that is grounded (such as microwave cases) can become live. It depends on how things are configured, but this type of lethal fault is a real possibility if neutral and ground are bonded at your house as they often are.

In the case where your power is derived from another property as you describe, in the UK we would normally call this a ‘TT’ power supply which you can google. It is absolutely essential (life and death) to have both a good grounding rod and an RCD at your end.

A others have said, get an electrician who understands the subtleties of outbuilding power supplies. If you cannot do that for whatever reason, I suggest first reading up extensively on the different kinds of earthing system, and finding out which one you effectively have.

Since you had no ground previously, it is likely that just live and neutral have been exported from your neighbours property (TT). You can probably check this by visual inspection, and it isn’t actually a problem provided you fix the grounding and protection at your end. To fix this grounding problem what happened? Did the electrician install a grounding rod? Did they happen to measure the impedance of it and write that somewhere? Do you have an RCD in your consumer unit (fuse box)?

Comment · 4 years ago
Comment · 4 years ago
In response to the comments of the form "just install PTZ cameras", I have done an installation like this for a modest-sized site, and it is extremely difficult and time consuming (+ expensive) to install enough cameras to cover the site if you want any chance of actually recognising a face or a numberplate. If all you want to know is: "blob detected at rear gate", it's of course a lot easier, but then you might as well use a PIR sensor.

The problem is mapping a 3D space, where a 'perp' can often face in any direction, onto a series of 2D planes. PTZ cameras only help if they are meticulously programmed to track movement or respond to motion events from other sources, or you have a skilled operator 24x7.

It's even harder if the system needs to work well at night, since it requires either IR or visible light illumination.

I don't know how well this drone+sensors setup would work, but can definitely imagine there is a subset of the market where this would be better than fixed cameras, perhaps a large property where there are multiple entrances and exits, and lots of potential targets. e.g. a farm, where there are long easily traversed boundaries between the property and neighbouring properties.

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