Skip Navigation

InitialsDiceBearhttps://github.com/dicebear/dicebearhttps://creativecommons.org/publicdomain/zero/1.0/„Initials” (https://github.com/dicebear/dicebear) by „DiceBear”, licensed under „CC0 1.0” (https://creativecommons.org/publicdomain/zero/1.0/)WA
Posts
24
Comments
339
Joined
2 yr. ago

  • In the picture are 3 coiled wires, all sharing the same dark grey ring/toroid (but it looks yellow because it is wrapped in yellow kapton tape).

    If you try and send the same signal through each of these 3 wires then they will all fight and cancel each other out (a bit like 3 people trying to through the same narrow doorway at the exact same time; no-one gets through). If the signals are different on each wire then they will get through fine (a bit like people going through a door at different times).

    common mode chokes = choke/kill the signals that are common/same on all wires

    You typically do not want common mode signals to exit your device and travel along cables, because then these cables act like radio transmitters. The exact reasoning for that is a bit more than I want to write here, but it's best explained with some pictures and phrases like "you turned your cable into a monopole you doof, use more common mode chokes and think of England".

    Internally these devices work using magnetic fields in the dark-grey (ferrite) ring. I'm more familiar with 2-wire chokes where the coils are wound in opposite directions (so the magnetic fields they make cancel out), I am not sure how it works for 3 windings.

  • Microchannel coils: Wow. I assumed the pressures were too high for such construction to succeed. Thankyou :)

    Fluid metering: I was aware of TXVs and capillary tubes, but not reverse bypass piston inserts. Would these options only be a few dollars difference in BOM price between each other? I guess the extra labour from soldering more pipes and connections for a TXV might be more costly than the extra materials themselves.

    A vs N folded coils: interesting. I have mostly seen split systems and their unfolded coils, not central AC units with these A & N folded coils.

  • heat pumps instead of traditional compressor based ac systems

    Heat pumps are compressor based systems. They are the same technology.

    In addition to advances in fin design and compressor and motor efficiency and materials

    This reads lot like an answer from an LLM. Did you use one? My apologies if not, but you sound very suspicious.

  • Definitely. Absolute scams. They deserve the "0 energy stars" ratings I've seen printed on their boxes.

    My family bought one of those for one of my grandparents. On a 35degC day it was only able to cool the room by a few degrees and it was still humid inside.

    Converting them into dual-hose systems would be so simple (almost free) to the manufacturer, but instead they rely on deceiving buyers with a promise of something that is not delivered.

  • :(

    They really don't put much plastic in these things.

    I hope for a world where little phone competitors are more viable, then we might see some actually caring about bits like this. There are a few but they're expensive and I balk at the cost of new phones anyway (I use second hand ones off eBay).

  • As a general rule I hold suspicion to any marketing that claims that using CO2 (or other products of burning) is environmental friendly. The products you get from burning fuels are supposed to be useless and of low value, otherwise they are not burning them efficiently.

    To turn CO2 into potassium carbonate (pearl ash) you will need a lot of energy. Where they get this energy from is far more important than where they got the CO2 from. I would not be surprised if it is more environmentally friendly to make the pearl ash through a different process and ignore the CO2 rather than trying to convert the CO2 into pearl ash.

    Background chemistry

    Fuels are chemicals with a lot of potential chemical energy stored in them. They are generally considered (at a minimum) flammable or "reactive" in some way.

    When we burn fuels we turn them into products with very little potential chemical energy, mainly CO2. You cannot burn CO2 and get energy out of it, it is a "stable" or "unreactive" chemical. It has very little chemical energy stored in it compared to the original fuel.

    The difference in stored chemical energy between the fuel (eg methane CH4) and the products (eg CO2) is turned into heat and then electricity (via steam turbines). If your products are still reactive then you have not used them to their full potential and you will not get as much heat out as you could (not to mention improperly burned products tend to be toxic, eg carbon monoxide).

    Now let's look at potassium carbonate (K2CO3). It's a somewhat reactive chemical, it's not anywhere as stable as CO2, you can observe this by the fact it readily wants to react with other chemicals (caveman test: put it on your skin and it will sting). CO2 is very stable and does not want to do much (caveman test: put it on your skin and you won't feel it).

    To make K2CO3 from CO2 you will require energy input. Turning an unreactive chemical into a reactive one is a bit like the reverse of burning something. This energy will probably come from burning more coal or gas. I suspect it will require more coal/gas than making the CO2 did, so net overall you will probably be releasing more CO2 than you capture and turn into K2CO3.

    Of course if they're using renewal energy (solar) for this step then this could be a net positive.

    My level of trust in the honesty of product packaging and marketing is pretty low and if they don't mention it then they obviously don't think it's important. 🤷

    EDIT: I'll also add that "carbon capture" projects (things that claim to get rid of or make use of the CO2 from burning fuels) are universally disasters or scams.

    EDIT2: I've taking some simplification liberties with the chemistry here. Technically CO2 isn't completely stable, you can do stuff like make weak acids in water with it, but I do not believe anyone has found a way for that to usefully use up what we emit from burning fuels.

  • All of the the surface normals are backwards. This means your shoe is inside-out; instead of being a solid shoe in a vacuum it's a shoe-shaped-hole inside a solid universe.

    By default blender renders all polys as double-sided so you mostly don't notice (other than some lighting oddities near corners). Turn on backface culling if you want to check if your normals are the right way around or not.

    I often end up with some of my polys backwards because of the way I extrude and join parts of my models. I distinctly remember a bug in Gmax (old free version of 3DSmax) where the mirror tool would create polygons with some special, broken property where their normals would be correct in the editor, but completely wrong when exported :( much time and hassle was lost to that.

  • !?!?! Aussie.zone says this was posted "12 hours ago", how did I miss this major development all day?

    Oh. -_-

    Would it be possible to edit this article to point to the archive.org link, then create a new post for the new news? Not sure if you want to at this point, you're probably sick of this roundabout. Thankyou for sharing it all.

  • it would be interesting to know if the hole is connected right through to the barb or not

    I feel very uncomfortable with the thought of probing this thing with long metal rods whilst looking down the end.

    maybe hint it to police

    I guess I could try and send them the pics and ask them about this "suspicious object". Hopefully it's just a bong.

    (I can't quite see it being an arsenic cannon, but yeah I wasn't planning on trusting my copper oxide assumption regardless xD)

  • I was going to reply with "you can't use barbed fittings at high pressures", but I looked it up and found some claiming 150psi (10 atmospheres). Huh. Perhaps this did start life as a hydraulic cylinder that has had some parts lopped off.

    Not sure what the tube is filled with, but it looks like a lot of corrosion.

    I don't think it's built up corrosion. The pipe is steel and corrodes to red/brown iron oxide, as visible around the circumference at the end. The green colour in the filling is not an iron oxide. It might be a copper oxide, or some dye in the white material.

  • Hmm. I admittedly don't have experience here, but I guess that makes sense.

    I'm not sure how you would attach an elbow to a barb fitting though. A rubber pipe is usually used on these (but that would then burn/melt).

    Is plaster of paris usually used to make bongs? I've only really noticed plastic bottle ones in the bush. I guess plaster will survive burning things better than plastic, but it's also porous.

  • Anything odd with temperatures or power draws perhaps? nv-top shows both for me (but I run an AMD GPU + non-proprietary drivers), otherwise lm-sensors might be good.

    nvtop seems to show normal usage

    Neither the GPU nor CPU utilisation change at the 30 min mark? If one is pegged at 100% then it's probably hard to work out what is going on. Running a singleplayer game staring at a wall and configured with limited framrate might let you run both the CPU and GPU at less than 100%, perhaps making it easier to see if one or the other suddenly changes.

  • The rough (frit) glaze surface would be the opposite of what you want in a HV bushing, because they would wick and store conductive water.

    Interestingly it's on the both the top and the bottom. Perhaps this high surface area makes it more compatible with some specific glues; allowing you to stack a pile of these pieces together to make a full bushing? That might also explain why there is not hole in the middle, this could be a compression style bushing stack for holding wires up in the air off a surface.

  • Have not seen this mentioned anywhere else so I'll add: this is a "board edge connector". A whole PCB will plug into this socket, rather than a plastic connector on the end of some wires.

    Picture plugging a graphics card into a socket on a motherboard. It's that type of connector. The PCB it will plug into will have exposed metal pads on a bit that juts out.

  • Probably double-sided prototyping PCBs. The double-sided ones tend to be green (FR4 fiberglass resin), the single-sided orange (FR2 paper phenolic-resin).

    Terminology varies, a lot of greymarket sellers use "veroboard", "prototype board" and "breadboard" interchangeably.

    The glue between the copper pads and the board itself tend to better with the double-sided boards, I agree with you OP :) Although this isn't universal, I've had some nasty bare copper boards on FR4 where the pads pop off when you try to solder to them; and some old FR2 boards with really well adhered pads. I've read somewhere that this might (?) be due to moisture in the PCB boiling off when you put the soldering iron to a pad and that baking the board in an oven first can help, but I have not tried that. I suspect a lot of it comes down to the quality of adhesive used between copper and substrate.

  • There are no changes to the nbn wholesale pricing of these speed tiers arising from the speed increases.

    Interesting, but how will this affect the price for end users? There are other fees charged to the ISPs too?

    I am suspicious because NBNco only mentions wholesale pricing in this article, not end user pricing. They would have modelled it and then chosen not to talk about it. They might not technically be the entity finally billing you, but they're responsible for strong and direct impacts on what users pay.