commercial appliances didn’t take any stand-by measures to avoid “keeping the wires warm”

Generally speaking, the amount of standby current attributable to the capacitors has historically paled in comparison to the much higher standby current of the active electronics therein. The One Watt Initiative is one such program that shed light on “vampire draw” and posed a tangible target for what standby power draw for an appliance should look like: 1 Watt.

A rather infamous example of profligate standby power was TV set-top boxes, rented from the satellite or cable TV company, at some 35 Watts. Because these weren’t owned by customers, so-called free-market principles couldn’t apply and consumers couldn’t “vote with their feet” for less power-hungry set-top boxes. And the satellite/cable TV companies didn’t care, since they weren’t the ones paying for the electricity to keep those boxes powered. Hence, a perverse scenario where power was being actively wasted.

It took both carrots (eg EnergyStar labels) and sticks (eg EU and California legislation) to make changes to this sordid situation. But to answer your question in the modern day, where standby current mostly is now kept around 1 Watt or lower, it all boils down to design tradeoffs.

For most consumer products, a physical power-switch has gone the way of the dodo. The demand is for products which can turn “off” but can start up again at a moment’s notice. Excellent electronics design could achieve low-power consumption in the milliwatts, but this often entails an entirely separate circuit and supply which is used to wake up the main circuit of the appliance. That’s extra parts and thus more that can go wrong and cause warranty claims. This is really only pursued if power consumption is paramount, such as for battery-powered devices. And even with all that effort, the power draw will never be zero.

So instead, the more common approach is to reuse the existing supply and circuitry, but try to optimize it when not in active operation. That means accepting that the power supply circuitry will have some amount of always-on draw, and that the total appliance will have a standby power draw which is deemed acceptable.

I would also be remiss if I didn’t mention the EU Directives since 2013 which mandate particular power-factor targets, which for most non-motor appliances can only be achieved with active components, ie Active Power Factor Correction (Active PFC). While not strictly addressing standby power, this would be an example of a measure undertaken to avoid the heating caused by apparent power, both locally and through the grid.

How were you measuring the current in the power cable? Is this with a Kill-o-watt device or perhaps with a clamp meter and a line splitter?

As for why there is a capacitor across the mains input, a switching DC power supply like an ATX PSU draws current in a fairly jagged fashion. So to stabilize the input voltage, as well as preventing the switching noise from propagating through the mains and radiating everywhere, some capacitors are placed across the AC lines. This is a large oversimplification, though, as the type and values of these capacitors are the subject of careful design.

Since a capacitor charges and discharges based on the voltage across it, and because AC power changes voltage “polarity” at 50 or 60 Hz, the flow of charge into and out of the capacitor will be measurable as a small current.

Your choice of measuring instrument will affect how precisely you can measure this apparent power, which will in-turn affect how your instrument reports the power factor. It can also be that the current in question also includes some of the standby current for keeping the PSU’s logic ICs in a ready state, for when the computer starts up. So that would also explain why the power factor isn’t exactly zero.

Agreed, it’s a very bad design. If your school speed limit covers most of the daylight hours on weekdays, is the implicit suggestion that it’s fine to drive faster on weekends and during nighttime? The street should be rebuilt to enforce the desired speed limits, not with paint or signs.

Oh, we’re talking about the letters on the glass. My bad lol

I know this is c/programmerhumor but I’ll take a stab at the question. If I may broaden the question to include collectively the set of software engineers, programmers, and (from a mainframe era) operators – but will still use “programmers” for brevity – then we can find examples of all sorts of other roles being taken over by computers or subsumed as part of a different worker’s job description. So it shouldn’t really be surprising that the job of programmer would also be partially offloaded.

The classic example of computer-induced obsolescence is the job of typist, where a large organization would employ staff to operate typewriters to convert hand-written memos into typed documents. Helped by the availability of word processors – no, not the software but a standalone appliance – and then the personal computer, the expectation moved to where knowledge workers have to type their own documents.

If we look to some of the earliest analog computers, built to compute differential equations such as for weather and flow analysis, a small team of people would be needed to operate and interpret the results for the research staff. But nowadays, researchers are expected to crunch their own numbers, possibly aided by a statistics or data analyst expert, but they’re still working in R or Python, as opposed to a dedicated person or team that sets up the analysis program.

In that sense, the job of setting up tasks to run on a computer – that is, the old definition of “programming” the machine – has moved to the users. But alleviating the burden on programmers isn’t always going to be viewed as obsolescence. Otherwise, we’d say that tab-complete is making human-typing obsolete lol

Is it a requirement that the Windows box needs to be able to interact with the serial stream to/from the PLC and instrument? If it only needs to monitor the serial connection, would it suffice to just have Windows “tap” the RS232 lines to receive the signal but otherwise let it continue, and never TX onto the lines?

If you’re looking to do this project without a microcontroller – it’s an exercise that every SW engineer should consider doing at least once – then the venerable 555 timer may be of aid here:

https://elonics.org/light-sensor-circuit-using-ldr-555-timer-adjustable/

The perspective is entirely accidental lol. I just wanted to photograph it from the sides which have the fewest blemishes. I do see now why it might look like it’s 2 meters tall.

In future, I’ll add a banana for scale haha

If there were changes in 2020 to 2024 inclusive, then yes, I’d write it as 2020-2024. But if not inclusive, then I’d write 2021-2023.

I’m not any type of lawyer, especially not a copyright lawyer, though I’ve been informed that the point of having the copyright date is to mark when the work (book, website, photo, etc) was produced and when last edited. Both aspects are important, since the original date is when the copyright clock starts counting, and having it further in the past is useful to prove infringement that occurs later.

Likewise, each update to the work imbues a new copyright on just the updated parts, which starts its own clock, and is again useful to prosecute infringement.

As a result, updating the copyright date is not an exercise of writing today’s year. But rather, it’s adding years to a list, compressing as needed, but never removing any years. For example, if a work was created in 2012 and updated in 2013, 2015, 2016, 2017, and 2022, the copyright date could look like:

© 2012, 2013, 2015-2017, 2022

To be clear, I’m not terribly concerned with whether large, institutional copyright holders are able to effectively litigate their IP holdings. Rather, this is advice for small producers of works, like freelancers or folks hosting their own blog. In the age of AI, copyright abuse against small players is now rampant, and a copyright date that is always the current year is ammunition for an AI company’s lawyer to argue that they didn’t plagiarize your work, because your work has a date that came after when they trained their models.

Not that the copyright date is wholly dispositive, but it makes clear from the get-go when a work came unto copyright protection.

It would be amazing if PCIe lanes becomes the predominant limiting factor, rather than drive cost, for building large storage arrays. What a world it would be, when even Epyc and its lanes-for-days proves to be insufficient for large Chia miners err Plex servers uh, Linux ISO mirrors.

This isn’t quite an ELI5, but ARRL has a 2004 article on FM fundamentals; it’s five pages intended for a beginner ham radio operator, but applicable to all FM applications nevertheless. It also discusses four different ways to receive FM.

But to answer your question directly:

The frequency of the FM signal at any instant in time is called the instantaneous frequency. The variations back and forth around the carrier frequency are known as deviation

FM can also be detected by a PLL. As shown in Figure 6, the PLL’s natural function of tracking a changing input frequency can be employed to generate a voltage that varies as the input frequency change

In a nutshell, FM only ever has one instantaneous frequency at a time, which dances around the nominal center frequency (aka carrier). So the receiver has to detect the instantaneous frequency, relative to the carrier.

To actually recover the original signal, the receiver must also account for the modulation index used by the transmitter, which describes how much the output will deviate for a given input frequency. The modulation index is usually standardized for the application, such as FM broadcasting, amateur radio FM, walkie talkie FM, etc.

Because a larger modulation index means the same input signal will result in wider deviations, more RF bandwidth is used, spreading the signal wider and generally improving noise immunity.

Point taken. I’ve edited the title to include both measurements in inches.

It’s the curse of being engineering-minded in the USA. Much of homegym stuff here is in US customary units, but competition-inspired weightlifting equipment and anything engineering-related is in metric/SI.

Best I can do is to start with the original units (for search engine indexing), provide the conversion for people using the opposing unit system, and then try to do my work consistently within just one unit system.

When it comes to what insurance does or doesn’t cover, the best answer will come from the text of the policy itself. This is, unfortunately, very dry reading and most people – although instructed to keep a copy handy – don’t have the full text nearby. That said, because of the regulated nature of insurance in the USA, standardized forms of policies exist, and homeowner policies are no exception.

The common homeowner policies are numbered HO-1 to HO-8. HO-1 only pays out only for the ten listened “perils”, and is thus the most barren policy available. Not all HO-1 policies are verbatim identical, but the gist usually matches.

We can look at this sample text from a random HO-1 (issued by American Family Insurance). Page 5 shows that “fire or lightning” is covered, so that’s a good start.

On page 6, we find the exceptions to the coverage, so if any of these apply, the policy will not pay out. Nothing in Part A would seem to apply to a DIY LED project, unless you tell me your LEDs are radioactive. Part B also doesn’t apply, unless you’re somehow perpetuating a fraud using LEDs.

Part C reads like it could apply, because it mentions “construction”, “design, workmanship or specification”, and “maintenance”, but this section only applies to the dwelling and so refers to those things which are permanently affixed to the house. That would include things like ceiling fans and light fixtures, but wouldn’t include stuff that is attached to the walls using thumbtacks or 3M Command strips. It even says that:

However, we do cover any resulting loss to property described in Coverage A - Dwelling and Dwelling Extension not excluded or excepted in this policy.

This clause basically means the exceptions on Page 6 should be interpreted narrowly, not broadly.

The point is, in the entire policy, there isn’t a clause that requires listed equipment, and remember that this is the most bare bones policy commonly available. If such a requirement did exist, then building your own PC wouldn’t be possible, since the standards bodies do not test individual computer parts – except the PSU, because that plugs into the mains.

If a fire that damages the house does occur, the most probable causes would be due to: 1) an unlisted power supply or power brick feeding the ESP32 or the LEDs, or 2) no current limiting (eg a fuse) to cut out the power supply. Other failures like a shorted LED are unlikely to actually cause a house fire, and the insurance companies and UL know this; they’re more focused on preventing arc-faults that contribute to an estimated 50% of electrical house fires every year.

Good design and clean installation on your part, and using properly listed low-voltage power supplies, will mitigate the major fire risks, leaving just software bugs and lighting snafus for you to deal with.

As a matter of completeness, if there is an unlikely fire, be it from an LED project or from a candle falling over, the insurance company will still pay. But big or small, the claim will be recorded in the CLUE database along with the payout amount. This often reflects negatively on homeowners, so future rate increases may occur. But that varies by state. In any case, though, the insurance policy has still done its job: cover a non-intentional loss.

I would nevertheless advise you to have a look at what sort of homeowner policy your dwelling is covered under. Everything beyond HO-1 is nicer, and some even include limited claim forgiveness of some kind (for a price). Also consider talking to your insurance agent, who should be able to help interpret how the policy applies.

My first thought for a compact, air-blower would be the inflater for air mattresses. They’re already fairly small, have a high flow rate, and exist in forms which accept 12 VDC.

Another option is a small tank of compressed air, but that option is either heavy (steel tank) or stores air at inefficient, low pressures (plastic tank).

I suppose a third option is to rig a can of air-duster so that it blows through the whistle. That would be mechanically simple to implement a solenoid to press the valve, although there is a small environmental cost to using cans of air-duster regularly.

The 74AHCT125N appears to be a 3v to 5v level shifter, which I wouldn’t expect to be drawing a lot of current. So if just the adapter’s presence is causing 0.2v drop, then yeah, that would suggest the output current of the port’s voltage rail isn’t very high, causing substantial sag.

To be abundantly clear, is the Blueretro meant to work when only powered by the console? It certainly wouldn’t be as convenient – an extra cable and power block to deal with – but everything is functional when externally powered by USB, yes?

Do I understand that your original post is debugging why the console isn’t sufficient to power the Blueretro?

I don’t have specific experience with game consoles, but the erratic behavior when powered by the console suggests that the port’s voltage is sagging when the Blueretro is attached, possibly lower than what the AMS1117 can tolerate.

A quick search seems to show that the AMS1117 has a minimum dropout voltage of 1v. So for 3.3v output, the input must not drop below 4.3v. Other Low Dropout (LDO) regulators could have a smaller dropout voltage, but that might not be the root-cause.

It’s possible that without load, the port provides 4.6-5v. But when loaded, it dips below 4.3v, producing the behavior you see. The problem then becomes: is it the NES that’s not providing sufficient current on the voltage bus, or is it the Blueretro trying to draw too much current?

Are you able to measure the port’s voltage bus when the Blueretro is attached? That would help prove if the bus is sagging. Does the Blueretro allow you to use USB power when plugged into the console?

I think a price can absolutely be affixed to the half afternoon I spent to drill eight of these plates to my satisfaction. And at some point, it’d be easier to buy high-quality metric plates from the start (at double the price).

But what’s priceless is turning a daydream into reality, after some rough sketches and not finding anyone else that’s done the same. These are also sort-of a talking piece when I show off my homegym during house parties.

Yeah, my whole homegym is a strange mix of equipment melded with DIY stuff I’ve put together to meet my – admittedly particular – needs. I expect that hole saw to also be useful when I start making accessories out of metal, which will be a new frontier for me.

At least on my machine, that link doesn’t work unless I explicitly change it to HTTP (no S).