Talk:2818: Circuit Symbols

The direct link to the comic is getting a 404 error. But it appears at the xkcd.com home page. Barmar (talk) 01:31, 22 August 2023 (UTC)

The link is working now. Nitpicking (talk) 02:33, 22 August 2023 (UTC)

Randall is symbolizing sheep with a coil because ... wool takes a helical shape. See https://commons.wikimedia.org/wiki/Wool#/media/File:Royal_Winter_Fair_Wool.jpg. Nitpicking (talk) 02:33, 22 August 2023 (UTC)

I think it's meant to be a little prince reference; it's a "box with three holes" 172.71.222.76 06:07, 11 December 2023 (UTC)

The title text is probably a reference to the classic novella "The Scarlet Letter" by Nathaniel Hawthorne (a common classroom reading in the US). In this novella, a young Puritan woman "sins" by having a child out of wedlock. She is punished by having to wear the letter A (for adultery). Comsmomf (talk) 02:54, 22 August 2023 (UTC)

Can someone with more wiki-foo than me please put the actual images for the symbols in a new first column? Blackbearnh (talk) 03:01, 22 August 2023 (UTC)

The easy way to do this might be with the SpriteSheet extension, but maybe that's more trouble than it's worth. Any admin thoughts about installing it? JohnHawkinson (talk) 02:22, 25 August 2023 (UTC)

I tried, unsuccessfully, to learn if there were "Scarlet Letters" that represented other sins ['A' is mentioned to be for 'Adultery', Maybe 'O' for Onanism?] These Are Not The Comments You Are Looking For (talk) 03:41, 22 August 2023 (UTC)

From what I understand, ‘BJ’ had its fair share of supporters. 172.70.210.247 04:47, 22 August 2023 (UTC)

What exactly does "the opposite of capacitors" mean in this context? I'm not that familiar with EE, but from my limited understanding of inductors this is an incorrect and confusing statement. 172.70.126.79 08:07, 22 August 2023 (UTC)

They are the conjugate complex (so the sentence is kind of half-true), if you consider complex impedances. Sebastian --172.68.110.169 08:56, 22 August 2023 (UTC)

Behaviorally the description makes sense, capacitors behave the same way regarding voltage vs. current as inductors behave regarding current vs. voltage and vice versa. Capacitors can "instantaneously" allow a spike in the current flowing through the circuit path that they are placed in, while the voltage across a capacitor can't change instantaneously and requires time to change incrementally (with a corresponding decline over time in the current flowing). Inductors "instantaneously" allow the voltage across their terminals to spike, but the current flowing through it can't change instantaneously and requires time to change incrementally (with a corresponding decline in the voltage across the inductor). Capacitors can act as a sort of "shock absorber" (no pun intended) or low-pass frequency filter for voltages, as inductors can for current. So they are very much considered complementary and the "essentially the opposite of capacitors" comment does pretty much make sense to EEs. But yes, it's not a particularly illuminating description without that background, and the description isn't really valid regarding their physical makeup or what makes them tick, just their role in a circuit. 172.71.146.213 09:32, 22 August 2023 (UTC)

Incapacitors 172.70.85.108 16:48, 25 August 2023 (UTC)

The "overpass" is troubling me, as a map fan. Dependant upon the conventions of any given map illustrator this could easily be more an underpass (main road being the || track, lesser track being the — that sneaks beneath it) or a 'green bridge' (road is the — and the bridge 'symbol' is the || with no actual route using the space between its edges) or a minor road intersection of an uncrossable dual carriageway (each || is a directional way, separated by central reservation, and a historic road/lane is given T-junction access to/from the adjacent direction of travel, but no local flyover to access the opposite continuation/direction, probably have to use other flyovers/turning points above and below this snapshot). Or it's just a regular major/minor crossroads (track-level horizontal/E-W, more main road vertically/N-S) and is entirely at-grade so not involving a bridge at all. But all very much will rely upon the publisher's/renderer's choice of map-symbolism. 172.70.91.95 11:27, 22 August 2023 (UTC)

What's your hope? That Randall will edit his comic? -- Dtgriscom (talk) 11:41, 22 August 2023 (UTC)

No more than I wish he'd use IEC resistors rather than the US zigzags. Just highlighting that (in isolation) there's so easily an alternate inference, dependent upon what notation/symbology you're most exposed to. 172.70.162.199 16:36, 22 August 2023 (UTC)

I appreciated the map trivia, personally Dextrous Fred (talk) 15:18, 22 August 2023 (UTC)

Cheers, though I can't help but think that I explained it badly. And without much reason to. 172.70.162.199 16:36, 22 August 2023 (UTC)

I added the joke about needing a citation-needed joke. Please remove if you don't feel it was needed after all.

Where I live the distinction between underpass and overpass is more about whether the bridge is at grade, and excavation has been done for the other road to pass under (i.e. under the ground level) or the bridge is above grade and the road it crosses over is at grade. --162.158.63.159 11:28, 25 August 2023 (UTC)

From my perspective, you also need to consider flyovers (bridges rising above grade, usually more minor or singular carriageways compared to the at-grade main road with or without median-separated carriageways). If the main route rises over the minor (which remains at-grade, more or less) with clear over-ground construction, it's just a road-bridge. An underpass need not be subterrainean, and often can be an at-grade "original" route (typically pedestrian) beneath the embankmented new major road (or other route, e.g. rail) that was engineered across it, in the same subtle manner as a culvert. Or even what you'd now term the stretch of road "bridged" (or tunnelled) beneath the building of a cross-highway shopping centre, like some towns do in order to sustain an inner ringroad and a large footprint shopping centre.

In general, if the 'over' road doesn't really notice the 'under' (it's still mostly the same grass verging, maybe briefly slightly higher crash-barriers on top of whatever embankment-guarding barriers already exist but no clear 'bridge' details) then I'd just name the underpass as such, as everything on that is definitely going to know that it is diving under the upper route

It can be complicated. The extended runway seen here is possibly at-grade overpass, w.r.t the whole airport "level" (equivalent to a by-pass embankment?), while the road looks sunken (as can be seen by how much the pedestrian side-portal need not be). It could be a runway on an overpass, though I'd say the road is an underpass (with a possible argument that it was always a cut'n'cover tunnel, or passing under really long bridge). 172.70.90.138 17:46, 25 August 2023 (UTC)

With a capacitor you can build a low-pass filter. It can be used in signal processing like audio devices to filter out noise. 172.70.243.218 21:01, 22 August 2023 (UTC)

I think the Battery/Baettry/Batttttttttery joke is probably a reference to the oreo/oreoreo/etc meme that can be seen at https://i.kym-cdn.com/photos/images/original/001/839/727/d7f.jpg . 172.70.38.170 13:58, 23 August 2023 (UTC)Bumpf

Feel free to add that to the page! --FaviFake (talk) 20:44, 23 August 2023 (UTC)

To me the last one sounds like hoe Metallica sings battery in the song ‘Battery’

The electricity in a wave pool citation needed is the first properly funny one I've seen in quite a while - I approve. 172.70.85.135 16:49, 25 August 2023 (UTC)

The capacitor explanation is a bit of a mess at the moment, with pronouns lacking any apparent referent. I'm going to clean it up to the best of my ability, but since I only know things from the civil engineering side and not the electrical engineering side, it will almost certainly need someone who actually understands capacitors to give it a once or twice over.162.158.174.197 15:55, 29 August 2023 (UTC)