tag:blogger.com,1999:blog-10000144.post1988813925808084888..comments2024-03-13T09:47:40.487+00:00Comments on Cockpit Conversation: Hats Not CatsAviatrixhttp://www.blogger.com/profile/13634111275860140084noreply@blogger.comBlogger20125tag:blogger.com,1999:blog-10000144.post-62839761884784077642011-05-23T15:34:56.052+00:002011-05-23T15:34:56.052+00:00HMMM.- Every alternator I've come across so fa...HMMM.- Every alternator I've come across so far, has sufficient residual magnetism to produce a self-excitation of the field...once ths starts generating,the regulator should allow the battery in-circuit.<br /><br /> A slight diversion on what's already been stated- Stators are wound to give 3-phase output. Usual failure-mode is a phase going down due to a failed winding or diode-set. You'll still get a reduced output at reduced voltage, probably enough to run the basics needed to get you down safely.cockney stevenoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-58654475154923831292011-05-22T22:23:19.460+00:002011-05-22T22:23:19.460+00:00The need to know aspects of generators versus alte...The need to know aspects of generators versus alternators are that <br /><br />* if the battery is dead and I can hand-prop the generator-equipped airplane, I can charge the battery en route, but the alternator won't charge the battery: I have to get a jump.<br /><br />* if I run the generator-equipped bird too long on the ground I may lose electrical services, but the alternator should have pretty much recharged the battery by the time I'm through the run-up.Aviatrixhttps://www.blogger.com/profile/13634111275860140084noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-16483081875944288372011-05-22T22:02:51.119+00:002011-05-22T22:02:51.119+00:00Re: "Generators and Alternators are significa...Re: "Generators and Alternators are significantly different creatures."<br /><br />I love how aviation includes folks with all sorts of interests, inclinations, skills and backgrounds. Which is very good.<br /><br />A few years ago someone figured out that in order for pilots to effectively fly an aircraft they could quite safely adopt a simpler view. Namely: "Generators and Alternators are basically the same thing. They make electricity so the rest of the aircraft can function."<br /><br />The airlines call it Need To Know, and it sure cuts down on training time. But it's always fun for some of us who like to know more to have a great teacher like Aviatrix and her commenters to explain the mysteries - often with some rather original analogies.<br /><br />Thanks all.Aluwingshttps://www.blogger.com/profile/16518739658424324739noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-17878885457945414482011-05-22T03:53:44.000+00:002011-05-22T03:53:44.000+00:00Thank you, good name. I am going to call it Koko, ...Thank you, good name. I am going to call it Koko, making it fit Kokopelli, the Hershey (chocolate) bar wing, and another reason that works for me. <br /><br />You're not hijacking the comments, merely diverting them, and diversions are welcome here. Especially <i>Star Trek</i>-related ones.Aviatrixhttps://www.blogger.com/profile/13634111275860140084noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-62303693487118830812011-05-21T17:18:26.603+00:002011-05-21T17:18:26.603+00:00Sorry for cluttering the comments with a double-po...Sorry for cluttering the comments with a double-post-slash-complaint (see above). It's just that the first one appeared, then vanished, then appeared again. Feel free to take the double one (and this one) down again, if you like.<br /><br />BTW, I am just now enjoying car talk on NPR. Not just do <i>car talk</i> and <i>cockpit conversation</i> sound really alike, it's also that if there ever was a really cool and witty radio show about how planes work and can be fixed, I think it should be hosted by no one else than our great Aviatrix.zbnoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-914735989876027312011-05-21T17:08:47.094+00:002011-05-21T17:08:47.094+00:00Ah, of course, Brewster, thank you. The City on ...Ah, of course, Brewster, thank you. <i>The City on the Edge of Forever</i> was wonderful, even if the whole episode p'ed off Harlan Ellison. But then, most things do.Sarahhttps://www.blogger.com/profile/09991660841701835065noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-88753152831073796772011-05-21T16:11:58.309+00:002011-05-21T16:11:58.309+00:00Sarah, "I shall try to build an airplane elec...<b>Sarah,</b> "I shall try to build an airplane electrical system from stone knives and bearskins" is an artful adaptation of an exchange in the 1967 classic episode "The City on the Edge of Forever," arguably the best original episode.<br /><br /><b>'Trix,</b> my wife would tell you that subtelty is a quality absolutely wasted on me... and I apologize for hijacking the comments.Brewsternoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-50439789253143502582011-05-21T15:46:32.838+00:002011-05-21T15:46:32.838+00:00Brewster, I'm not seeing the Trek clue in this...<b>Brewster</b>, I'm not seeing the Trek clue in this post, but Aviatrix has previously shown such proclivity. What did I miss? Some technobabble?<br /><br /><b>Anoynmous</b> Kokopelli is <i>brilliant</i>. The nose art opportunity would be excellent, which makes up for it not being a perfect match.<br /><br />Magnetism and electricity is what got me interested in technology and physics as a child. As I write this, I'm playing with some neodymium toys. How mysterious... any sufficiently advanced technology <i>is</i> indistinguishable from magic. Just ask the Insane Clown Posse. (Or much better, ask <a href="http://www.youtube.com/watch?v=wMFPe-DwULM" rel="nofollow">Feynman )</a>.Sarahhttps://www.blogger.com/profile/09991660841701835065noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-38427086442563994302011-05-21T15:41:04.439+00:002011-05-21T15:41:04.439+00:00Brewster: You make no mistake. I am astonished tha...<b>Brewster</b>: You make no mistake. I am astonished that I've managed to sufficiently subtle to only now alert you.Aviatrixhttps://www.blogger.com/profile/13634111275860140084noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-84755688122076033802011-05-21T14:31:35.001+00:002011-05-21T14:31:35.001+00:00Fascinating... here I've been following you fo...Fascinating... here I've been following you for several years (mostly in stealth/lurk mode), also back-read all your archives that I could get to, and not until today (stone knives and bearskins) have I realized that you are a Trekker!<br /><br />If I have misinterpreted your use of the phrase, I apologize. If, on the other hand, I'm blind and stating what the rest of your faithful readership already knew, then let the slings and arrows of outrageous fortune commence.<br /><br />(I am certain that, unlike me, you are not of the generation to be called a "Trekkie").<br /><br />And btw, a great read as usual.Brewsternoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-2941424187730159982011-05-21T12:15:37.238+00:002011-05-21T12:15:37.238+00:00Generators and Alternators are significantly diffe...Generators and Alternators are significantly different creatures.<br />Most Alternators will in fact self excite, but often not to levels high enough to be useful in an aircraft. Both Generators and Alternators require voltage regulators to control the output voltage.<br /><br />I've seen aircraft alternators equipped with a dry cell battery to make sure they can in fact provide power when the main battery is dead. There also exist Permanent magnet alternators, which need no external battery supply to operate. They tend to be heavier than standard Alternators, and I am not sure you really want a big magnetic in relatively close proximity to the navigation equipment.<br /><br />There are other important differences. Generators have brushes, which make and break contacts with the rotor windings seveal times per rotation. Alternators have slip rings, which make continuous contact.<br /><br />If you excite the rotor winding (most do), the current the slip rings handle is quite modest compared to the full Alternator output. The result is generally the slip rings will last as long as the Alternator. Those who are older may remember that the brushes on generators had to be replaced.They quite literally wore away.<br /><br />IN larger aircraft, the AC output of the Alternator (400hz) dramtically (about 87%) reduces the iron content required in devices like transformers and motors, so 400Hz AC is huge weight saver<br /><br />Lastly, you get can get considerably more power per unit weight and unit volume from an Alternator than from a generator.mattheww50https://www.blogger.com/profile/00898846687006155502noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-33727672959777873562011-05-21T10:17:00.891+00:002011-05-21T10:17:00.891+00:00Awesome how you explain generators. I admit I hadn...Awesome how you explain generators. I admit I hadn't really thought about how the counter-acting field is generated on start-up, maybe even throughout my entire time at college.<br /><br />A side-note: A while ago, you had a post about potentiometers. For some reason, my link to the great stories of poor Kur Killapot hasn't made it through to appearing in the comments. I tried again, because I think you might like it. Again, it appeared for some minutes, and then obviously got deleted. I really can't think of a reason why it would be offensive or considered spam. Any idea why this happens?zbnoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-33666176694209495252011-05-21T09:49:17.282+00:002011-05-21T09:49:17.282+00:00Awesome how you explain generators. I admit I hadn...Awesome how you explain generators. I admit I hadn't really thought about how the counter-acting field is generated on start-up, maybe even throughout my entire time at college.<br /><br />A side-note: A while ago, you had a post about potentiometers. For some reason, my link to the great stories of poor Kur Killapot hasn't made it through to appearing in the comments. I'll try again, because I think you might like this very special application note despite being part of a huge, scanned pdf document with odd page numbering (..., 18, 19, 2, 20, 21, ... or something). <a href="http://www.bourns.com/data/global/pdfs/OnlinePotentiometerHandbook.pdf" rel="nofollow">Here it is, inside The Potentiometer Handbook by Bourns (approx. 33 MB)</a> Be sure to check chapter nine, and also check out the cool picture of a V/STOL aircraft.zbnoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-13521364517718577982011-05-21T06:05:53.461+00:002011-05-21T06:05:53.461+00:00Kokopelli Hah! That's a good one.
If there&...Kokopelli Hah! That's a good one. <br /><br />If there's light twin with Hershey bar wings and a steel tube frame other then the Kokopelli, I can't think of it.A Squarednoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-34066192600725227332011-05-21T05:09:07.651+00:002011-05-21T05:09:07.651+00:00If the aircraft is what I think it is, I suggest &...If the aircraft is what I think it is, I suggest "Kokopelli" as a nickname. He's a Native American flute player.Anoynmoushttp://anoynmous.blogspot.com/noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-88589245570984624052011-05-21T04:27:17.187+00:002011-05-21T04:27:17.187+00:00"12 volt" generators are actually 14 vol..."12 volt" generators are actually 14 volt generators. Is that what you're getting at?A Squarednoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-78136155367995694482011-05-21T02:54:36.546+00:002011-05-21T02:54:36.546+00:00A Squared: re your first comment. That was my comm...<b>A Squared</b>: re your first comment. That was my comment on the fact that the airplane comes standard with a 12V battery and 12V generators. I'm used to the 24V battery and 28V alternators, so I was looking squinty-eyed at that purported set-up.Aviatrixhttps://www.blogger.com/profile/13634111275860140084noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-9854116378024894462011-05-21T02:44:42.226+00:002011-05-21T02:44:42.226+00:00Forget all of those silly technical terms, amp, vo...Forget all of those silly technical terms, amp, volt, and watt as they are not needed. <br />The smoke theory of electrical repair will carry you through any problems you may encounter.<br />The way this works is all electrical components contain smoke. If the smoke comes out then the part is no longer of use and you need another one.fatfredhttps://www.blogger.com/profile/04190501519025970929noreply@blogger.comtag:blogger.com,1999:blog-10000144.post-47673014560653565822011-05-21T01:56:05.248+00:002011-05-21T01:56:05.248+00:00"AC is converted to DC with a diode."
N..."AC is converted to DC with a diode."<br /><br />Not *a* diode, an arrangement of diodes called a rectifier. A simple rectifier for a dipole device would have 4 diodesA Squarednoreply@blogger.comtag:blogger.com,1999:blog-10000144.post-91620570620665593712011-05-21T01:27:42.608+00:002011-05-21T01:27:42.608+00:00Also, typically an alternator produces a higher vo...<i> Also, typically an alternator produces a higher voltage than the battery, so that it can charge the battery.</i><br /><br />Umm, so do the generators, that's the only way a battery can get charged, is by a higher voltage. Or maybe I'm not following your meaning.A Squarednoreply@blogger.com