OT - A/C Electrical systems
Moderators: wdolson, MOD_War-in-the-Pacific-Admirals-Edition
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RE: OT - A/C Electrical systems
I´m with Erkki on this one! [:D] I know Ohm law pretty good since I´m an electrician. Why I´m asking is that the losses from resistance should be negligeble over the short distances. That being said I don´t know how long the total lenght of all cabales where in and Aircraft thoses days? It guess it can add up!
- steamboateng
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RE: OT - A/C Electrical systems
I think wdolson was right on; radar & navigation systems increased power demand.
Did WWii aircraft carry IFF equipment?
Did WWii aircraft carry IFF equipment?
RE: OT - A/C Electrical systems
ORIGINAL: steamboateng
I think wdolson was right on; radar & navigation systems increased power demand.
Did WWii aircraft carry IFF equipment?
At least in Europe, many did. But I could imagine them not having being used quite often.
RE: OT - A/C Electrical systems
ORIGINAL: steamboateng
I think wdolson was right on; radar & navigation systems increased power demand.
Did WWii aircraft carry IFF equipment?
Very definitely. A lot of the fighter direction problems at both Santa Cruz and Eastern Solamons were due to a lack of (or malfunctioning) IFF gear. The carrier radars kept picking up inbound a/c without an IFF squawk and vectoring CAP to intercept what turned out to be returning a/c. When the real raids came in the CAP was dispersed from all that mistaken activity. The problem was completely solved by 44 and the Phillipines Sea and thus the Turkey Shoot.
RE: OT - A/C Electrical systems
Yep, freed by Gauss, Coulomb, and especially Millikan. I really enjoy my new found Mobility.ORIGINAL: pws1225Elmo is a free electron. He is rumored to have started the Free Love movement back in the sixties,ORIGINAL: dr.hal
Who's this Elmo dude???
And it's not a rumour, either. Shockley knew I was a coupled cluster and needed to find Hermione the unfettered Hole in order to be satisfied back to my ground state. Woof !! Being a free electron, in search of a hole is a worthy task and I can do much work as a consequence. But then I rented a billboard on the 101, just past Palo Alto (just looking for some help in my quest, you understand), and things just went from there and got out of hand. And then this Garcia fellow grabs me and promises holes galore if I would put more power into his amps, and then Jim Marshall came along, and the rest is history.
Quicksilver Messenger Service and the Summer of Love, brought to you by Elmo, your friendly Free Electron.
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RE: OT - A/C Electrical systems
Well done!
- steamboateng
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RE: OT - A/C Electrical systems
+1 JWE. But from you it may be another one of your silly cons!
RE: OT - A/C Electrical systems
ORIGINAL: Erkki
And I thought its U=RI Where =V, [R]=capital omega and =A? [;)]
ORIGINAL: witpqs
No Omega on keyboards helped to change that usage I guess, but yes I remember that. I don't recall "U" for voltage, though.
Maybe it's different customs in different countries/languages? In the US, I've always seen the equation as V = IR and the power equation as P = VI. I should have said I^2R losses in my earlier post. Not enough tea that day...
If you substitute IR for V in the power equation, you get another way to calculate power which is (IR)*I, which is I^2R. What it means is that if you have high current, your transmission losses are going to be the square of the current. Even if the resistance is low, the power lost in transmission can be big. By raising the voltage and lowering the current, the transmission losses are reduced.
There is a difference between the unit designation and the letter used in calculations. In calculations, V=Voltage, I=Current, and R=resistance. When showing a value, Volts=V, Amps=A, and Ohms=Ω (omega).
And IFF was used extensively in the Pacific. In the Aleutians ground controlled approach was also used to allow landing in zero visibility conditions. This required the plane to have extra equipment on board. My father was a photographer attached to different units at different times. He flew with B-29s at Saipan, B-25s in New Guinea and the Philippines. At the end of the war he was flying in B-25s out of Attu. He said the Aleutian B-25s were loaded down with a lot of extra electronics that wasn't on the 5th AF B-25s. The planes were very cramped inside.
Sometimes aircraft also had more than one radio and radios were large power hungry beasts back then.
Bill
WitP AE - Test team lead, programmer
RE: OT - A/C Electrical systems
ORIGINAL: wdolson
ORIGINAL: Erkki
And I thought its U=RI Where =V, [R]=capital omega and =A? [;)]
ORIGINAL: witpqs
No Omega on keyboards helped to change that usage I guess, but yes I remember that. I don't recall "U" for voltage, though.
Maybe it's different customs in different countries/languages? In the US, I've always seen the equation as V = IR and the power equation as P = VI. I should have said I^2R losses in my earlier post. Not enough tea that day...
If you substitute IR for V in the power equation, you get another way to calculate power which is (IR)*I, which is I^2R. What it means is that if you have high current, your transmission losses are going to be the square of the current. Even if the resistance is low, the power lost in transmission can be big. By raising the voltage and lowering the current, the transmission losses are reduced.
There is a difference between the unit designation and the letter used in calculations. In calculations, V=Voltage, I=Current, and R=resistance. When showing a value, Volts=V, Amps=A, and Ohms=Ω (omega).
And IFF was used extensively in the Pacific. In the Aleutians ground controlled approach was also used to allow landing in zero visibility conditions. This required the plane to have extra equipment on board. My father was a photographer attached to different units at different times. He flew with B-29s at Saipan, B-25s in New Guinea and the Philippines. At the end of the war he was flying in B-25s out of Attu. He said the Aleutian B-25s were loaded down with a lot of extra electronics that wasn't on the 5th AF B-25s. The planes were very cramped inside.
Sometimes aircraft also had more than one radio and radios were large power hungry beasts back then.
Bill
"E" for voltage is what you might find in older books in the US. I remembered it from high school. Never made sense using E, so it's good they changed it to V. You will still find E in plenty of places, just call up this Google search (I hope this link works, it's from the results page):
https://www.google.com/webhp?source=search_app#hl=en&sclient=psy-ab&q=E%3DIR+ohms+law&oq=E%3DIR+ohms+law&aq=f&aqi=g-q1&aql=&gs_l=hp.3..0i22.24752.26525.1.30685.9.9.0.0.0.0.229.1542.0j8j1.9.0...0.0.mfP-m9Q9IEI&pbx=1&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.,cf.osb&fp=ecb6a798695883bc&biw=1566&bih=907
Intel Monkey: https://sites.google.com/view/staffmonkeys/home
RE: OT - A/C Electrical systems
E stood for EMF which was electromotive force (measured in volts). The term goes back to the 1830's or thereabouts. Since it was measured in volts, eventually common usuage changed it to voltage.
RE: OT - A/C Electrical systems
That rings a bell! I'm sure a Jesuit told me that once upon a time.ORIGINAL: pompack
E stood for EMF which was electromotive force (measured in volts). The term goes back to the 1830's or thereabouts. Since it was measured in volts, eventually common usuage changed it to voltage.
Intel Monkey: https://sites.google.com/view/staffmonkeys/home
- USSAmerica
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RE: OT - A/C Electrical systems
From 1988 until I left in 1997 (and I'm sure after that time) the USN taught and referred to voltage in formulas as E. E=I*R.
Besides, you can't have my very favorite formula in all of electronics if you use V instead of E. I love to eat P=I*E. [:D]
Besides, you can't have my very favorite formula in all of electronics if you use V instead of E. I love to eat P=I*E. [:D]
Mike
"Good times will set you free" - Jimmy Buffett
"They need more rum punch" - Me
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"Good times will set you free" - Jimmy Buffett
"They need more rum punch" - Me
Artwork by The Amazing Dixie
RE: OT - A/C Electrical systems
ORIGINAL: pws1225
The higher the voltage, the lower the amperage (and associated wire size) to deliver the same amount of power.
Exactly. Ask anyone who has converted their pre-1966 VW Beetle from 6 Volts to 12 Volts. Everything just works better....
http://www.nls.net/mp/volks/htm/6v_12v.htm
Cheers,
Reg.
(One day I will learn to spell - or check before posting....)
Uh oh, Firefox has a spell checker!! What excuse can I use now!!!
Reg.
(One day I will learn to spell - or check before posting....)
Uh oh, Firefox has a spell checker!! What excuse can I use now!!!
RE: OT - A/C Electrical systems
Sir! That is a canard! The witnesses failed to testify and all the charges were dropped.ORIGINAL: steamboateng
+1 JWE. But from you it may be another one of your silly cons!
[ed] well, ok, there was that one time in Bologna, but that was Berlusconi getting pissed because I figured out how to ... oh, well, that's not imprortant. Ok, so I haven't been convicted anywhere except Italy.
- steamboateng
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RE: OT - A/C Electrical systems
The worst I'd admit to, is using a terribly bad pun in a forum.
- Capt Hornblower
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RE: OT - A/C Electrical systems
I don't know if anyone's still looking at this thread, but the E in E=IR stands for emf (which is electromotive force). E is the symbol most commonly used in physics because emf is understood to apply to all situations where an electric field exists, whether from the dynamic flow of electrons or from the static separation of electric charge of any sort. (V is used especially by electricians, who don't need to be formally trained in physics.)