Electrical Question

Roger Roger said:
AC advantages: easy to step voltage up and down with minimal losses in efficiency, some components work really well with it (any motor that needs to run at a constant speed, lots of avionics components).
AC cons: I'm pretty sure it's witchcraft with all that current leading or lagging voltage and parallel RLC circuit nonsense, AC motors aren't optimal for all applications, you have to have monkey motion like CSD units or solid-state VSCFs to keep a constant frequency as engine rpm changes, did I mention it's like voodoo?, you can't really store AC in a battery.

DC advantages and disadvantages are pretty much opposite of AC.

Alternator vs generator is kind of semantics, in this context I'm guessing that the desired answer is that a generator pumps out AC while an alternator has a built in rectifier so it puts out DC. However in GA land a generator is a device that puts out DC via brushes and a commutator instead of slip rings and a rectifier.
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You're a slip ring!
 
hook_dupin said:
People don't realize how broad EE is. My wife is also an EE, but she loved power systems. Load balancing, lag shifts, etc ...I just didn't get it. I loved embedded systems... the idea that you could create code to etch individual gates was amazing to me. My wife hated that stuff, and we never studied together.
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True story.
 
Richman said:
We were just the "Doesn't fit? Hit it with a hammer. Still doesn't fit? Get a bigger hammer, and some moly grease" MechEs.



Richman
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Ok, tangent time. There was something I noticed in college-all the engineering guys were tinkerers, modding cars (the campus auto club was basically the MechE department), fabricating cool stuff in the welding lab, etc. By extrapolation that tells me that engineers aren't the stereotype eggheads in lab coats with no hands on experience that your average mechanic visualizes. So why in the bleep are they so bad at thinking of the poor bastard that has to work on their product after it's put in service? The only thing more universal than the back and forth between pilots and mechanics is the unbridled hatred mechanics of all types (at least all types I've worked with) have for the engineers who designed their equipment.
 
Roger Roger said:
Ok, tangent time. There was something I noticed in college-all the engineering guys were tinkerers, modding cars (the campus auto club was basically the MechE department), fabricating cool stuff in the welding lab, etc. By extrapolation that tells me that engineers aren't the stereotype eggheads in lab coats with no hands on experience that your average mechanic visualizes. So why in the bleep are they so bad at thinking of the poor bastard that has to work on their product after it's put in service? The only thing more universal than the back and forth between pilots and mechanics is the unbridled hatred mechanics of all types (at least all types I've worked with) have for the engineers who designed their equipment.
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Just remember this public service announcement:

"Mad Scientists don't build giant evil robots....

Mad Engineers do."

The more you know.....

Richman
 
Roger Roger said:
Ok, tangent time. There was something I noticed in college-all the engineering guys were tinkerers, modding cars (the campus auto club was basically the MechE department), fabricating cool stuff in the welding lab, etc. By extrapolation that tells me that engineers aren't the stereotype eggheads in lab coats with no hands on experience that your average mechanic visualizes. So why in the bleep are they so bad at thinking of the poor bastard that has to work on their product after it's put in service? The only thing more universal than the back and forth between pilots and mechanics is the unbridled hatred mechanics of all types (at least all types I've worked with) have for the engineers who designed their equipment.
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Agreed. I suspect the engineers only look at whatever little portion of a system they've been tasked with designing, everything is easy to get to and work on when it's sitting by itself in a lab. The problem arises when 1000 of these little projects are stuffed together to make an airplane. Not to mention any modifications that get incorporated during production or added later in an aircrafts life. We have a guy at my shop right now that's in the middle of a throttle cable change on a G-IV, he started on the 1st of the month and he's probably 3/4 of the way to being finished. You won't hear a single complaint from anyone about the amount of time it's taking, we've all done it in the past, they literally build the airplane around some portions of the cables/pulleys. Luckily he's a very even tempered guy, but I have to admit to giving anyone doing that job a wide berth until it's done. I'd like the engineer responsible to come to the hangar and give it a whirl just once. Don't even get me started on the freon A/C system on a Lear 55. Sometimes you just have to commit to disassembling half of the airplane to replace a $15 part or inspect something that you've never found, or heard of being found unairworthy. I suppose we all have our own crosses to bear.
 
Roger Roger said:
Ok, tangent time. There was something I noticed in college-all the engineering guys were tinkerers, modding cars (the campus auto club was basically the MechE department), fabricating cool stuff in the welding lab, etc. By extrapolation that tells me that engineers aren't the stereotype eggheads in lab coats with no hands on experience that your average mechanic visualizes. So why in the bleep are they so bad at thinking of the poor bastard that has to work on their product after it's put in service? The only thing more universal than the back and forth between pilots and mechanics is the unbridled hatred mechanics of all types (at least all types I've worked with) have for the engineers who designed their equipment.
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Usually, it's the collision of engineering with accounting.

Engineer: "This is the best thing ever!"

Accounting: "That has a 3% margin and huge tooling costs. Can you make something that costs half as much?"

Typically, maintain ability is the first to go, as the buying customer usually doesn't have to fix the thing.
 
Roger Roger said:
. So why in the bleep are they so bad at thinking of the poor bastard that has to work on their product after it's put in service?
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The biggest reason is that the employer of said engineer almost always wants the cheapest solution, not the best one. Design For Manufacturing (DFM) is a big factor too - assembly steps are probably given much more consideration than maintenance ones. To a lesser extent, parts commonality factors in as well. Smaller BOMs are cheaper, so if there is a way to make do with 3 of one part instead of 1 ea. of two different ones, that's a good choice. Designing any subsystem is expensive, so they tend to get reused where possible as well. So even something that was designed with ease of maintenance in mind may become a pain when it is bolted on to another product.
 
Roger Roger said:
Ok, tangent time. There was something I noticed in college-all the engineering guys were tinkerers, modding cars (the campus auto club was basically the MechE department), fabricating cool stuff in the welding lab, etc. By extrapolation that tells me that engineers aren't the stereotype eggheads in lab coats with no hands on experience that your average mechanic visualizes. So why in the bleep are they so bad at thinking of the poor bastard that has to work on their product after it's put in service? The only thing more universal than the back and forth between pilots and mechanics is the unbridled hatred mechanics of all types (at least all types I've worked with) have for the engineers who designed their equipment.
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Like mosy thing, its managements fault. My old man started at a manufacturer and they had "the thinnest, wirery circus freak every" to prove that someone could swap a part out. Engineering always gets pissed at the choices made by management, but once it gets tossed to the draftmen, draftsmen... whatever, it is draw up, modeled, and that wirery, sallow faced, assassin of joy would come in and slither into some bs hole to change a part. Then he'd go back to the game room.
 
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