Why 400hz

Aircraft electrical components operate on many different voltages both AC and DC. However, most of the aircraft systems use volts AC at hertz or 28 volts DC. AC power, normally at a phase voltage of V, is generated by an alternator, generally in a three-phase system and at a frequency of Hz. Running at v Hz allows the use of smaller transformers. Less energy has to be stored in the transformer core per cycle, so the core can be smaller.

A smaller core means a lighter transformer, and reducing weight is a good thing in an aircraft. Air Force Aircraft Electrical and Environmental System Specialist F-4, F, A, UH-1, and others, not only does the 3-phase Hz reduce the size of the components on the AC portion of the power supply, but it also rectifies into a DC that requires smaller and fewer components for filtering.

The period for rectified 3-phase 60Hz is 2. Luckily is distance of cable runs on a plane, aircraft etc. More passages through 0 volt potential will help to extinguish the arc, moreover can added short circuit protection be built in in form of short coils XL. How to convert single phase to three phase power? For small hobby type applications or basic agricultural requirements where you just want to get a small three phase supply to power a lathe, drill, drive belt etc there is a basic device called a If an airplane is too heavy, it may not be able to take off.

At the very least, it will require a more powerful engine or engines. Aerospace manufacturing companies can achieve a lower weight by using Hz power. With Hz, airplanes require fewer generators or alternators to produce a sufficient amount of power. This reduces their total weight, thereby making it easier for airplanes to take off. If airplanes used a lower power frequency, they would require more generators or alternators, thus increasing their total weight.

Another reason why Hz power has become so common is because it allows for the standardization of electrical devices and components. Rather, some devices and components would be restricted to certain airplanes. Using Hz power ensures creates a standard for electrical devices and components.

Since most airplanes use Hz power, their devices and components can be easily replaced. Viewed 28k times. Improve this question. Ralph J. Ralph J Ralph J The second question IS a duplicate question, although the answer there is terrible, and neither one shows up when looking for " Hz" as a search. If I were searching for the answer to Hz vs 60 Hz, "Why do airplanes use AC" wouldn't be an obvious place to look for the answer. Furthermore, if you can find a way to make that 2nd link not be a dupe of the 1st which it is currently marked as , you could find a way to reopen it, thus allowing you to add your answer there.

Or if you can find a way to add your answer to the 1st link currently open , that works too. We could perhaps petition a mod to re-close that second question as a dupe of this one, or merge them. That's also why the second question which doesn't really have a valid answer to the question which was asked has the first question as its' duplicate. See this answer which addresses your question: aviation.

Show 1 more comment. Active Oldest Votes.