400 hz

[domnic]

What is the advantage of useing 400 hz in airplanes and where else is it used?

 

[LarryFine]

What is the advantage of useing 400 hz in airplanes and where else is it used?

Motors and transformers can be smaller and lighter for a given power with the higher frequency.

 

[domnic]

400 hz

So what is the down side of 400 hz and wy dont we use it more?

 

[BJ Conner]

What is the advantage of useing 400 hz in airplanes and where else is it used?

A two po;e motor has a speed of 24,000 RPM.
Sperry made the first gyrocompasses. You need a fast motor to make a groscope. This goes way back in history.

 

[dbuckley]

So what is the down side of 400 hz and wy dont we use it more?

Because the capacitive losses go up with frequency.

It doesn't matter much a hundred feet of 12/2 at 120V, but at 66KV and a few miles, the losses would become extreme.

 

[iwire]

So what is the down side of 400 hz and wy dont we use it more?

Voltage drop. (Just a less technical explanation than above)

 

[jim dungar]

Also, skin effect and proximity effect are both factors at 400Hz.

 

[stantonlw]

Aviation

Aviation

The main reason, and the one that remains today, is that the "magnetics" are so much lighter. In aircraft design, we sweat gallons to reduce the nonpayload (non-paying) weight by a few pounds! For a given mission, if you increase the aircraft weight by a pound, you increase the required fuel by several pounds which means that you have a smaller payload unless you build a bigger aircraft which costs a lot more.

Larry