# What is the operational difference between a 60Hz/120VAC outlet and a 400Hz/120VAC outlet?

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Additionally, is it safe to feed a 50-60Hz device, like my phone charger, 400Hz/120VAC?

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The 400Hz outlet is oscillating a lot faster between the min and max voltage. Whether this makes an operational difference depends a lot on what device you’re plugging in.

Stuff that is pegged to the frequency, like an AC motor or clock, will *not* work properly on 400Hz. Don’t do it.

Stuff that works on DC doesn’t inherently care but the filtering circuitry converting from AC to DC may or may not care depending on how robust it is, how it was built, and whether it was designed to handle 400 Hz or not. Generally, don’t assume it will work. The voltage *transients* in 400Hz are much higher, which can totally screw up some components.

The V is voltage. It’s one of the dimensions of electrical power.

AC means that the voltage pulses back and forth from positive to negative rather than staying at a fixed value (that would be “DC”).

**The Hz is** ***how fast*** **the voltage pulses back and forth.**

Way back when household electricity first became a thing, 50-60Hz were chosen because electricity at those frequencies would have relatively little leakage over long transmission lines.

But another thing about AC electricity is that *transformers* are much more efficient at *higher frequencies*. So the aviation industry chose to use 400Hz because it would allow them to use much smaller transformers on planes, where every pound counts.

As mentioned by another commenter, I would definitely not try using a device meant for one on the other.

400 Hz is obviously higher frequency. Because of this you can use much lighter and smaller electrical components. However, transmission losses are much higher than 60 Hz, so it’s only used within an aircraft or building. I’m guessing you’re in an aircraft or an old server room?

You have a good chance of burning out your 60 Hz device if you connect to it, and certainly don’t connect anything that uses the power to directly run an electric motor. You might get lucky if it’s a switch mode power supply in your phone charger, since they can usually handle large frequency variations, but you run the risk of lowering its useful life even if it does work.