FourierXFM

FourierXFM t1_ixdbot3 wrote

>Then you learned it wrong. (Or just a simplified explanation) I have a bachelor's in EE, the standard convention for the terms is that any signal that is not DC is considered AC.

I don't mean to get into a pissing contest, but you're being rude, so I will. I have a masters in EE with a specialty in power electronics focusing on AC/DC conversion. I promise I did not learn it wrong.

Alternating means back and forth, or positive and negative. A full bridge rectifier with no capacitive filter at the end is still called DC even though it's oscillating up and down.

At some point of ripple you would be more right to say it's DC with an AC component, but nobody in industry calls that alternating power... because it's not alternating.

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FourierXFM t1_ixd0o2n wrote

I have never heard it that way. Alternate means to change direction. The power is not changing direction.

I have never heard someone call a DC voltage with a high frequency ripple as "alternating", even though that is kind of the same as what you're talking about.

People do say AC power a lot, but AC means alternating current, which is true. Not alternating power, which is not true (again, all assuming pf = 1).

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FourierXFM t1_ixcqhdi wrote

There's one thing I think most people are forgetting. Let's assume a power factor of 1.

Voltage is alternating (it is a sinusoid). Current is also alternating (it is also a sinusoid). The power is NOT alternating.

If power factor is 1, the current and voltage are in phase, which means they positive and negative at the same time.

So when voltage is positive, current is positive. Power = voltage * current, and both are positive, so power is positive.

When voltage is negative, current is negative. Power = voltage * current, and both are negative, so power is still positive.

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