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tezoatlipoca t1_jefjvfd wrote

In an AC or alternating current power line, the current flows first one way, then the other. The current, and/or the voltage if you want to think of it that way, literally changes direction (or from +V to -V) following some type of periodic or cycling wave: a square wave, or a sine wave.

The problem is, a lot of power sources that aren't large turbine or rotationally driven generators tend to produce DC or direct current - which does not alternate. Solar panels, batteries etc.

So what a power inverter does is convert a flat Direct Current into a sinusoidal - or at least periodic, repeating - wave. One does this with mechanically flipping switches or relays or with transistors (or derived digital logic circuits), which are really just silicon based switches. For half of the cycle it sends current one way, for the other half it sends current the other way. By designing the output of that circuit carefully with the right components you can essentially get a square wave. By adding removing some additional harmonics with additional switches and components ((diodes, resistors, capacitors)) you can change the shape of that square wave into a sine wave.

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Ape_Togetha_Strong t1_jefkk3e wrote

This feels like a completely post-hoc explanation. If you have a real source, I would love to read it.

Seems much more likely its called an inverter because it performs the inverse operation of an already established device, the rectifier.

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nighthawk_something t1_jefkp8a wrote

First you use diodes to turn the negative part of the AC wave positive.

So now you have a bunch of bumps that are all from 0 to 110V (in the case of 110VAC).

Next you use capacitors to store energy from the bump so the voltage doesn't drop anymore.

Then you add resistance to bring the voltage down to what you want to use.

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1nd3x t1_jefmthk wrote

That wave is more like the "pressure of the electricity" where more voltage means it goes further above/below zero, and the direction of that pressure(forward or backwards) is decided based on if it's above or below the zero line.

If it was a hose of water it's like turning on the tap and having water flow out of the hose, then get sucked back into the hose over and over.

For a brief moment there is no push or suction...that's your "0 point" otherwise it's either pushing the electrons down the wire. Or sucking them up the wire which means any individual electron might not actually "move" very much, much like the specific water molecules at the end of the hose would just go in and out of the tip rapidly...so too does the electrons

While DC power is a flat line at whatever voltage it is and that's more like a hose just shooting water out of it at a steady rate.

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konqueror321 t1_jefq0ww wrote

So an inverter generator would convert the raw generator AC output into DC, then convert it back into AC output as you described, 'cleaning up' the raw AC current so it is safer for electronic devices?

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SoulWager t1_jefs437 wrote

Inverter can either refer to a NOT logic gate, or a power supply that generates AC from DC.

The logic gate inverter turns a 1 into a zero and turns a zero into a 1. On a schematic it looks like a little circle on the input or output of a logic gate or buffer.

The power supply inverter might have been more accurate to call a power oscillator instead. As most commonly used, what it does is it takes a DC source like a battery or solar panel, and repeatedly flips the polarity to make AC. There's usually also a voltage conversion happening.

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geekworking t1_jefske9 wrote

Yes. The electronic inverter circuit is what is creating the AC output and this can be carefully controlled to give a clean and consistent output. High end online type uninterruptible power supply (UPS) systems designed to protect sensitive computer equipment work in a similar way to take power from the wall outlet or its batteries to always make clean power.

The other advantage to inverter generators is that they can slow down the engine when less power is needed. This saves a lot of fuel and makes them less noisy most of the time. Normal AC generators need to always run a full speed to provide the proper output frequency.

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Flair_Helper t1_jeg9xem wrote

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DeusExHircus t1_jega44y wrote

ELI5: You've got DC+ and DC- coming in, and AC1 and AC2 going out. Hook up + to AC1 and - to AC2, power goes forward, a crest. Now switch the cables quickly, - to AC1 and + to AC2. Now power is going backwards, a trough. Keep doing that 60 times a second and you've become a simple square wave inverter. Replace you with some circuitry and it's automatic. Normally you use more complicated components to generate a sinusoidal wave but the gist is the same, keep switching the DC input forwards and backwards and it creates the AC voltage wave

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beavis9k t1_jega7k5 wrote

Minor correction, if I may: harmonics are removed or canceled out to get a sine wave. A pure sine wave has only one harmonic (the fundamental). A pure square wave is the fundamental and the odd numbered harmonics.

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