Hey folks, Cooley, like many of you working from home.
But always thinking about contingency planning.
Whether it's in this pandemic or some future event.
One of the things that comes is how do you power things in your car.
Maybe you gotta be on the go, maybe you gotta to evacuate.
I'm not talking about things like phone, that's easy.
We know how to do this.
What about when you wanna plug in your laptop in your car, and it wants to see.
Regular household outlet.
That's where you buy something called an inverter.
This guy gives you household style outlets in your car.
Let's find out how to buy one of these and how to use it.
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This thing's called an inverter, but it doesn't really tell you much invert.
What, what it does is take the very different electricity in your car which is typically 12 volts direct current and turns that into nominally 120 volts alternating current.
Now direct current does this it's a straight line basically, if you want to imagine it that way.
Alternating current does this.
You've seen these sine waves.
And that means it flips polarity as it flows through wiring.
So not only the voltage level, but the voltage type is very different between DC in your car and AC that your laptop wants to see.
The inverter fixes that with a number of internal tricks.
Now there are no interesting moving parts inside of an inverter to show you that will explain how it works.
So I'll do it graphically and my apologies in advance to you who is in the audience.
Here is household alternating current, it goes 120 volts in one direction.
Or polarity, then it flips polarity and does 120 volts the other way?
It does that entire cycle you see there 60 times every second.
Let's compare it now to DC or direct current again, compared to a baseline.
It doesn't flip.
It doesn't change.
It doesn't really even have a waveform.
Now the voltage is also different.
In the car example it's only 12 volts, but more than the voltage notice the difference in waveforms.
That's our big challenge.
So what does the inverter do to try and fix that?
Imagine if you had a battery and you had it one direction, then you flipped it the other direction and could do that very quickly with your hand.
Let's say you want to have created a very simple crude form of alternating current.
But notice it's a square wave, not a sine wave.
The things you plug into household outlets are designed to see a sign wave.
That's what they really wanna see, especially if they're delicate electronics.
So how do we make the one look like the other?
Going back with our battery analogy now, if you take that battery in one direction on the left And take increasingly growing and then receding doses of power from it, you end up with something that looks very different from the square wave we're trying to get away from.
We've made some real progress.
Now, if you take that and tuck it up underneath our AC sine wave, notice how it starts to look an awful lot like it.
We do the same thing with the battery flipped, and we have the other half of the AC way.
This is the heart of what an inverter does turning DC into a decent facsimile of AC and also adjusting the voltage up.
Okay, now we know what an inverter does and how it does it.
Let's figure out how to buy one.
The first thing you want to do is look for one that really has good quality sine wave conversion, one that does a good job of creating this from this.
Your equipment that you plug into this thing will thank you for a high quality, faithful recreation of a sine wave from straight line DC Second of all, I like good, heavy build quality in anything that generates significant power or converts significant power, which these do.
This has got good heft to it.
It's a name brand.
It's got a nice, heavy cable that connects it to the car.
All of those give me confidence.
It's also got safety systems, a fuse in the back in case it gets overloaded.
And inside here Circuit breaker that will go off momentarily if it gets overheated and instructions right here on the device itself on how to recycle it.
If it does get overheated and you want to bring it back.
Another thing to look for, I guess my third point is your output.
This is the biggest thing you're going to ask is how many watts will this thing support it says right here on the outside?
This 1375 watts.
It should be an easy spec to see on any one of these D rate that assume you've got 80% of that, not 100% of that just to be safe and there's probably a safeguard built in and then see how How much your stuff draws this laptop charger.
It's almost impossible to read but it's 65 watts.
So that takes a chunk out of my 375.
Then add up what else you're going to put in there.
Maybe you're gonna charge two laptops.
Now you're up to 130 Maybe you're going to charge a bunch of drone batteries as you're on your way to a drone shoot, one of those chargers dropped.
Add that all up and again, keep a cushion, and then you're in good shape.
But last thing is if you do use one of these almost constantly, regularly, and especially a big one that draws more than this You might wanna have it hardwired into your car's electrical system.
In other words have a home run wire that goes to the battery, not this thing that goes into essentially a cigarette lighter as we used to call them a 12 volt outlet.
Those things aren't really meant for constant high current transfer.
A hardline to your battery would be better.
Bonus points, if your car has an available heavy duty alternator, that'll charge the battery better as the inverter draws it down.
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