Name: Powering stuff when there is a power outage
Uploaded: 2017-07-20T12:58:22.000Z
Duration: 6 min 26 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Hi! I spent the new year's countdown in the dark

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because there was a power outage and half the city was out.

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I finally thought of a  solution, though, but...

See, I have this power inverter for use in a car.

or directly to the 12 V battery and it generates AC output.

So you can use it to power your stuff at home.

but you might have a battery-operated drill

that runs on a 12 V or 14 V battery. Then, you're set!

My luck is sh*t. I never connect it right the first time.

Are you kidding me?! Not only it's completely broken,

its 50A fuse is blown. Who designed this s***?

Reverse-polarity protection reliant on a 50A fuse to blow?!

Seriously?! It's like cutting your d*** to prevent pregnancy.

I replaced the fuse, and now, if I connect my Mooshim multimeter

to the input terminals of the inverter in reverse,

I can clearly see that there is a diode drop voltage across the terminals.

This is the circuit they have. If you connect the battery here,

But if you connect the battery backwards, like this,

then the diode forward-bias and there is a huge current

And it can't even protect the circuit here!

Even their datasheet says “reverse polarity connection will result

in a blown fuse and may cause permanent damage to the inverter.”

Well, this is bulls***. Now I have to buy a new inverter.

Okay, let's see. Is there anything on sale?

Let me test a couple of these and see if it has the same crap circuit.

Wow, even the Cat has the same crappy protection.

Seems like the same person designed all of them.

Dear inverter designers, this is the circuit you need.

Keep your fuse, change  your diode to a TVS diode

and use a MOSFET in this configuration for reverse-polarity protection.

so we can measure the current and voltage on my phone.

Here we go. You have around 5 A from the battery at 12 V,

This is good, but it drains my puny drill battery quickly.

And you see, it only draws 1 A, or 12 W, from the battery.

So this is going to last much longer and provides the same brightness.

Now, I'd like to plug my inverter into the outlet of my house

And for that I made this harness that you can plug to both sides.

Any time you connect the power harness, connect it to your load side first,

so you wouldn't short your power supply or shock yourself.

This is probably the most stupid harness one can make,

because it exposes high voltage on both sides.

Yes, we have to make sure our load is not powered from a different source,

The issue is that although both these sources are 120 VAC,

and the green wave is the output of the inverter.

You can see they don't have the same shape,

they are not in-phase, or even have the same frequency.

So connecting them together shorts their voltages badly.

So, in order for me to power a room from a plug,

I have to disconnect the main power and some heavy loads,

because my inverter cannot take that much power.

It's better and easier if I just disconnect that specific room,

Always make sure you open the correct breaker

by connecting the light or something into the plug.

But here's a redneck way of knowing which one is the correct breaker.

Just short the plug in question and the correct breaker opens.

One thing you should realize is that your phone line, or internet,

doesn't disconnect when there's a power outage.

The problem is that my puny  drill battery can't last for long.

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Powering stuff when there is a power outage

apparently

crap

bias

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