Subtitles section Play video Print subtitles Hi! I spent the new year's countdown in the dark because there was a power outage and half the city was out. I finally thought of a solution, though, but... 2016 was already gone! See, I have this power inverter for use in a car. You connect it to your cigarette lighter or directly to the 12 V battery and it generates AC output. So you can use it to power your stuff at home. You can't drive your car into your home, but you might have a battery-operated drill that runs on a 12 V or 14 V battery. Then, you're set! Let's connect it up. I probably connected it backwards. My luck is sh*t. I never connect it right the first time. F***! Now it doesn't work?! 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, the current goes through the fuse here and powers the circuit here. But if you connect the battery backwards, like this, then the diode forward-bias and there is a huge current through the fuse that blows the fuse. 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.” Absolute garbage. Well, this is bulls***. Now I have to buy a new inverter. This wasn't even the focus. 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. Huh. This has a diode drop, too. Wow, even the Cat has the same crappy protection. Seems like the same person designed all of them. Let's just get the cheapest one. 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. Anyway, I have my drill battery and I've hooked up my Mooshim meter, so we can measure the current and voltage on my phone. Now, we connect the battery... and turn on the inverter. Here we go. You have around 5 A from the battery at 12 V, which draws 60W from the battery. This is good, but it drains my puny drill battery quickly. So, instead... I can use an LED light. 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 so I can power more things. And for that I made this harness that you can plug to both sides. First, you plug it to the inverter... [Pain and profanity] 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. ♪ I'm only human, after all ♪ This is probably the most stupid harness one can make, because it exposes high voltage on both sides. So, don't make it. Let's very carefully plug it in. Yes, we have to make sure our load is not powered from a different source, like the BLEEPING city power! The issue is that although both these sources are 120 VAC, they are different in many ways. The yellow sine wave is the city voltage 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, like the washer and the fridge, because my inverter cannot take that much power. Actually, that's pretty dumb. It's better and easier if I just disconnect that specific room, which I believe is breaker #3. Now we can safely plug them in. [Super girlish scream, bleeping] Apparently, it was breaker #2. 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. Hahaha! Don't do it! One last try. There! It's working. Two lights, my phone—all working. One thing you should realize is that your phone line, or internet, doesn't disconnect when there's a power outage. So this way you can bring them back. [BEEEEEEEP!] Oh, now my inverter is complaining. The problem is that my puny drill battery can't last for long. But if you have one of these larger batteries, like this one for example, that has 7.2 amp-hours, it can last for much longer. Let's turn on the TV by my inverter and measure the current. It is drawing 16 A from 12 V, so it is around 200 W. My battery is 7.2 amp-hours and drawing 16 A from it will shorten its life quicker. We need a car battery. With this, I plug the entire setup into my inverter. The TV, digital box, my phone, the radio and even the light. This setup is drawing around 22 A from the battery, and my battery is around 75 amp-hours, which means it'll last for more than 3 hours. So I'm set. Okay, let's return the battery. Let's try it. [Engine trying to start] [Profanity] [Engine still trying to start] You know, there are these things called UPS, or uninterruptible power supply, that output AC, have their own battery and charge it, too. Maybe they are worth the investment. You know, this Mooshim meter has become increasingly handy. It would be ashame if I had to give it away. Yes, I'm giving away 10 Mooshim meters to my Patreons at Patreon.com. No matter what Mooshim means in German. You can also buy it from these sources. And, you know, I want to make some secret videos that I don't want everyone to see, available to my Paterons. Hopefully that's a good idea.
B1 inverter battery fuse plug diode power Powering stuff when there is a power outage 186 5 共用 posted on 2017/07/20 More Share Save Report Video vocabulary