You probably do this all the time, but you don’t even know it.
I’m talking about AC power calculations with P = V x I.
Technically, it works. But when you think about it, it shouldn’t. AC has constantly changing voltage and current over time – unlike DC.
So how on earth does it work?
Well, the short version is: RMS, or root mean square!
I recently learned the hard way what’s happening with smart meters in Europe. The same type of smart meter they’re using here in France has already been deployed in many EU countries.
Mostly, we hear only about the negative health effects of wireless smart meters, but the ones here only send data back over the power lines.
Nevertheless, it turns out smart meters here are still being used to pretty much screw many over.
In short, smart meters may mean less juice to power stuff, and more frequent main breaker trips as people exceed their (now reduced) capacity.
If you’ve ever accidentally chopped through a wire or electrical cable, you know how much fun it can be to try to repair it so that it stays waterproof, dust proof, weatherproof, etc.
I recently had just such a fun experience myself. It turns out that there are quite a few nice products out there to make the splicing process WAAAAY easier.
Keep in mind that the type of splice you use depends greatly on the application – and even the type of wire (solid vs stranded).
A wire splice for an automotive-type application must be pretty strong, because vibration is obviously an issue.
An underground electrical cable doesn’t have to withstand vibration, but it definitely needs to be waterproof!
Extension cord reels, or rolly cords as I like to call them, are seriously handy.
Nobody likes spending 30 minutes untangling a 50m extension cord.
Trouble is, usually we use them incorrectly!
It turns out you have to read the fine print: You can only use the full capacity of the reel if you fully unwind the rolly cord.
Oops!
First, remain calm. Second, watch this video!
A tripping circuit breaker or GFCI/RCD/differential breaker can be really annoying. It normally doesn’t happen.
When it does, the end result can be that you run around the room with your undies on your head, screaming like a wildperson.
Obviously, if your vacuum cleaner is charred and black and there’s a funny smell in the room, you’ve just figured out why the breaker tripped. But usually, the problem is a bit more subtle than that…
It turns out that with a bit of work, you can often cleverly narrow down the problem to one gizmo and save yourself some money – without setting anything on fire!
Yay!
Power factor is one of those things that sounds really complicated, but it’s pretty simple when you boil it down. And every now and then, knowing a little something about power factor comes in handy.
In short, power factor is the ratio of the real power consumed by a gizmo to the apparent power needed to be generated and delivered by the power company.
The reason for this “extra power” from the power company is the inductance and capacitance in your gizmo that results in shifting the AC current sine wave away from being perfectly in sync with the voltage sine wave.
You don’t really need to understand how all that works; just watch the vid to see why it matters!
Why does AC electrical power come in 3 phases? What the heck is a “phase”, anyway?
In this episode of the EEK! Series, you’ll learn about 3-phase power and its advantages.
In short: fewer wires, more power, and the Earth itself is a conductor.
In addition, 3-phase industrial motors are more efficient and don’t require a starting capacitor since the 3 phases are “rotating” already.
In episode 2 of the EEK! series, we cover the basic difference between direct current (DC) and alternating current (AC). Why is your home powered by AC, and not DC?
Simply put, AC allows the use of transformers to step up the voltage, step down the current, and therefore bypass the little problem of too much current flowing over a thin wire.
DC cannot be easily converted in this way for efficient power transmission over long distances. There’s more to say about AC, so look for a 3-phase video soon.
Check out the video below!
Solar USB chargers are all the rage these days.
The most popular models are small, and many have integrated lithium-ion batteries.
But just how good are these things? Will you be happy with a small one, or is it better to supersize it?
In short, get a big one! Smaller solar panels just don’t output enough current to make them really worth the price.
These days, it’s all about energy efficiency.
In some countries, you can hardly even buy normal incandescent light bulbs any more. You are left with a choice of slightly more efficient “a bulb inside a bulb” halogen options, or compact fluorescent light (CFL) bulbs.
Well, there are some problems with CFL bulbs, as we shall see.
Now, LED bulbs have made their big debut on the scene. They use even less power than CFLs, and supposedly they are better for the environment and all that jazz.
In some ways, this is true – but at a cost unless you are careful about which LED bulbs you pick.
And, since LED bulbs are so darn expensive, you need to choose wisely. Here’s how…
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