From the course: CompTIA A+ Core 1 (220-1101) Cert Prep

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Choosing a power supply

Choosing a power supply

From the course: CompTIA A+ Core 1 (220-1101) Cert Prep

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Choosing a power supply

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- When we're buying a power supply, we buy it based on watts. Now, before I get into a lot of detail on watts, I want to kind of correct something I said that wasn't 100% true earlier. When we talk about electricity, we always say volts times amps equals watts. Well, that is absolutely true, but only in a perfect world where we have 100% perfect efficiency. What's really happening is that power supplies, like anything on earth, are not perfectly efficient. So when you plug into your wall outlet, only a percentage of that electricity that you're getting from the wall outlet is being converted into the DC voltages that your PC needs. The rest is lost through heat, friction, other things like that that prevent you getting all the electricity goodness that you need. And this has been a big problem with power supplies over the years. So first of all, when you're looking at power supplies in the store, you can see they've all got these wattage ratings on 'em. So on these two in particular…

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