Power Supply Units explained

[usil]

Alright guys, its time for me to learn about PSUs. Besides looking at the Watts I know nothing about them. I am an ignoramus when it comes to electricity, so give it to me slow and easy. Volts, Watts ? :eek:

[SpywareDr]

General Volts, Amps and Watts info:Volts x Amps = Watts

Watts / Volts = AmpsSo, for example, 120 volts times say a 15 amp breaker equals 1800 maximum watts. (A hair blower is usually around 1,000 watts, an iron maybe 1,500 watts, and a 100 watt light bulb = 100 watts :)).

Another example. Let's say you wanted to know how many 60 watt light bulbs you could run on a 15 amp breaker. 60 watts divided by 120 volts equals 0.5 amps each. 15 amps divided by 0.5 equals 30 light bulbs.

[usil]

Another example. Let's say you wanted to know how many 60 watt light bulbs you could run on a 15 amp breaker. 60 watts divided by 120 volts equals 0.5 amps each. 15 amps divided by 0.5 equals 30 light bulbs.
I'm afraid you completely lost me there! :eek:

[SuperSparks]

Let's start with the very basics. Think of electricity like plumbing.

The voltage is the pressure of electricity, it's directly analagous to the water pressure in your plumbing system. So the higher the pressure, the more water or electricity can be forced down a given pipe or wire.

Current, measured in Amperes (Amps for short), is the amount of electricity. It's the same as how fast the water flows through the pipes when you open the tap.

Resistance, measured in Ohms, is a little harder to explain, but think of it as an opposing force to water flowing down a pipe or current flowing down a wire. The thicker a water pipe, the less resisteance to water flow, and it's exactly the same with electrical resistance, the thicker the wire, the less resistance there is. With electricity, the resistance is also determined by the material that the wire is made from as well as it's size, silver being the best conductor, copper next and then aluminium.


Once armed with those basics, you can determine any value so long as you have the other two, using Ohms law. The formula is:

V = I * R (Voltage = Current * Resistance).


Here endeth lesson 1 :D

[SpywareDr]

I'm afraid you completely lost me there! :eek:

How about:60 watts divided by 120 volts equals 0.5 amps per light bulb.

15 amp breaker divided by 0.5 amps per light bulb equals 30 light bulbs.

[Train]

usil

Maybe this search will help gather the background (http://www.google.com/search?hl=en&q=Basic+electricity) you seem to be wanting.

Thik of Volt as the pressure that pushes the amps through the lines so work can be done.

[usil]

So far, so good... lesson two :)

[bistro]

I'm afraid you completely lost me there! Ok...putting it a little simpler....don't drink your Coke anywhere near the psu. PSU voltages/amps and liquids do not get along with each other very well.

Next lesson we'll discuss curbing your mechanical curiousity and not putting your fingers inside the psu, standing with bunny slippers on a shag carpet and wearing that wool sweater Aunt Biddy gave you for Christmas....

Pretty decent article on PSUs (http://extremetech.com/article2/0,1697,1815446,00.asp)

[usil]

I'd been waiting for that lesson Bistro. Heard it was a killer! :D

[Train]

A number of years ago we had someone post where he had a spark jump from his finger to hit tower and wondered why it would not boot up. We found out he was wearing a wool sweater and wools socks and had to walk on a nylon rug to get to the computer.

Well, he was able to salvage the case in the end. Everything else was fried. :(
Seems the spark jumped about 2 inches to hit the tower.

[bistro]

Good grief and yikes! http://www.clicksmilies.com/s0105/aktion/action-smiley-021.gif That had to be at the very least 10,000 volts...probably higher. Cold, dry winter air, overheated (dry) rooms, wool, nylon carpeting, etc....not a good combo for a computer user. But we digress....