PC power supply. Connect monitor directly to PSU or power separately?

Hi
I'm concerned about overburdening my no-name 400w PSU.
I've quite a number of large fans and various devices and Molex Y-splitters
to power same.
My question is: Does plugging your monitor (19" Hitachi CM721f) into the PSU's power out connector, use many watts? (i.e. as many as the monitor consumes.)
Dumb question or what?
Thanks
Dumbo Darren
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Y-splitters
I assume you mean you are plugging the monitor's AC connecor into a provided AC output jack in the PSU.
this is perfictly fine and will not increase the load on the PSU.
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Darren wrote:

You will be pleased to know that the monitor doesn't use a single one of your 400W - as far as the monitor is concerned, the power supply just acts as a switched extension cord.
However, like any extension cord, it does have a maximum current rating for the socket that you plug the monitor in to. This will normally be on a label next to the socket and/or in the specification sheet for the power supply. This is normally rated in amps. There may be a different figure for the amps rating at 110V and the amps rating at 220-250V. Take that rating in amps (say 2A) and multiply it by your household voltage (say 250V). That gives 500 - the maximum number of watts that you can take from the socket.
Your monitor will also have a label on the back saying how much power it uses. As long as that is less than the watts figure you worked out above, then you are fine.
For a 19 inch monitor, this shouldn't be a problem. However, if you use a Y cable adapter and try to power two of them via the PC power supply, you will probably exceed the power supply's designed rating for the socket.
If you think, "Why would anyone want two monitors?", then you probably haven't tried it! I use a 17" monitor as my main work area and an old 15" monitor alongside for everthing else. I reckon it is far, far better than a 21" monitor - and a lot cheaper..However, I can't power the combination from the power supply mains outlet as the total power is more than the rating of the socket.
--

Sue







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| I'm concerned about overburdening my no-name 400w PSU.
You really should do better to find out how makes these things.
| I've quite a number of large fans and various devices and Molex Y-splitters | to power same. | | My question is: | Does plugging your monitor (19" Hitachi CM721f) into the PSU's power out | connector, use many watts? (i.e. as many as the monitor consumes.)
The AC power outlet is just a pass through. It does not involve any of the DC power wattage. However, it will have power limits of its own based on whether or not it is switched. It could be limited to 5 amps or even less. It should handle any monitor. It would usually be used to turn off the monitor when you turn off the computer. It is a common practice to plug in a monitor there.
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snipped-for-privacy@ipal.net wrote:

If this means what I think it means, I agree. All of the computers that I have seen which have failed dramatically (smoke, flames, dents in the metalwork where the capacitor bodies have impacted, etc) have done so because the power supply failed. The ones that have fried completely (eg taking out the hard drives, keyboard, graphics card,etc) have done so because the power supply failed. These have all been "no-name" supplies and I have yet to find a single faulty power supply made by one of the reputable market leaders (Digital & Compaq not included).
So, to paraphrase, find out who makes these things and buy better..
--

Sue



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Thanks very much for all the feedback.
The power supply is an 'Omni'.
I'll shop around for an Antec/Enermax etc
Thanks
Darren
wrote:

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When seeking a supply, then remember, a supply that is missing essential functions can both fail and take out keyboard, motherboard, etc. No acceptable supply will both fail and then damage other computer components. So that a supply does not harm other computer parts, the supply must state, in writing, that it includes essential functions. Many do not. IOW its manufacturer must supply a long list of numeric specifications. Missing spec numbers are how inferior supplies get dumped into the market - sold only on price.
For example, what are the specs for that Omni? Did they even bother to provide specs? When selling to the naive, a power supply vendor may hype watts rather then list essential internal functions that were standard on power supplies even 30 years ago. The naive assume more watts means higher quality - the Tim Allen concept of "more power".
Darren wrote:

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wrote:
| snipped-for-privacy@ipal.net wrote: |
|> |> | I'm concerned about overburdening my no-name 400w PSU. |> |> You really should do better to find out how makes these things. | | If this means what I think it means, I agree. All of the computers that | I have seen which have failed dramatically (smoke, flames, dents in the | metalwork where the capacitor bodies have impacted, etc) have done so | because the power supply failed. The ones that have fried completely (eg | taking out the hard drives, keyboard, graphics card,etc) have done so | because the power supply failed. These have all been "no-name" supplies | and I have yet to find a single faulty power supply made by one of the | reputable market leaders (Digital & Compaq not included). | | So, to paraphrase, find out who makes these things and buy better..
I've been lucky so far to not have such an exciting PS failure. But I have had many dull boring "just quits working" failures where swapping out does bring things back alive. And I have noticed that those with no names have the highest (significantly) failure rates. OTOH, at a place I worked which handles its own PC building and repair for several years, it actually was a financial gain to use the noname PSUs as the cost of swapping a few out every year, plus the labor to do so, didn't even come near what the cost would have been to put in famous brand reliable ones. It's much like the way data is transmitted through a communication line. The sweet point on the performance graph actually does involve pushing the speed to the point where errors can sometimes occur, which works out as long as you have a means to detect and retransmit (which TCP/IP does).
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