Power Supply Voltage Tolerances and Measurements

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MrAl
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Re: Power Supply Voltage Tolerances and Measuremen

Post by MrAl » Tue Mar 09, 2010 3:52 pm

CeaSaR wrote:Where'd you find the ESR? I looked on the datasheet and couldn't find it. It wasn't listed on the site either.
If the TH part you listed is OK, I'll go with that.

CeaSaR

Hi again,


It isnt listed on the data sheet, i calculated it from tan(angle)...

ESR=tan(angle)/(2*pi*f*C)

where tan(angle) is usually spec'd with f=120Hz.

The cheaper part i mentioned has ESR slightly less than that cap.


BTW these caps are for the motherboard only or power supply too?
LEDs vs Bulbs, LEDs are winning.

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CeaSaR
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Re: Power Supply Voltage Tolerances and Measurements

Post by CeaSaR » Tue Mar 09, 2010 5:06 pm

The 2200 uF are for the PSU. I still have to verify that MOBO cap. I'm just about to tear into it again. May take a
bit longer than last time. NCIS is on. :grin:

CeaSaR
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CeaSaR
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Re: Power Supply Voltage Tolerances and Measurements

Post by CeaSaR » Tue Mar 09, 2010 7:29 pm

The 2nd value IS 820 uF 6.3 V. Much better view this time plus macro shot confirmed. Size 8mm x 12mm.
the 2200 measures 10mm x 20mm. Will look at those listed earlier. Will also look at what a replacement
PSU will cost. It is a Bestec ATX-250-12Z Rev D.

Thanks again for previous and future help.

CeaSaR

Edit: My cap.
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CeaSaR
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Re: Power Supply Voltage Tolerances and Measurements

Post by CeaSaR » Tue Mar 09, 2010 11:18 pm

Oh this is getting to me. On a hunch, I checked at MCM and I can upgrade my PSU for about $18 on sale!
Kinda make one sick to think you can buy bigger new stuff for so little. PSU here. Maybe I'll order one and
the parts to fix the old one plus some other stuff to make it all worthwhile. What's one more day.

CeaSaR
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MrAl
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Re: Power Supply Voltage Tolerances and Measuremen

Post by MrAl » Wed Mar 10, 2010 7:59 am

Hi again,


Oh yes ok, that's what i ended up doing too. I fixed the old supply and then bought a new one because
i found one for such a good price and it was a name brand too. I also bought one for a friend too so he
could have a decent power supply also. The prices were just too good to pass up.

I see that supply is a little bit older style, does it have all the connectors you need?
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Re: Power Supply Voltage Tolerances and Measuremen

Post by Robert Reed » Wed Mar 10, 2010 8:30 am

Wow-$16.99! I could hardly purchase just the out of the box items (wired Molex connectors and line cord) for that price. How do they do it?

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Re: Power Supply Voltage Tolerances and Measurements

Post by CeaSaR » Wed Mar 10, 2010 9:31 am

MrAl,

Yep, all the connectors needed, Molex, ATX and floppy. I don't plan to do any other upgrades as this is getting
on the old side for a computer. Once the PSU is working/replaced, it'll serve for quite a while before replacement.

Robert,

2 words: Bulk (and) China. Need I say more?

CeaSaR
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Re: Power Supply Voltage Tolerances and Measuremen

Post by MrAl » Wed Mar 10, 2010 11:49 am

Hi again,


Yes, they end up having trouble selling the older style stuff once the newer style come out
like the ones with the extra 8 pin CPU connector and the PCI Express power connectors.
I think that motivates them to sell for anything they can get for it after a while when they
sit on shelves for years. The cost to keep them (real estate) starts to exceed the amount
they can actually get for them even if they didnt lower the price. Once they lower the price
someone buys them and then they get that space back for the more current products.
It's a balance between losing money and breaking even, or even sometimes a balance between
losing SOME money vs losing MORE money as they sit around for years...loose a little now and
make money later rather than keep losing money.

It's interesting that that one even has a SATA power connector. Many times the older
ones dont even have that so they must be getting desperate for the space.
I had been looking at power supplies quite extensively not too long ago so i found out
a lot about what they are selling and for how much and of course what the output ratings
were coupled with the price and the type and number of connectors.
LEDs vs Bulbs, LEDs are winning.

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