Question about Compaq Refurbished 280WATT POWER SUPPLY FOR PROFESSIONAL WORKSTATION 5100 Power Supply

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i wants to know about components based calculation of output capacity
( output watts ) of an computer atx smps
if i am not wrong the way of components based calculation like this
for example if we are using 2nos of power transistor mje-13007 having max output of 80 watts each it means 80x2=160 watts ????????
if im right then plz check this link they say`s this is 200w atx smps but they are using power transistor 2sc4242 ( 400v and 40 watts means 40x2= 80 watts ) ??????????????
plz guide me i m confused
satish rajput

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Every device can be safely operated upto allowable temperature. If you design to remove heat, then for same power, temp would be low or for a particular temperature, it can cater more power handeling capacity. Here is the trick.
If the heatsink and force cooling is provided, the power rating can be easily increased. And this is the trick the company utilize the engineering to overdrive components. Even if insted of using high current schottky rectifiers like MBR3045WT (15A Each Channel) in low voltage side, they solder cathod of 1N5822 (3A Capacity)to metal plate and screwed to heatsink. But the transformers capacity is also reduced to using high frequency of SMPS 130KHz insted of earlier 66 or 33 KHz. I also found Good design Frontech 600Watt SMPS without HV line filter choke and without low voltage filtering capacitor.

The only testing is to connect load resistance to each voltage so that it must not fail. Another thing I can recomend, to check the bulky SMPS (heavy or weight high) during purchase as seal opening voids guarantee. Of course, seeing through vent hole will give you some idea if you are aware about electronics.

Posted on Jan 30, 2010

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Maximum output of any smps is not based solely on the type of power switching transistors used. One of the parameters which will be crucial is the Ic (Max collector current rating). But this by itself isn't the lone determining factor either.

Other design factors which will come into play are the switching transformer, its size and windings. A smaller transformer and smaller wire gauge windings will generally mean lower max power output.

Max power output measurements probably require a set of load resistors, volt and amp meters, monitoring the 3.3, 5, 12 volt lines.

I'm not an engineer, but have had numerous computer power supplies apart, repairing some, junking some. Quality of construction or lack thereof is generally obvious. PC Power and Cooling probably builds high quality units. There are plenty of cheap, low cost power supplies which frequently die after a year or two, sometimes taking a motherboard down with it.

Posted on Dec 22, 2007

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Can you advise me of a suitable replacement for my psu which as stopped working. The psu fitted is fsp400-60mdn which i cannot locate a new one.Any advice would be very helpful Phil.

Unless this is a proprietary power supply design (special type case, custom-made equipment, oddball power connectors, etc.) you should be able to use any ATX replacement power supply with a suitable output rating.

I'm guessing from the number you give that the one you have now is a 400-watt supply. You can put in a higher-rated one with no trouble. They're all very close in size and have standard mounting holes, and excess capacity won't hurt anything. In fact, since under-sizing the power supply is often why they go bad in the first place, putting in one with greater capacity is usually a good idea. There's very little difference in price for the higher power ones.

Most supplies will have enough connectors to work with your motherboard and drives. Just check the specifications to be sure. There are so many sources and supplies available that I won't try to recommend a particular brand. I've used many and they all seem to work just fine.

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My computer just died the morning. I removed the

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Technical Details
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11 +12V (White)
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13 +3.3V (Orange)
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16 PS-ON (Green)
17 COM (Black)
18 COM (Black)
19 COM (Black)
20 Blank
21 +5V (Red)
22 +5V (Red)
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