Power Supply Technical Tips

[BrandonHum]

I am wondering what to look for when looking at the internals of a power supply to judge the quality.

For example, do the specs of the two huge capacitors make a big difference? (like 2x100uF vs 2x800uF)

Or do the number of capacitors make a difference? What about the number and size of transformers?

 

[BrandonHum]

And if possible, could you provide an explanation of "why" for your answer?

Thanks!

 

[xonik]

Large filter capacitors (the biggest capacitors) do a better job of smoothing out the AC current prior to DC conversion. They should be high in capacitance and in voltage rating.

Large, extruded (one-piece) heatsinks ensure good cooling. They may also indicate a lower efficiency rating, which is bad, but at least you will have good cooling.

The use of toroidal (donut-shaped) transformers is desirable because it cuts down on EMI somewhat. These transformers are almost always used, at least in the power supplies I've encountered.

 

[Jeff]

Usually. The main determining factor in a power supplies quality is its weight. There might be some generic unit advertised as 550w and and another brand name product that is only 350w. And the brand name one will weight a good amount more than the generic one. And it is likely to output smoother and more stable power than the generic.

Another thing to see is how big the capacitors are. The bigger the better because it will be able to smooth out the voltage fluctuations. And look at the heatsinks, once again the bigger the better(bigger heatsink=heavier psu).