Today’s PSU market is extremely competitive and replete with information that can mislead home computer builders that have not been fully educated on PSU criteria. We tend to look for wattage ratings as a sign of a good PSU, and that is where we begin to make a mistake in the process of purchasing or choosing wisely.
Do you know why?
The role of Power Factor Correction ( PFC) PC power supplies are actually switching power supplies A switching power supply converts power from your AC line into the DC voltages needed to run your computer. A standard switching power supply doesn't draw its power from the AC line smoothly. It actually draws sudden gulps of current. That "messes up" your AC power lines. In some offices with lots of equipment with switching power supplies, you can actually overheat wiring and trip current breakers because of the way they gulp power. Power factor correction smooths out the gulps to keep your AC line all nice and clean. If you're in Europe then the power factor correction feature is probably required in your PSU. In most other parts of the world it's your choice. If you just have a run-of-the-mill computer or two in your home then power factor correction isn't nearly as important, but PFC protection will definitely result in "cleaner" AC lines. Your power company will be happier if you have power factor correction because nasty reactive loads like power supplies with no PFC mess up their AC power grid and make their lives more difficult.
There are two kinds of power factor correction: active PFC and passive PFC. Active PFC is more expensive and does a better job of keeping your AC line clean. Passive PFC is cheaper but is still an improvement over not having PFC protection. Power factor correction makes the PSU more expensive so very low priced PSUs rarely come with either type of PFC protection. If you're really looking to clean up your PSU's power consumption habits then active PFC does a much better job than passive PFC to achieve that goal.
Protection Features Manufacturers that offer numerous Protection options on their PSU’s normally indicate a higher quality product, while a lower quality unit will not offer as many of these features. While this area is often overlooked, experts recommend that you consider these features as you evaluate a power supply.
When you look for Protection features, please understand that manufacturers will often use “acronyms” to identify the protections offered by their company. We have listed the self-explanatory terms and Acronyms to assist you in understanding what features are offered for specific power supplies:
- OVP = Over Voltage Protection
- OCP = Over Current Protection
- OPP = Over Power Protection
- SCP = Short Circuit Protection
- UVP = Under Voltage Protection
- OTP = Over Temperature Protection
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