PC Power & Cooling Silencer 275 ATX Power Supply

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Question: Why spend extra for a power supply?

Answer: Besides the fact that this power supply is a perfect fit for the PC Power & Cooling’s Personal MidTower ATX case, the quality of manufacturing and performance under adverse conditions are serious considerations.

Question: The standard case comes with a power supply and there is nothing about the power supply’s quality I need be concerned about, right?

Answer: Well, yes and then again no. Yes, it is a power supply that converts AC to DC, but how well it does that consistently, and under what adverse conditions it remains solid at is more important. Important not only to the proper operation of the computer and its parts, but more important to your sanity with regard to troubleshooting a misbehaving PC. I recently dealt with a situation where after several months of chasing demons in a PC built for my son, the end cause of the problems was not the memory, the CPU, the motherboard, the cables or the drive. It was in fact a power supply that would fail to supply 12+ volts consistently, thus making it difficult to troubleshoot the wide range of failures occurring. The drop in volts was just enough to cause memory failures, freezes, but not enough to fail in such a manner as to be obvious, I actually had to meter the power supply. Once I changed the power supply those problems disappeared.

Potential Problems

There are four basic areas of concern with a power supply for us to consider:

Blackout: Complete loss of power. Some consider a voltage drop below about 80V to be a blackout, since most equipment will not operate below these levels.

Sag or Brownout: Decrease in voltage levels which can last for periods ranging from minute fractions of a second to hours. Can be caused by heavy equipment coming on line such as shop tools, elevators, compressors etc. (Pay close attention to the next point folks, because this occurs daily and is worse in the summer because of air conditioning !) Also occurs when utility companies deliberately reduce voltage levels to cope with peak load times.

Spike: An instantaneous and tremendous increase in voltage often caused by a direct lightning strike on a power line or when power returns after a blackout.

Surge: An substantial increase in voltage lasting a small fraction of a second, often caused when high powered appliances such as air conditioners are switched off. Or when the utility companies peak load ends and the grid start to return to “normal” voltage levels.

You cannot do much about a Blackout, the only resolution for a Blackout is an UPS (Uninterruptable Power Supply) which, depending on manufacturer, provides a range of power protections, the most notable being battery backup to give you time to shut your PC down without losing data. Some additional benefits, once again, manufacturer and model dependent, are surge, sag and spike protection for not only the PC, but your modem as well. UPS’s are often be confused with a Surge Protector, but the Surge Protector only works on surges and when designed right most spikes, but not sags and brownouts. The Surge Protector you are most familiar with is circuitry consisting of MOVs, capacitors, rod-core inductors etc. for suppressing surges and spikes usually embedded in what is referred to as a power strip.

Now that you can see that a UPS will shield a power supply from most of the problems from the grid, what if you do not have a UPS? You may want to consider the PC Power & Cooling Silencer 275 ATX power supply, it is simply the quietest power supply I ever heard. The only PC I have ever heard that was quieter was a PS/2 MCA based PC, which due to the design had no case fan or fan in the power supply.

Due to the attention to design and quality components the Silencer has a greater capacity to maintain voltage levels during sags than any other power supply that I am aware of. The Silencer also has better internal surge protection than any external surge protector I have known. It handles the spikes and surges, associated with living on the coast of the Gulf of Mexico, but these problems actually occur everywhere AC is available, some areas are just worse than others.

The Specifications

Operating Range:
90-135 VAC
180-270 VAC
Frequency: 47-63Hz
8.0A @ 115V
4.0A @ 230V
Efficiency: 70%
+5V @ 30A
+12V @ 10A
-5V @ 0.3A
-12V @ 1A
+3.3V @ 14A
+5VSB @ 850mA
+5V & +3.3V<150W
5% (±5, ±12)
1% (+3.3)
Ripple: 1% (p-p)
Hold Time: 20ms
PG Delay: 300ms
OV Protection: +3.3, +5
OC Protection: short circuit
Agency Approval: UL, ULC
Temperature: 0° -50° C
Noise: 34dB(A)
Compatibility: ATX (Rev. 2.03)
MB Connectors: 20-pin, 6 pin
Drive Connectors: 8 (2 mini)
MTBF: 70,000 hrs.


Even though the price has dropped from $125 to $89, it is still an expensive part, I acknowledge that, however I consider it an investment. I plan to move the power supply into a new PC Power & Cooling Full Tower Case when they are available within the next two months. PC Power & Cooling is my power supply vendor, period, end of story. Ultra quiet, capable and stable under the most adverse conditions and when combined with a UPS insure that power problems will not be of a concern. You know you are a computer geek when you’re not concerned that your power supply costs more than the cases.

Submitted by: Casca

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