proSilence PCS-350 Fanless PSU

Power
Viewing page 2 of 4 pages. Previous 1 2 3 4 Next

SOME TECHNICAL DETAILS

Connectors - There are 5 wire sets:

  • 2 cables, 31" long, each with three 4-pin IDE drive connectors and 1 floppy drive connector
  • 1 cable, 12" long, with main 20-pin ATX connector
  • 1 cable, 12" long, for 12V (P4) connector
  • 1 cable, 12" long, for 3.3V connector

It's an odd mix: The 31" cables seem too long and the 12" cables are too short, especially as the cables exit the PSU from the top corner (as opposed to bottom), increasing the distance to the motherboard connections.

The usual label on the side of the PSU shows output ratings for the voltage lines.

The label on the sample unit says:

AC Input
110 VAC, 4A, 47-63 Hz
DC Voltage lines
+3.3V
+5V
+12V
-12V
-5V
+5VSB
Max Output
12A
18A
10A
0.5A
0.5A
-
Peak Output
14A
25A
14A
0.5A
0.5A
2.5A
Total Output
170W

One has to wonder where that 350W is? There is no information regarding load or line regulation tolerances.

The silentmaxx website says the proSilence PCS-350W v1.2 features:

  • Passive PFC (power factor correction)
  • ATX 2.03 compatible
  • P4 compatible
  • Operational in the temperature range of -22 to 167F (?!)
  • Improved power switch

Version 1.2 also has increased output on all its lines.

DC Voltage lines
+3.3V
+5V
+12V
-12V
-5V
Max Output
15A
21A
13A
0.5A
0.5A
Peak Output
17A
28A
17A
0.5A
0.5A
Total Output
197W

It is clear that the 350W rating of this PSU was obtained by using the normal convention of simply adding up the maximum output capability of each of its voltage lines. This does not, as their total output specification indicates, tell you anything much about the total power than can be delivered simultaneously, which would be normal in a real-use situation. Given that the real power capability (of version 1.1) is just 170W, the "350W" embedded in the model number is an unfortunate stretch. It seems rather misleading.

GETTING INSIDE

Lacking the tool to measure it, I cannot tell you how thick the metal of the case is except to say that it seems about double the thickness of ordinary PSU cases. It certainly feels hefty. The heatsink that covers the bulk of the visible area under the cover also looks very hefty. As the photos show, it appears that all the main heat producing components are mechanically connected to the big heatsink for cooling. The external heatsink is bolted directly to the internal one via 4 substantial bolts, and some thermal interface material can be seen around the edges where the two heatsinks meet.

The concept is simple enough: The heat generated by the PSU is meant to be transferred to the internal heatsink, which is physically and thermally coupled to the external heatsink. The external heatsink dissipates the heat to the outside via convection cooling.

The photo directly above shows a couple of unused white pin connectors directly in front of the coil. It's hard to see in this photo, but they look for all the world like fan connectors. It seems safe to presume that the main PSU board has been adapted from a conventional ATX PSU.

One other significant deviation from the norm is that the printed circuit board sits on the bottom of the PSU when it is installed in a case. In a conventional PSU, the PCB goes on the top, and the components hang down from it. It appears that the reversal was made to in order to take advantage of naturally rising heat convection. Note that the cover has ventilation holes to allow this heat to escape the PSU. In midsize ATX cases, however, this will provide only minimal cooling, as the top of the PSU is very close to the top panel of the case, and there is nowhere for the hot air to go. In a taller case, it would provide some cooling advantage if the case has ventilation vents on the back panel above the PSU. One has to think that the main cooling is normally via the heatsink on the back.



Previous 1 2 3 4 Next

Power - Article Index
Help support this site, buy from one of our affiliate retailers!
Search: