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POWER SUPPLY
The LC-12 comes with a fanless, DC-DC power supply that draws power from an
external 12V power brick. The basic idea is the same as the
picoPSU, although the circuit board that the LC-12 uses is bigger and more
complex. The default brick is rated for 60W, and, although Silverstone offers
a 120W upgrade, it's hard to imagine the case being able to provide enough cooing
to support that kind of heat output.
This PCB is the "inner" half of the power supply, converting 12V
into the various other required voltages.
The power brick that came with our sample was manufactured by a Taiwanese company
called Lien Chang. However, Silverstone advised us that they have since changed
suppliers for better quality control.
This is the 12V power brick that came with early versions of the LC-12.
Details about the power supply proved to be very difficult to come by. Aside
from the 60W capacity of the power brick, Silverstone does not list any specifications
for the power supply as a whole, and output specs are missing completely. Google
searches for the manufacturer of the PCB (Daystar) and the power brick (Lien
Chang) both turned up nothing, so we are unable to do much more than speculate.
We did run the power supply through some quick efficiency tests, but the results
should be taken with a grain of salt given that Silverstone has since switched
suppliers. That's probably a good thing, though, as the power supply did very
poorly in our test, and was unable to deliver a full 60W under any load conditions
that we tried. The highest output we could achieve was ~53W, with 3A on each
of the three major lines. Boosting any of the lines to 4A caused an immediate
shutdown. With only 3A (36W) available on the +12V line, we would expect many
systems to have issues with this, especially those that use full-size drives.
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OUTPUT & EFFICIENCY: Silverstone LC-12 Power Supply
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DC Output Voltage (V) + Current (A)
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Power Factor
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Total DC Output
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AC Input
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Calculated Efficiency
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|
+12V1
|
+5V
|
+3.3V
|
-12V
|
+5VSB
|
|
11.83
|
0.96
|
5.10
|
0.98
|
3.34
|
0.96
|
0.0
|
0.0
|
0.62
|
19.6
|
28.5
|
68.6%
|
|
11.53
|
1.82
|
5.06
|
1.94
|
3.32
|
2.70
|
0.0
|
0.0
|
0.66
|
39.8
|
54.4
|
73.1%
|
|
11.20
|
2.63
|
5.02
|
2.84
|
3.29
|
2.66
|
0.0
|
0.0
|
0.68
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52.5
|
73.1
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71.8%
|
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Standby: 1.6W / PF: 0.41
No Load: 4.0W / PF: 0.51
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The efficiency numbers for the power supply were miserable, barely poking above
70% when most good power supplies can at least hit 80%. In addition to shutting
down below 60W output, the +12V line also strayed out of regulation in our highest
load test. The 0.8V drop at this level was well beyond the 5% (0.6V) tolerance
required by ATX12V. Even with a paltry 1A on the +12V line, it was still almost
0.2V below nominal, and the large fluctuations with load did not inspire confidence.
To top everything off, the power supply made noise. Fanless it might have been,
but it emitted a sharp electronic squeal whenever it was running. The noise
wasn't loud, and might well have disappeared had it been enclosed, but it was
audible throughout the room during the test. The noise appeared to come from
the PCB, not the power brick, so it may still be a problem even in models that
ship with the newer brick.
We hope Silverstone's new supplier has improved on this. We are not confident
that this power supply could power anything but a very low power EPIA-based
system. Mini-ITX systems for Core Duo or Turion chips are out of the question.
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