DC Load Regulation and AC Ripple
DC Output Load Regulation
To simulate real world and maximum loading conditions, the Seasonic Platinum Series Fanless 460W PSU was connected to the load testers and supplied with a constant 115 VAC. In this test we are interested in seeing how well a PSU can maintain the various output voltages while operating under different loads.
The ATX12V V2.2 tolerance for voltages states how much each output (rail) is allowed to fluctuate and has tighter tolerances now for the +12V outputs. I have also included a second table of expanded tolerances (±1% to ±6%) for reference.
The following tables list the DC voltage results for the PSU while operating on 115 VAC, 60 Hz.
As you can see, the Platinum-460 Fanless PSU produced outstanding load regulation on all of the outputs across a broad range of loads; and meeting the claimed 2% "tight voltage regulation" for the three primary rails. Very impressive!
AC Ripple and Noise on the DC Outputs
The amount of AC ripple and noise present on the DC outputs was checked using a digital oscilloscope. This AC component may be present in the KHz range where most switching power supplies operate or it may be more prevalent at the 60 Hz line frequency. We adjust the O-scope time base to look for AC ripple at both low and high frequencies. The ATX12V V2.2 specification for DC output noise/ripple is defined in the ATX12V Power Supply Design Guide.
Ideally we would like to see no AC ripple (repetitive) or noise (random) on the DC outputs – the cleaner the better! But in reality there will always be some present. I measured the amplitude of the AC signal (in millivolts, peak-to-peak) to see how well the power supply complied with the ATX standard. The following table lists the ripple/noise results during all of the load tests for the main output voltages of interest.
The Seasonic Platinum-460 Fanless power supply exhibited excellent AC ripple suppression on all of the primary outputs and stayed well below the recommended values, even at full load.
More progress in the race to
More progress in the race to create a small silent desktop machine.
We’re not worthy.
We’re not worthy.
Fanless PSU’s aren’t much use
Fanless PSU’s aren’t much use IMHO, a PSU with an inaudible HDB fan is the way to go.
– accurate and also really
– accurate and also really effective good designed devie obviously!
Would have lover 10%
Would have lover 10% effiecency and à comparison with Gold serie
They tested 46 watts. That is
They tested 46 watts. That is exactly 10%.
Is it really silent? Yes,
Is it really silent? Yes, there is no fan, but it can produce a long pi sound when working under load.
I have heard this that is why it is difficult to decide. I want to have a completely silent computer, but what if this PSU doesn’t work as expected when it arrives? There is a Thermaltake Tt Toughpower DPS G 550W – I am looking for it on hardware.nl or amazon which should be great too – it has a 140mm fan. Well, it makes some sound. So, this is like a lottery, I think…