FSP Twins 500 W Redundant PSU Review

Name: FSP Twins 500 W Redundant PSU
Brand: FSP

crmaris

on Mar 8th, 2017,

in Power Supplies.

Manufacturer: FSP

Protection Features Evaluation »

Ripple Measurements

You will see the ripple levels we measured on the rails of the FSP Twins 500 W in the following table. The limits are, according to the ATX specification, 120 mV (+12V) and 50 mV (5V, 3.3V, and 5VSB).

Ripple Measurements - FSP Twins 500
Test	12 V	5 V	3.3 V	5VSB	Pass/Fail
10% Load	56.6 mV	14.3 mV	22.3 mV	12.7 mV	Pass
20% Load	57.3 mV	13.8 mV	22.8 mV	13.5 mV	Pass
30% Load	55.0 mV	14.0 mV	23.3 mV	13.6 mV	Pass
40% Load	56.2 mV	14.0 mV	24.0 mV	14.6 mV	Pass
50% Load	55.6 mV	13.8 mV	24.3 mV	14.7 mV	Pass
60% Load	56.1 mV	13.9 mV	24.5 mV	15.3 mV	Pass
70% Load	58.8 mV	13.9 mV	25.7 mV	15.9 mV	Pass
80% Load	58.1 mV	14.1 mV	25.5 mV	17.3 mV	Pass
90% Load	62.9 mV	13.9 mV	26.3 mV	16.8 mV	Pass
100% Load	63.8 mV	14.2 mV	25.8 mV	17.6 mV	Pass
110% Load	64.3 mV	14.8 mV	26.4 mV	18.2 mV	Pass
Crossload 1	60.8 mV	15.7 mV	26.6 mV	14.7 mV	Pass
Crossload 2	63.5 mV	15.6 mV	23.3 mV	16.3 mV	Pass

Ripple at +12V isn't up to the levels we expected given the number of quality caps FSP used. The 5V and 5VSB rails are ripple-proof, though, and the 3.3V rail also performs pretty well in these tests.

Ripple at Full Load

You can see the AC ripple and noise the main rails registered (+12V, 5V, 3.3V, and 5VSB) in the following oscilloscope screenshots. The bigger the fluctuations on the oscilloscope's screen, the bigger the ripple/noise. We set 0.01 V/Div (each vertical division/box equals 0.01 V) as the standard for all measurements.