Corsair AX850 850 W Review

Name: Corsair AX850 850 W
Brand: Corsair

crmaris

on May 9th, 2011,

in Power Supplies.

Manufacturer: Corsair

Value & Conclusion »

Ripple Measurements

In the following table you will find the ripple levels that we measured on the main rails of AX850. According to ATX specification the limits are 120 mV (+12V) and 50 mV (5V & 3.3V).

Ripple Measurements
Test	12 V	5 V	3.3 V	Pass/Fail
20% Load	17.2 mV	9.6 mV	6.6 mV	Pass
40% Load	14.2 mV	9.2 mV	6.2 mV	Pass
50% Load	13.2 mV	9.4 mV	6.4 mV	Pass
60% Load	13.4 mV	9.8 mV	7.2 mV	Pass
80% Load	14.8 mV	12.2 mV	11.2 mV	Pass
100% Load	18.2 mV	11.6 mV	8.4 mV	Pass
Crossload 1	16.2 mV	12.8 mV	13.8 mV	Pass
Crossload 2	18.6 mV	11.4 mV	8.2 mV	Pass

Ripple? Where did you see any? All outputs are nearly flat. Seasonic once more did a terrific job in ripple/noise suppression.
Notice the higher ripple at +12V with 20% load, compared to the other tests with higher applied loads. This is happening because the main switches work in PWM mode at low loads and jump to FM mode at higher loads.

Ripple at Full Load

In the following oscilloscope screenshots you can see the AC ripple and noise that the main rails registered (+12V, 5V, 3.3V). 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 to 0.01V) as standard but sometimes we are forced to use 0.02 V/Div, meaning that the fluctuations will look smaller but actually this wont be the case. For the first screenshot we used 0.02 V/Div, so actually the registered ripple is much bigger than it seems (compared to the other screenshots where 0.01 V/Div was used)