Ripple and Noise Tests
Voltages at the power supply outputs must be as “clean” as possible, with no noise or oscillation (also known as “ripple”). The maximum ripple and noise levels allowed is 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures. We consider a power supply as being top-notch if it can produce half or less of the maximum allowed ripple and noise levels.
The Fractal Design Tesla R2 650 W provided ripple and noise levels within specifications, as you can see in the table below. When we pulled 650 W from this unit, ripple and noise levels were too close to the maximum allowed at +5 V, +3.3 V, and +5VSB outputs.
|Input||Test 1||Test 2||Test 3||Test 4||Test 5|
|+12VA||18.4 mV||27.4 mV||36.4 mV||37.2 mV||47.4 mV|
|+12VB||18.6 mV||28.2 mV||37.0 mV||36.8 mV||46.0 mV|
|+5 V||15.6 mV||17.0 mV||19.6 mV||27.4 mV||41.6 mV|
|+3.3 V||16.4 mV||17.2 mV||20.2 mV||26.2 mV||42.8 mV|
|+5VSB||15.4 mV||18.0 mV||22.4 mV||30.0 mV||47.8 mV|
|-12 V||21.8 mV||41.4 mV||52.8 mV||45.6 mV||49.4 mV|
Below you can see the waveforms of the outputs during test five.
Let’s see if we can pull more than 650 W from this unit.