3R System AK 500 Power Supply Review
Ripple and Noise Tests
Contents
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 are 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 3R System AK 500 provided ripple and noise levels inside the appropriate range, as you can see in the table below.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 32.4 mV | 26.4 mV | 33.4 mV | 49.0 mV | 83.2 mV |
| +12VB | 32.2 mV | 26.8 mV | 32.2 mV | 49.8 mV | 82.6 mV |
| +5 V | 14.2 mV | 16.6 mV | 20.8 mV | 27.4 mV | 39.6 mV |
| +3.3 V | 16.4 mV | 17.6 mV | 20.4 mV | 24.6 mV | 28.8 mV |
| +5VSB | 16.2 mV | 16.6 mV | 18.8 mV | 21.4 mV | 24.6 mV |
| -12 V | 60.4 mV | 57.6 mV | 61.4 mV | 71.4 mV | 89.4 mV |
Below you can see the waveforms of the outputs during test five.
Figure 18: +12VA input from load tester during test five at 503.4 W (83.2 mV)
Figure 19: +12VB input from load tester during test five at 503.4 W (82.6 mV)
Figure 20: +5V rail during test five at 503.4 W (39.6 mV)
Figure 21: +3.3 V rail during test five at 503.4 W (28.8 mV)
Let’s see if we can pull more than 500 W from this unit.