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 AK6-600M provided ripple and noise levels below the maximum allowed, but they were too high when we pulled 600 W for us to consider this unit “flawless.”
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 21.2 mV | 37.4 mV | 51.4 mV | 59.8 mV | 80.4 mV |
| +12VB | 19.4 mV | 31.6 mV | 44.0 mV | 49.2 mV | 70.2 mV |
| +5 V | 12.6 mV | 12.8 mV | 15.6 mV | 18.2 mV | 20.2 mV |
| +3.3 V | 25.4 mV | 26.4 mV | 30.2 mV | 38.0 mV | 45.4 mV |
| +5VSB | 23.6 mV | 25.4 mV | 28.8 mV | 35.8 mV | 42.2 mV |
| -12 V | 62.4 mV | 78.4 mV | 95.2 mV | 94.4 mV | 113.4 mV |
Below you can see the waveforms of the outputs during test five.
Figure 17: +12VA input from load tester during test five at 603.4 W (80.4 mV)
Figure 18: +12VB input from load tester during test five at 603.4 W (70.2 mV)
Figure 19: +5V rail during test five at 603.4 W (20.2 mV)
Figure 20: +3.3 V rail during test five at 603.4 W (45.4 mV)
