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 PC Power & Cooling Silencer Mk III 600 W provided extremely low ripple and noise levels during all tests, as you can see in the table below.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 13.4 mV | 13.2 mV | 14.4 mV | 16.2 mV | 19.8 mV |
| +12VB | 13.8 mV | 14.6 mV | 15.2 mV | 17.0 mV | 22.4 mV |
| +5 V | 10.2 mV | 9.2 mV | 9.4 mV | 10.0 mV | 9.6 mV |
| +3.3 V | 8.2 mV | 8.6 mV | 9.0 mV | 10.0 mV | 16.4 mV |
| +5VSB | 12.2 mV | 12.4 mV | 15.2 mV | 16.8 mV | 20.2 mV |
| -12 V | 9.6 mV | 9.0 mV | 10.4 mV | 12.4 mV | 14.8 mV |
Below you can see the waveforms of the outputs during test five.
Figure 16: +12VA input from load tester during test five at 597.4 W (19.8 mV)
Figure 17: +12VB input from load tester during test five at 597.4 W (22.4 mV)
Figure 18: +5V rail during test five at 597.4 W (9.6 mV)
Figure 19: +3.3 V rail during test five at 597.4 W (16.4 mV)
Let’s see if we can pull more than 600 W from this unit.
