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Ripple Measurements
To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the HPT650M’s rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V, and 5VSB).
| Test | 12V | 5V | 3.3V | 5VSB | Pass/Fail |
|---|---|---|---|---|---|
| 10% Load | 28.8mV | 4.9mV | 4.7mV | 11.9mV | Pass |
| 20% Load | 19.8mV | 4.6mV | 5.0mV | 13.8mV | Pass |
| 30% Load | 17.5mV | 5.4mV | 5.4mV | 17.5mV | Pass |
| 40% Load | 18.8mV | 5.5mV | 5.3mV | 22.4mV | Pass |
| 50% Load | 19.7mV | 6.5mV | 5.6mV | 23.4mV | Pass |
| 60% Load | 21.6mV | 7.1mV | 6.1mV | 17.3mV | Pass |
| 70% Load | 21.6mV | 7.3mV | 6.6mV | 18.0mV | Pass |
| 80% Load | 22.9mV | 8.3mV | 8.2mV | 16.0mV | Pass |
| 90% Load | 23.8mV | 8.9mV | 8.6mV | 17.2mV | Pass |
| 100% Load | 25.6mV | 8.9mV | 8.9mV | 19.6mV | Pass |
| 110% Load | 26.9mV | 9.6mV | 9.6mV | 18.4mV | Pass |
| Cross-Load 1 | 19.0mV | 7.3mV | 9.3mV | 6.4mV | Pass |
| Cross-Load 2 | 25.9mV | 7.6mV | 5.7mV | 7.6mV | Pass |
All of the rails deliver clean voltages. It is nice to see such good results from a power supply that doesn't rely on extra filtering capacitors in its cables.
Ripple Oscilloscope Screenshots
The following oscilloscope screenshots illustrate the AC ripple and noise registered on the main rails (+12V, 5V, 3.3V and 5VSB). The bigger the fluctuations on the screen, the bigger the ripple/noise. We set 0.01 V/Div (each vertical division/box equals 0.01V) as the standard for all measurements.
Ripple At Full Load
Ripple At 110-Percent Load
Ripple At Cross-Load 1
Ripple At Cross-Load 2
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